Lit Bits: April 28, 2010

From the recent medical literature...

1. Computer Model May Improve Detection of Serious Bacterial Infection in Young Children with Fever

Laurie Barclay, MD. April 27, 2010 — Use of a computer model may improve detection of serious bacterial infection in young children with fever, according to the results of a 2-year, prospective cohort study reported in the April 20 issue of the BMJ.

"In most cases, the cause of a febrile illness is a self limiting, presumed viral, infection, but 5-10% of febrile children have serious bacterial infections such as pneumonia, urinary tract infection, meningitis, bacteraemia, or bone or joint infection (which usually present with fever)," write Jonathan C. Craig, MD, from the University of Sydney in Sydney, Australia, and colleagues. "These conditions can be difficult to distinguish from viral infections and benefit from early antibiotic therapy. The consequences of a delayed or missed diagnosis can be serious and, occasionally, fatal."

The goals of this study were to examine current methods for diagnosis and treatment of young children presenting with a febrile illness but suspected of having serious bacterial infection, and to develop and test a multivariable model aiming to differentiate serious bacterial infections from self-limiting nonbacterial illnesses.

Between July 1, 2004, and June 30, 2006, a total of 15,781 children younger than 5 years presented with a febrile illness to the emergency department of The Children's Hospital at Westmead, Australia. Physicians conducted a standardized clinical evaluation including mandatory entry of 40 clinical features into the hospital's electronic recordkeeping system. Standard radiologic and microbiological tests and follow-up confirmed or excluded serious bacterial infections.

Primary endpoints were diagnosis of 1 of 3 key types of serious bacterial infection (urinary tract infection, pneumonia, and bacteremia) and the diagnostic accuracy of the clinical computer-assisted decision-making model and clinician judgment. Follow-up rate was 93%.

For the 3 types of infections, the combined prevalence was 7.2% (95% confidence interval [CI], 6.7% - 7.5%). Among cases of febrile illness, urinary tract infection was diagnosed in 3.4% (95% CI, 3.2% - 3.7%), pneumonia in 3.4% (95% CI, 3.1% - 3.7%), and bacteremia in 0.4% (95% CI, 0.3% - 0.5%).

The appropriate test (urine culture, chest radiograph, or blood culture) was performed in more than 94% of children with serious bacterial infections. Antibiotics were prescribed for 66% of children with urinary tract infection; 69% of those with pneumonia; and 81% of those with bacteremia, as well as for 20% of those without bacterial infection.

Using multinomial logistic regression, the investigators developed a diagnostic model based on the data from the clinical evaluations and the confirmed diagnosis. Although sensitivity was low (10% - 50%) and specificity was high (90% - 100%) for physicians' diagnoses of bacterial infection, the clinical diagnostic model yielded a broad range of values for sensitivity and specificity.

"Emergency department physicians tend to underestimate the likelihood of serious bacterial infection in young children with fever, leading to undertreatment with antibiotics," the study authors write. "A clinical diagnostic model could improve decision making by increasing sensitivity for detecting serious bacterial infection, thereby improving early treatment."

Limitations of this study include lack of microbiological and radiologic verification in all children and uncertain validity of the physician estimates of disease.

In an accompanying editorial, Matthew J. Thompson, MBChB, DPhil, and Ann Van den Bruel, MD, PhD, from the University of Oxford, in Oxford, United Kingdom, note that measuring vital signs and evaluating the child's overall state of illness are key to proper diagnosis of febrile illness.

"In practice, clinicians use many different diagnostic strategies," Drs. Thompson and Van den Bruel write. "Calculating the probability of a condition on the basis of 28 predictors is only feasible with a computerised algorithm, for which popular handheld electronic devices and computerised records are invaluable. But before widespread implementation, we will need to have evidence showing the effect of using such a model on patient management and outcomes."

The National Health and Medical Research Council of Australia supported this study. The study authors and editorialists have disclosed no relevant financial relationships.

BMJ. 2010;340:c1594. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/20406860

2. Thirty-day Outcomes of ED Patients Undergoing Electrical Cardioversion for Atrial Fibrillation or Flutter

Scheuermeyer FX, et al. Acad Emerg Med 2010;17:408-415.

Objectives: While the short-term (less than 7-day) safety and efficiency of electrical cardioversion for emergency department (ED) patients with atrial fibrillation or flutter have been established, the 30-day outcomes with respect to stroke, thromboembolic events, or death have not been investigated.

Methods: A two-center cohort of consecutive ED patients undergoing cardioversion for atrial fibrillation or flutter between January 1, 2000, and September 30, 2007, was retrospectively investigated. This cohort was probabilistically linked with both a regional ED database and the provincial health registry to determine which patients had a subsequent ED visit or hospital admission, stroke, or thromboembolic event or died within 30 days. In addition, trained reviewers performed a detailed chart abstraction on 150 randomly selected patients, with emphasis on demographics, vital signs, medical treatment, and predefined adverse events. Hemodynamically unstable patients or those whose condition was the result of an underlying acute medical diagnosis were excluded. Data were analyzed by descriptive methods.

Results: During the study period, 1,233 patients made 1,820 visits for atrial fibrillation or flutter to the ED. Of the 400 eligible patients undergoing direct-current cardioversion (DCCV), no patients died, had a stroke, or had a thromboembolic event in the following 30 days (95% confidence interval [CI] = 0.0 to 0.8% for all outcomes). A total of 141 patients were included in the formal chart review, with five patients (3.5%, 95% CI = 0.5% to 6.6%) failing cardioversion, six patients (4.3%, 95% CI = 0.9% to 7.6%) having a minor adverse event that did not change disposition, and five patients (3.5%, 95% CI = 0.5% to 6.6%) admitted to hospital at the index visit.

Conclusions: Cardioversion of patients with atrial fibrillation or flutter in the ED appears to have a very low rate of long-term complications.

3. Why Expensive Placebos Work Better

It's long been recognized that the placebo effect is extremely powerful; anywhere between 35 and 75 percent of people get better after receiving pretend medical treatments, such as sugar pills. A few years ago, Tor Wager, a neuroscientist at Columbia University, wanted to figure out why placebos were so effective. His experiment was brutally straightforward: he gave college students electric shocks while they were stuck in an fMRI machine. (The subjects were well compensated, at least by undergraduate standards.) Half of the people were then supplied with a fake pain-relieving cream. Even though the cream had no analgesic properties—it was just a hand moisturizer—people given the pretend cream said the shocks were significantly less painful. The placebo effect eased their suffering. Wager then imaged the specific parts of the brain that controlled this psychological process. He discovered that the placebo effect depended entirely on the prefrontal cortex, the center of reflective, deliberate thought. When people were told that they'd just received pain-relieving cream, their frontal lobes responded by inhibiting the activity of their emotional brain areas (like the insula) that normally respond to pain. Because people expected to experience less pain, they ended up experiencing less pain. Their predictions became self-fulfilling prophecies.

The placebo effect is a potent source of self-help. It demonstrates the power of the prefrontal cortex to modulate even the most basic bodily signals. Once this brain area comes up with reasons to experience less pain—the cream is supposed to provide pain relief—those reasons become powerful distortions. Unfortunately, the same rational brain areas responsible for temporarily reducing suffering also mislead us about many daily decisions. The prefrontal cortex can turn off pain signals, but it can also cause a person to ignore the feelings that lead to choosing the best [option]. In these situations, conscious thoughts interfere with good decision-making.

Look, for example, at this witty little experiment. Baba Shiv, a neuroeconomist at Stanford, supplied a group of people with Sobe Adrenaline Rush, an "energy" drink that was supposed to make them feel more alert and energetic. (The drink contained a potent brew of sugar and caffeine that, the bottle promised, would impart "superior functionality.") Some participants paid full price for the drinks, while others were offered a discount. After drinking the product, participants were asked to solve a series of word puzzles. Shiv found that people who'd paid discounted prices consistently solved about 30 percent fewer puzzles than the people who'd paid full price for the drinks. The subjects were convinced that the stuff on sale was much less potent, even though all the drinks were identical. "We ran the study again and again, not sure if what we got had happened by chance or fluke," Shiv says. "But every time we ran it, we got the same results."

Why did the cheaper energy drinks prove less effective? According to Shiv, consumers typically suffer from a version of the placebo effect. Since they expect cheaper goods to be less effective, they generally are less effective, even if the goods are identical to more expensive products. This is why brand-name aspirin works better than generic aspirin and why Coke tastes better than cheaper colas, even if most consumers can't tell the difference in blind taste tests. "We have these general beliefs about the world—for example, that cheaper products are of lower quality—and they translate into specific expectations about specific products," said Shiv. "Then, once these expectations are activated, they start to really impact our behavior." The rational brain distorts the sense of reality, so the ability to properly assess the alternatives is lost. Instead of listening to the trustworthy opinions generated by our emotional brains, we follow our own false assumptions.

Researchers at Caltech and Stanford recently lifted the veil on this strange process. Their experiment was organized like a winetasting. Twenty people sampled five cabernet sauvignons that were distinguished solely by their retail prices, with bottles ranging in cost from five dollars to ninety dollars. Although the people were told that all five wines were different, the scientists weren't telling the truth: there were only three different wines. This meant that the same wines often reappeared, but with different price labels. For example, the first wine offered during the tasting—it was a bottle of a cheap California cabernet—was labeled both as a five-dollar wine (its actual retail price) and as a forty-five-dollar wine, a 900 percent markup. All of the red wines were sipped by each subject inside an fMRI machine.

Not surprisingly, the subjects consistently reported that the more expensive wines tasted better. They preferred the ninety­dollar bottle to the ten-dollar bottle and thought the forty-five­dollar cabernet was far superior to the five-dollar plonk. By conducting the winetasting inside an fMRI machine—the drinks were sipped via a network of plastic tubes—the scientists could see how the brains of the subjects responded to the different wines. While a variety of brain regions were activated during the experiment, only one brain region seemed to respond to the price of the wine rather than the wine itself: the prefrontal cortex. In general, more expensive wines made parts of the prefrontal cortex more excited. The scientists argue that the activity of this brain region shifted the preferences of the winetasters, so that the ninety-dollar cabernet seemed to taste better than the thirty-five­dollar cabernet, even though they were actually the same wine.

Of course, the wine preferences of the subjects were clearly nonsensical. Instead of acting like rational agents—getting the most utility for the lowest possible price—they were choosing to spend more money for an identical product. When the scientists repeated the experiment with members of the Stanford University wine club, they got the same results. In a blind tasting, these semi-experts were also misled by the made-up price tags. "We don't realize how powerful our expectations are," says Antonio Rangel, the neuroeconomist at Caltech who led the study. "They can really modulate every aspect of our experience. And if our expectations are based on false assumptions”—like the assumptions that more expensive wine tastes better—“they can be very misleading.”

Excerpted from Jonah Lehrer's fascinating book, How We Decide (Boston: Houghton Mifflin Harcourt, 2009), 146-149. Lehrer is a Rhodes scholar with a strong interest in neuroscience. http://jonahlehrer.com/about

4. Accidental Injection of Epinephrine Into Fingers Not a Cause for Concern

NEW YORK (Reuters Health) Apr 09 - There are no significant local or systemic effects when an epinephrine autoinjector is accidentally discharged into a finger, according to an article in the Annals of Emergency Medicine on March 29.

Ischemia in the affected finger is rare, and when it does occur, it can be managed with vasodilators, Dr. Vikhyat S. Bebarta, from Wilford Hall Medical Center in San Antonio, Texas, and colleagues report.

These reassuring findings also show that contrary to what was once widely believed, epinephrine mixtures may be safe for digital nerve blocks during minor procedures, the researchers say. (Autoinjectors typically contain more epinephrine than is found in local anesthetic mixes, they note.)

The findings are based on a study of 127 accidental epinephrine injections into fingers. These cases were ones for which the researchers had follow-up data; their overall cohort consisted of 365 patients with accidental epinephrine injections to the hand who called a poison control center, including 213 with fingers involved.

No patient had any significant local or systemic side effects, and symptoms resolved completely in all cases. The researchers treated 29 patients (23%) with either topical nitroglycerin, local phentolamine injection, or local terbutaline. Forty patients used warm soaks alone.

Four patients (3.1%) were reported as having an ischemic finger and all were treated with vasodilator therapy and sent home. In two of the patients, symptoms resolved within 2 hours of injection.

In an editorial, Dr. Adam J. Singer of Stony Brook University, New York, summarizes "the take-home message": in the absence of signs of poor perfusion (pain, pallor, paresthesias, prolonged capillary refill, and cool temperature), patients with an accidental autoinjector stick require no treatment and can be discharged home. If digital ischemia is present, "dilute phentolamine in lidocaine should be injected subcutaneously into the site until the area turns pink."

Ann Emerg Med 2010.

5. Disease Progression in Hemodynamically Stable Patients Presenting to the Emergency Department with Sepsis

Glickman SW, et al. Acad Emerg Med 2010;17:383-390.

Background: Aggressive diagnosis and treatment of patients presenting to the emergency department (ED) with septic shock has been shown to reduce mortality. To enhance the ability to intervene in patients with lesser illness severity, a better understanding of the natural history of the early progression from simple infection to more severe illness is needed.

Objectives: The objectives were to 1) describe the clinical presentation of ED sepsis, including types of infection and causative microorganisms, and 2) determine the incidence, patient characteristics, and mortality associated with early progression to septic shock among ED patients with infection.

Methods: This was a multicenter study of adult ED patients with sepsis but no evidence of shock. Multivariable logistic regression was used to identify patient factors for early progression to shock and its association with 30-day mortality.

Results: Of 472 patients not in shock at ED presentation (systolic blood pressure above 90 mm Hg and lactate less than 4 mmol/L), 84 (17.8%) progressed to shock within 72 hours. Independent factors associated with early progression to shock included older age, female sex, hyperthermia, anemia, comorbid lung disease, and vascular access device infection. Early progression to shock (vs. no progression) was associated with higher 30-day mortality (13.1% vs. 3.1%, odds ratio [OR] = 4.72, 95% confidence interval [CI] = 2.01 to 11.1; p ≤ 0.001). Among 379 patients with uncomplicated sepsis (i.e., no evidence of shock or any end-organ dysfunction), 86 (22.7%) progressed to severe sepsis or shock within 72 hours of hospital admission.

Conclusions: A significant portion of ED patients with less severe sepsis progress to severe sepsis or shock within 72 hours. Additional diagnostic approaches are needed to risk stratify and more effectively treat ED patients with sepsis.

6. A Clinical Decision Rule to Reduce Use of X-Rays in Patients with Chest Pain

A rule based on three criteria was 100% sensitive and 36% specific for determining which patients could forgo chest x-rays.

Hess EP, Stiell IG, et al. CJEM 2010;12(2):128-134

Objectif : Nous avons établi une règle de décision clinique pour déterminer qui, parmi les patients qui se présentent à l'urgence avec des douleurs thoraciques et un possible syndrome coronarien aigu (SCA), doit subir une radiographie pulmonaire.

These bilingual Canadians… Sorry about that. Let me repeat this in English.

Objective: We derived a clinical decision rule to determine which emergency department (ED) patients with chest pain and possible acute coronary syndrome (ACS) require chest radiography.
Methods: We prospectively enrolled patients over 24 years of age with a primary complaint of chest pain and possible ACS over a 6 month period. Emergency physicians completed standardized clinical assessments and ordered chest radiographs as appropriate. Two blinded investigators independently classified chest radiographs as "normal," "abnormal not requiring intervention" and "abnormal requiring intervention," based on review of the radiology report and the medical record. The primary outcome was abnormality of chest radiographs requiring acute intervention. Analyses included interrater reliability assessment (with κ statistics), univariate analyses and recursive partitioning.

Results: We enrolled 529 patients during the study period between Jul. 1, 2007, and Dec. 31, 2007. Patients had a mean age of 59.9 years, 60.3% were male, 4.0% had a history of congestive heart failure and 21.9% had a history of acute myocardial infarction. Only 2.1% (95% confidence interval [CI] 1.1%-3.8%) of patients had radiographic abnormality of the chest requiring acute intervention. The κ statistic for chest radiograph classification was 0.81 (95% CI 0.66-0.95). We derived the following rule: patients can forgo chest radiography if they have no history of congestive heart failure, no history of smoking and no abnormalities on lung auscultation. The rule was 100% sensitive (95% CI 32.0%-40.4%) and 36.1% specific (95% CI 32.0%-40.4%).

Conclusion: This rule has potential to reduce health care costs and enhance ED patient flow. It requires validation in an independent patient population before introduction into clinical practice.

7. The Risk of Intra-abdominal Injuries in Pediatric Patients with Stable Blunt Abdominal Trauma and Negative Abdominal Computed Tomography

Hom J. Acad Emerg Med. 2010; 17:469–475.

Objectives: This review examines the prevalence of intra-abdominal injuries (IAI) and the negative predictive value (NPV) of an abdominal computed tomography (CT) in children who present with blunt abdominal trauma.

Methods: MEDLINE, EMBASE, and Cochrane Library databases were searched. Studies were selected if they enrolled children with blunt abdominal trauma from the emergency department (ED) with significant mechanism of injury requiring an abdominal CT. The primary outcome measure was the rate of IAI in patients with negative initial abdominal CT. The secondary outcome measure was the number of laparotomies, angiographic embolizations, or repeat abdominal CTs in those with negative initial abdominal CTs.

Results: Three studies met the inclusion criteria, comprising a total of 2,596 patients. The overall rate of IAI after a negative abdominal CT was 0.19% (95% confidence interval [CI] = 0.08% to 0.44%). The overall NPV of abdominal CT was 99.8% (95% CI = 99.6% to 99.9%). There were five patients (0.19%, 95% CI = 0.08% to 0.45%) who required additional intervention despite their initial negative CTs: one therapeutic laparotomy for bowel rupture, one diagnostic laparotomy for mesenteric hematoma and serosal tear, and three repeat abdominal CTs (one splenic and two renal injuries). None of the patients in the latter group required surgery or blood transfusion.

Conclusions: The rate of IAI after blunt abdominal trauma with negative CT in children is low. Abdominal CT has a high NPV. The review shows that it might be safe to discharge a stable child home after a negative abdominal CT.

8. Naproxen, Sumatriptan Effective for Headache Recurrence after ED Discharge

By Michelle Rizzo. NEW YORK (Reuters Health) Apr 22 - Naproxen and sumatriptan are equally effective in relieving headache that recurs after emergency department (ED) discharge, according to findings published online March 22nd in the Annals of Emergency Medicine.

"Fifty-one percent of patients discharged from an ED after treatment for acute migraine, or other recurrent headache disorders, will use prescription medication to treat headache recurrence," Dr. Benjamin W. Friedman, of Albert Einstein College of Medicine, Bronx, New York, told Reuters Health by e-mail.

In a randomized trial, Dr. Friedman and his colleagues compared oral sumatriptan (100 mg) to naproxen (500 mg) for treating patients whose headaches were controlled in the ED but then recurred after discharge. All of the patients were contacted by phone 48 hours after discharge.

The main outcome was the change in pain intensity during the 2-hour period after treatment. The authors also assessed satisfaction with the medication and adverse effects.

The report includes data on 383 (93%) of the 410 patients who enrolled in the study. Overall, 280 patients (73%) had headache after discharge that was either mild (n = 89) or moderate to severe (n = 191). One hundred ninety-six (51%) took the investigational medication, including 88 with migraine.

The two groups had similar improvements in pain intensity, as measured on a validated 11-point verbal numeric rating scale, with a mean increase of 4.3 points in the naproxen group and 4.1 points in the sumatriptan group.

Findings were nearly identical among a subset of patients with acute migraine without aura (4.3 points for naproxen versus 4.2 points for sumatriptan). These patients were analyzed twice according to a-priori design: once as a homogenous subgroup and then again combined with all the patients.

The rate of adverse effects was 19% with naproxen and 26% with sumatriptan. Common adverse effects in both groups included gastrointestinal, dizziness/feeling lightheaded or weak, and drowsiness.

Overall, 71% of patients in the naproxen group and 75% in the sumatriptan group said they would want the same medication the next time.

"Although many medications are now available to treat acute migraine, the goal of complete and sustained headache relief remains elusive," Dr. Friedman said.

Ann Emerg Med 2010.

9. Do Brain-Training Programs Work?

by Greg Miller on April 20, 2010. Science Now. Play a computer game, boost your IQ—that's the claim made by some software companies pedaling so-called brain-training programs. It's probably an empty promise, according to the largest study to date of brain-training software, which finds no evidence of general cognitive benefits. Yet the study's limitations give brain-training advocates plenty to gripe about.

The idea for the study originated with a BBC science television show, Bang Goes the Theory. Producers contacted Adrian Owen at the MRC Cognition and Brain Sciences Unit in Cambridge, U.K., to help design an experiment to test the efficacy of computer brain training. Many of these programs are set up like a game, and playing along supposedly boosts memory, attention, and other cognitive functions. But few rigorous studies have been conducted on them, and many researchers question whether even the best programs do anything more than make people better at the game itself. For example, there's little solid research to suggest that using these programs has a beneficial effect on overall cognition that carries over into daily life.

In the new study, Owen and colleagues developed two online training programs and tested them in 11,430 healthy adults who registered on a Web site set up by the BBC. One group trained on a program that emphasized reasoning and problem-solving skills, and another group trained on a program that emphasized different skills, including short-term memory and attention. A third, control group, essentially did busywork, hunting for answers to general knowledge questions on the Internet. All participants were asked to "train" for at least 10 minutes, three times a week for 6 weeks, and all received a battery of cognitive tests before and after this 6-week period.

Not surprisingly, people in both training groups got better at the tasks they actually practiced. But that's as far as it went. "None of the brain-training tasks transferred to other mental or cognitive abilities beyond what had been specifically practiced," Owen's co-author and MRC colleague Jessica Grahn said at a press conference this morning announcing the results, which are published online today in Nature.

Brain-training advocates are not impressed, however. "This article makes big claims out of a single negative finding," says Torkel Klingberg, a neuroscientist at the Karolinska Institute in Stockholm and founder of a company that makes computer brain-training programs to improve working memory and other cognitive functions. Klingberg has published one of the few studies demonstrating that the benefits of training can generalize beyond a specific task. Among other qualms with the new study, he notes that subjects trained an average of only about 3 hours in total, and—for all the researchers know—may have done so with the TV blaring in the background or other distractions.

Although Klingberg says he agrees with the authors that many of the brain-training products on the market are probably ineffective, he argues that just because Owen and colleagues developed a training program and showed it didn't work doesn't mean that all such programs are worthless. "That does not mean that cognitive functions cannot be trained, or that all training paradigms lack effect," he says.

10. Some Success Fighting Heart Disease

Ron Winslow. Wall Street Journal, April 6, 2010. Good news from the front line in the battle against cardiovascular disease: The heart-attack rate among elderly Americans appears to be falling sharply.

The rate of hospital admissions for heart attack was 23% lower in 2007 than in 2002, according to a just-published analysis of Medicare data, with 228,170 fee-for-service Medicare patients admitted in 2007 compared with 297,653 in 2002. That suggests there were nearly 87,000 fewer heart-attack admissions in 2007 than would have been expected had the rate remained constant.

The report covers only the nearly 30 million Medicare beneficiaries in the traditional fee-for-service part of the federal health-care program for the elderly. If the findings are extrapolated based on 38 million Medicare participants, including those enrolled in so-called Medicare Advantage managed-care plans, researchers estimate a 2007 total of 319,063 heart-attack admissions, representing a reduction of 97,000 versus comparable figures in 2002.

"It's remarkable what has been accomplished," says Harlan Krumholz, a cardiologist at Yale University School of Medicine and principal investigator for the study. He terms the rapid decline in a major public health marker as "breathtaking."

Behind the drop, he and other heart experts believe, is the cumulative impact of a variety of prevention initiatives that public-health groups, professional organizations and payers of health care have mounted over the past two decades to change health habits and improve treatment of heart patients.

Quit-smoking campaigns, growing awareness of the importance of exercise and healthy diets, increasing use of medicines to control blood pressure and cholesterol and efforts to encourage doctors and hospitals to follow evidence-based guidelines when treating heart patients are among the potential contributing factors. "It looks like our effort with preventive medicine, with guidelines and a systematic approach to caring for patients, is paying off," says Sidney Smith, a cardiologist at University of North Carolina, Chapel Hill, and past president of the American Heart Association, who wasn't involved with the study.

Still, the progress comes with concerns…

Full-text (free): http://online.wsj.com/article/SB10001424052702304017404575166193617582042.html

11. Can CT Angiography of the Brain Replace Lumbar Puncture in the Evaluation of Acute-onset Headache after a Negative Noncontrast Cranial CT Scan?

McCormack RF, et al. Acad Emerg Med. 2010;17: 444–451

Objectives: The primary goal of evaluation for acute-onset headache is to exclude aneurysmal subarachnoid hemorrhage (SAH). Noncontrast cranial computed tomography (CT), followed by lumbar puncture (LP) if the CT is negative, is the current standard of care. Computed tomography angiography (CTA) of the brain has become more available and more sensitive for the detection of cerebral aneurysms. This study addresses the role of CT/CTA versus CT/LP in the diagnostic workup of acute-onset headache.

Methods: This article reviews the recent literature for the prevalence of SAH in emergency department (ED) headache patients, the sensitivity of CT for diagnosing acute SAH, and the sensitivity and specificity of CTA for cerebral aneurysms. An equivalence study comparing CT/LP and CT/CTA would require 3,000 + subjects. As an alternative, the authors constructed a mathematical probability model to determine the posttest probability of excluding aneurysmal or arterial venous malformation (AVM) SAH with a CT/CTA strategy.

Results: SAH prevalence in ED headache patients was conservatively estimated at 15%. Representative studies reported CT sensitivity for SAH to be 91% (95% confidence interval [CI] = 82% to 97%) and sensitivity of CTA for aneurysm to be 97.9% (95% CI = 88.9% to 99.9%). Based on these data, the posttest probability of excluding aneurysmal SAH after a negative CT/CTA was 99.43% (95% CI = 98.86% to 99.81%).

Conclusions: CT followed by CTA can exclude SAH with a greater than 99% posttest probability. In ED patients complaining of acute-onset headache without significant SAH risk factors, CT/CTA may offer a less invasive and more specific diagnostic paradigm. If one chooses to offer LP after CT/CTA, informed consent for LP should put the pretest risk of a missed aneurysmal SAH at less than 1%.

12. Fever as nature’s engine?

Fowler AW. BMJ 2009;339:b3874

Data suggest that the use of paracetamol (aka acetaminophen) to reduce the body temperature and alleviate the symptoms of flu is counterproductive.

Infectious organisms are adapted to the temperature of the part of the body they colonise. Rhinoviruses, which infect the cooler upper airway and sinuses, grow best at 33-35ºC, so inhaling air at about 45ºC for 20 minutes significantly improves the symptoms of a common cold. Conversely, treating the common cold with aspirin causes a significant increase in the rate of production of the virus. Moreover, if fever is suppressed in ferrets infected with flu virus, illness is prolonged.

The effect of lowering or raising body temperatures in humans with flu has not been studied, but there are good reasons to treat flu by encouraging the temperature to rise to 40ºC for at least 24 hours. The lack of such research may be due to a deep seated fever phobia stemming from pre-scientific medicine, when fever was perceived as an illness in itself. However, in the 17th century Thomas Sydenham said, "Fever is nature’s engine which she brings into the field to remove her enemy," the potential of which remains unrecognised by the public and the medical profession.

13. Heat or Cold Packs for Neck and Back Strain: A Randomized Controlled Trial of Efficacy

Garra G, et al. Acad Emerg Med. 2010; 17:484–489.

Objectives: Acute back and neck strains are very common. In addition to administering analgesics, these strains are often treated with either heat or cold packs. The objective of this study was to compare the analgesic efficacy of heat and cold in relieving pain from back and neck strains. The authors hypothesized that pain relief would not differ between hot and cold packs.

Methods: This was a randomized, controlled trial conducted at a university-based emergency department (ED) with an annual census of 90,000 visits. ED patients older than 18 years old with acute back or neck strains were eligible for inclusion. All patients received 400 mg of ibuprofen orally and then were randomized to 30 minutes of heating pad or cold pack applied to the strained area. Outcomes of interest were pain severity before and after pack application on a validated 100-mm visual analog scale (VAS) from 0 (no pain) to 100 (worst pain), percentage of patients requiring rescue analgesia, subjective report of pain relief on a verbal rating scale (VRS), and future desire for similar packs. Outcomes were compared with t-tests and chi-square tests. A sample of 60 patients had 80% power to detect a 15-mm difference in pain scores.

Results: Sixty patients were randomized to heat (n = 31) or cold (n = 29) therapy. Mean (±standard deviation [SD]) age was 37.8 (±14.7) years, 51.6% were female, and 66.7% were white. Groups were similar in baseline patient and pain characteristics. There were no differences between the heat and cold groups in the severity of pain before (75 mm [95% CI = 66 to 83] vs. 72 mm [95% CI = 65 to 78]; p = 0.56) or after (66 mm [95% CI = 57 to 75] vs. 64 mm [95% CI = 56 to 73]; p = 0.75) therapy. Pain was rated better or much better in 16/31 (51.6%) and 18/29 (62.1%) patients in the heat and cold groups, respectively (p = 0.27). There were no between-group differences in the desire for and administration of additional analgesia. Twenty-five of 31 (80.6%) patients in the heat group and 22 of 29 (75.9%) patients in the cold group would use the same therapy if injured in the future (p = 0.65).

Conclusions: The addition of a 30-minute topical application of a heating pad or cold pack to ibuprofen therapy for the treatment of acute neck or back strain results in a mild yet similar improvement in the pain severity. However, it is possible that pain relief is mainly the result of ibuprofen therapy. Choice of heat or cold therapy should be based on patient and practitioner preferences and availability.

14. Generalized Petechial Rashes in Children with Parvovirus B19

Parvovirus was the most common cause of generalized petechial rashes during a 2007 pediatric parvovirus B19 outbreak.

Edmonson MB et al. Pediatrics 2010 Apr; 125: e787-e792.

Objectives: Human parvovirus B19 infection is associated not only with erythema infectiosum (fifth disease) but also, rarely, with purpuric or petechial rashes. Most reports of these atypical rashes describe sporadic cases with skin lesions that have distinctively focal distributions. During a community outbreak of fifth disease, we investigated a cluster of illnesses in children with generalized petechial rashes to determine whether parvovirus was the causative agent and, if so, to describe more fully the clinical spectrum of petechial rashes that are associated with this virus.

METHODS: Systematic evaluation was conducted by general pediatricians of children with petechial rashes for evidence of acute parvovirus infection.

RESULTS: During the outbreak, acute parvovirus infection was confirmed in 13 (76%) of 17 children who were evaluated for petechial rash. Confirmed case patients typically had mild constitutional symptoms, and most (11 [85%] of 13) had fever. Petechiae were typically dense and widely distributed; sometimes accentuated in the distal extremities, axillae, or groin; and usually absent from the head/neck. Most case patients had leukopenia, and several had thrombocytopenia. Parvovirus immunoglobulin M was detected in 8 (73%) of 11 acute-phase serum specimens, and immunoglobulin G was detectable only in convalescent specimens. Parvovirus DNA was detected in all 7 tested serum specimens, including 2 acute-phase specimens that were immunoglobulin M–negative. All case patients had brief, uncomplicated illnesses, but 6 were briefly hospitalized and 1 underwent a bone marrow examination. Two case patients developed erythema infectiosum during convalescence.

CONCLUSIONS: During an outbreak of fifth disease, parvovirus proved to be a common cause of petechial rash in children, and this rash was typically more generalized than described in case reports. Associated clinical features, hematologic abnormalities, and serologic test results are consistent with a viremia-associated illness that is distinct from and occasionally followed by erythema infectiosum.

15. Unplanned ICU Transfers Often Preventable but Are Not Typically Due to Clinical Error

Terry Hartnett. April 12, 2010 (Washington, DC) — Transfers to the intensive care unit (ICU) that occur within 24 hours of presentation at the emergency department (ED) are primarily the result of a worsening of the initial condition or the development of a new problem. Very few of these transfers are due to diagnostic error or inappropriate treatment, according to a report presented here at Hospital Medicine 2010: Society of Hospital Medicine Annual Meeting.

The general consensus is that these transfers can be avoided, but a study presented by lead investigator Srinivas Bapoje, MD, MPH, a hospitalist at the Denver Health Medical Center in Colorado, suggests that improving triage and monitoring in the ED might result in immediate appropriate transfer from the ED to the ICU.

Dr. Bapoje told Medscape Internal Medicine that the accepted thinking on why so many patients end up in the ICU when they were not originally triaged there from the ED has been that clinical errors lead to unplanned transfers.

"Most of the patients in our study went to the ICU within 24 hours, and many within the first 6 hours," he said. "It seems clear that these patients likely met ICU criteria in the ED," said Dr. Bapoje. "We need to screen patients better."

The study involved 152 patients. The 2 most common diagnoses were respiratory failure (24%) and acute coronary syndrome (11%).

"Errors in care accounted for the transfer of 29 patients (19%), but in 15 of 29 patients (52%) the errors were in triage, because 14 of 15 (93%) met ICU admission criteria while still in the emergency department," Dr. Bapoje and his colleagues reported.

The study found 4 primary reasons for unplanned ICU transfers:

• Triage errors from the ED. This occurred in 15 cases (10% of the total), 14 of which (9%) were due to overlooked severity; only 1 (0.7%) of the unplanned ICU transfers was due to a diagnostic error. None of the transfers were the result of inadequate assessment.
• Worsening of the presenting condition. This was true for close to half of the patients in the study, with 73 patients (48%) experiencing worsening (68 of which were spontaneous). There were only 5 errors in assessment or treatment (3%).
• Development of a new problem. A significant number (59 patients [39%]) experienced this situation.
• Critical lab values. Only 5 cases (3%) fell into this category.

Dr. Bapoje told Medscape Internal Medicine that a rapid response team was used in the management of 106 of the study patients, but there was no recognized difference in outcome from those managed conventionally.

The researchers also found that mortality decreased for patients transferred to the ICU in the first 24 hours of hospital admission, compared with patients transferred after the initial 24 hours (4% vs 22%).

Still, Dr. Bapoje found that 29 (19%) transfers might have been prevented. "If the transfer occurs from the floor to the ICU, it adds to the cost and lengthens the stay," he said. "When the transfer occurs directly from the ED, it allows us to manage resources better," he noted.

A faculty member at the conference, Mary Jo Gorman, MD, FHM, founder and chief executive officer of Advances ICU Care, based in St. Louis, Missouri, told Medscape Internal Medicine that the results are not surprising, but she agreed that they point to the need for better observation and a quicker response to changes in the patient's condition.

"Hospitalists are increasingly being asked to fill the gap of intensivists in the ICU," said Dr. Gorman. "We need to closely monitor these patients and proactively intervene when necessary," she said.

Dr. Gorman's company monitors patients through a telemedicine system that puts a monitor and camera in each patient's room. The data feeds are monitored around the clock and allow for a quick response to any worsening or change in condition.

Dr. Bapoje said that although the deterioration of a patient's condition cannot be alleviated, the hospitalist who is based in the hospital around the clock can do a better job of monitoring and providing a quick response.

The study did not receive commercial support. Dr. Bapoje and Dr. Gorman have disclosed no relevant financial relationships.

Hospital Medicine 2010: Society of Hospital Medicine (SHM) Annual Meeting: Abstract 19. Presented April 9, 2010.

16. Is Risk for Venous Thromboembolism Affected by Route and Type of Menopausal Hormone Therapy?

Results of a large observational study suggest that transdermal (in contrast with oral) estrogens do not raise risk.

Although hormone therapy (HT) now is recommended only for short-term relief of menopausal symptoms, risk for idiopathic venous thromboembolism (VTE) is greatest during the first year of treatment. To determine if route of administration or type of concomitant progestogen affects risk for VTE, investigators analyzed data from a prospective cohort study of more than 80,000 French women (mean age at entry, 54) who completed biennial questionnaires for a mean of 10 years. The study was partially funded by a manufacturer of transdermal delivery systems.

During follow-up, 549 first idiopathic VTEs (134 pulmonary emboli and 415 deep venous thromboses) occurred. Past users (i.e., those with no use within 3 months before questionnaire completion) and never users of HT had similar VTE risk. Analysis adjusted for potential confounders showed that users of oral, but not transdermal (patch or gel), estrogen had substantially higher risk for VTE than did never users (hazard ratio, 1.7). No significant associations were found between VTE and concomitant micronized progesterone (Prometrium), pregnane derivatives including medroxyprogesterone acetate (Provera), or nortestosterone derivatives (including norethindrone acetate). However, the norpregnane derivatives nomegestrol acetate and promegestone (not marketed in the U.S.) were associated with significantly higher VTE risk (HR, 1.8).

Comment: This observational study cannot provide irrefutable evidence that transdermal estrogens do not raise VTE risk, but it is the largest study to date that suggests the possibility; moreover, the findings mirror those of earlier studies (JW Womens Health Apr 5 2007). Given that oral, but not transdermal, estrogens can raise levels of factors that lead to clotting, these findings are biologically plausible. The data also provide reassurance that progestogens marketed in this country (when prescribed with transdermal estrogen) do not raise VTE risk.

— Robert W. Rebar, MD

Published in Journal Watch Women's Health April 8, 2010. Citation: Canonico M et al. Postmenopausal hormone therapy and risk of idiopathic venous thromboembolism: Results from the E3N cohort study. Arterioscler Thromb Vasc Biol 2010 Feb; 30:340.

17. A Descriptive Comparison of Ultrasound-guided Central Venous Cannulation of the Internal Jugular Vein to Landmark-based Subclavian Vein Cannulation

Theodoro D, et al. Acad Emerg Med. 2010;17: 416–422.

Objectives: The safest site for central venous cannulation (CVC) remains debated. Many emergency physicians (EPs) advocate the ultrasound-guided internal jugular (USIJ) approach because of data supporting its efficiency. However, a number of physicians prefer, and are most comfortable with, the subclavian (SC) vein approach. The purpose of this study was to describe adverse event rates among operators using the USIJ approach, and the landmark SC vein approach without US.

Methods: This was a prospective observational trial of patients undergoing CVC of the SC or internal jugular veins in the emergency department (ED). Physicians performing the procedures did not undergo standardized training in either technique. The primary outcome was a composite of adverse events defined as hematoma, arterial cannulation, pneumothorax, and failure to cannulate. Physicians recorded the anatomical site of cannulation, US assistance, indications, and acute complications. Variables of interest were collected from the pharmacy and ED record. Physician experience was based on a self-reported survey. The authors followed outcomes of central line insertion until device removal or patient discharge.

Results: Physicians attempted 236 USIJ and 132 SC cannulations on 333 patients. The overall adverse event rate was 22% with failure to cannulate being the most common. Adverse events occurred in 19% of USIJ attempts, compared to 29% of non–US-guided SC attempts. Among highly experienced operators, CVCs placed at the SC site resulted in more adverse events than those performed using USIJ (relative risk [RR] = 1.89, 95% confidence interval [CI] = 1.05 to 3.39).

Conclusions: While limited by observational design, our results suggest that the USIJ technique may result in fewer adverse events compared to the landmark SC approach.

18. Are Acetaminophen/NSAID Combinations More Effective Than One Drug Alone?

A systematic review indicates that combinations are more effective for relieving acute pain.

Although many clinicians recommend combining acetaminophen (paracetamol) and nonsteroidal anti-inflammatory drugs (NSAIDs) for acute pain management, the evidence for this practice has been mixed. An international team of investigators performed a systematic review of all randomized controlled trials (RCTs) in which paracetamol/NSAID combinations were compared to either class of drug alone for managing acute postoperative pain. The study was funded by the manufacturer of a paracetamol/ibuprofen combination tablet.

Twenty RCTs involving 1852 patients compared paracetamol/NSAID combinations with paracetamol alone. An analgesic combination was more effective than acetaminophen alone for at least one of three measures (pain score, need for supplemental analgesia, globally assessed pain relief) in 16 studies (80%). The mean reduction in pain intensity was 35%, and the mean reduction in need for supplemental analgesics was 39%. Fourteen studies involving 1129 patients compared the efficacy of an analgesic combination to that of an NSAID alone. Nine studies (64%) demonstrated that the combination was more effective. The mean reduction in pain intensity was 38%, and the mean reduction in need for analgesic supplementation was 31%. The incidence of side effects did not differ significantly between combination therapy and either single-drug therapy.

Comment: This systematic review supports the use of a combination of acetaminophen and NSAIDs for acute pain. The postoperative pain models used in these studies (orthopedic; ear, nose, and throat; gynecological; general; and dental surgery) likely translate well to other acute pain contexts.

— Emily L. Brown, MD, and Ron M. Walls, MD, FRCPC, FAAEM. Published in Journal Watch Emergency Medicine April 9, 2010. Citation: Ong CK et al. Combining paracetamol (acetaminophen) with nonsteroidal antiinflammatory drugs: A qualitative systematic review of analgesic efficacy for acute postoperative pain. Anesth Analg 2010 Apr; 110:1170.

19. Changes in Rabies Postexposure Prophylaxis Regimen

The CDC recommends changing the vaccination schedule from five to four doses.

Rupprecht CE et al. MMWR Recomm Rep 2010 Mar 19; 59:1

Link: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5902a1.htm

20. Thrombolytic Therapy Appears Safe Even in Stroke Mimics

Susan Jeffrey. April 6, 2010 — A new retrospective study suggests prompt treatment with tissue plasminogen activator (tPA) within 3 hours of symptom onset is safe even for patients who ultimately are found not to have had a stroke.

Outcomes showed that patients with conditions that simulate acute ischemic stroke, so-called stroke mimics, underwent treatment without any symptomatic intracerebral hemorrhage (ICH), the most feared complication of treatment.

"It may be that when you give tPA to people who don't have a stroke, the [hemorrhage] risk is much lower," lead study author Sean I. Savitz, MD, from the Department of Neurology at the University of Texas Medical School at Houston, speculated.

Time is brain, he said, and the pressure is on in the emergency department to make a decision on whether or not to treat. "That kind of approach can miss other things and lead you to treating things that are not actually stroke. There's not enough time to determine that this really is a seizure, or really is a migraine, or might be something else," he told Medscape Neurology.

The indication from this retrospective study at least is that that approach is safe even for patients who don’t have stroke, but prospective studies would help to better establish the safety of treating stroke mimics, he added.

Their findings were published online March 24 and will appear in the April 27 issue of Neurology.
Clock Is Ticking

Newer imaging modalities, such as computed tomographic (CT) angiography, magnetic resonance angiography, or transcranial Doppler, can show large artery occlusions, and diffusion-weighted imaging is very sensitive for ischemic stroke, the study authors write, but these techniques are not universally available.

No large study has looked at the outcomes of patients treated with tPA who were ultimately found to have a stroke mimic, such as seizure, complicated migraine, or functional deficits, or those assumed to have an averted stroke, that is, those without an infarct on magnetic resonance imaging (MRI) but who were not found to have another diagnosis. This latter group was called neuroimaging-negative cerebral ischemia (NNCI) in this analysis.

The investigators performed a retrospective review of patients treated with intravenous tPA within 3 hours of symptom onset between June 2004 and October 2008, identified from their stroke registry. They recorded admission National Institutes of Health Stroke Scale (NIHSS) scores, modified Rankin score, length of stay, any incidence of symptomatic ICH, and discharge diagnosis.

In all, 512 patients received tPA during that period of which 21% were found not to have an infarct on imaging.

Stroke mimics, those in whom another diagnosis was established, accounted for 14%. Their average age was 55 years, median admission NIHSS score was 7, median discharge NIHSS score was 0, median length of stay was 3 days, and none of these patients had symptomatic ICH after treatment. The most common alternate diagnoses among these patients were seizure, complicated migraine, and conversion disorder.

The remaining 7% fell into the NNCI group. The average age in this group was 61 years, median admission NIHSS score again was 7, median discharge NIHSS score again was 0, median length of stay was identical at 3 days, and, again, none had symptomatic ICH.
Their data, and those of others, they conclude, support treatment with tPA in those with suspected acute ischemic stroke, even when alternate diagnoses are being considered.

"Because the risk of emergently treating [stroke mimics], such as migraine, are low, and there is a loss of potential benefit in withholding treatment if the patient is indeed having a stroke, we favor intravenous tPA treatment if the patient meets Food and Drug Administration and American Heart Association criteria for thrombolysis," the study authors write.

"Subsequent studies after tPA initiation can be performed to better clarify the etiology in cases where the diagnosis is uncertain," they add. "Further prospective investigations are needed to establish the safety of thrombolysis in [stroke mimics] and NNCI."

"Swift and Sure"

In an editorial accompanying the publication, Jeffrey L. Saver, MD, from the University of California, Los Angeles, and William G. Barsan, MD, from the University of Michigan, Ann Arbor, point out that the new study shows the outcome of lytic exposure in mimic patients was "benign, with no cases reported of intracranial hemorrhage (0/82), systemic hemorrhage (0/69), or orolingual edema (0/76)."

The rate of mimics in this series, though, is higher than in prior studies, they note, "reflecting the distinctive and explicit policy of the Houston group to treat patients early, even if the diagnosis is still uncertain." Most other centers, they write, prefer more diagnostic certainty even though it could mean worsening neurologic outcomes.

Between the poles of diagnostic certainty and rapid treatment "lie happy mediums," they write. Although investigation continues, they suggest that a "reasonable target" based on previous studies would be a door-to-needle time of 60 minutes or less, with a neurovascular mimic rate of 3% or less where noncontrast CT alone is used, and 1% or less with more advanced modalities.

"Many tools are available to improve hyperacute stroke diagnosis and reduce mimic treatment rates, including formal assessment tools for prehospital personnel and emergency physicians, telestroke consultation by remote stroke expert physicians, and multimodal CT and MRI," Dr. Saver and Dr. Barsan conclude. "As these approaches are more widely implemented in regional stroke systems of care, thrombolytic treatment decisions can increasingly be both swift and sure."

Neurology. Published online March 24, 2010.

21. Airway Obstructions in Children Are Uncommon but Often Fatal

Nancy Fowler Larson. April 20, 2010 — Although only a small percentage of children incur airway obstruction from foreign bodies (FBs), a significant proportion of those cases result in death, according to a study published in the April issue of the Archives of Otolaryngology—Head & Neck Surgery.

Each year, approximately 2.5 million American children experience airway FBs (A-FBs) or esophageal FBs (E-FBs), which lead to as many as 2000 fatalities. Previous studies have demonstrated that half of such patients had no causal history, and 20% were misdiagnosed and mismanaged for at least 1 month.

"Delay of proper treatment inevitably increases the risk of complications and mortality in these patients," write Rahul Shah, MD, from the Division of Otolaryngology, Children's National Medical Center, George Washington University Medical Center, Washington, DC, and colleagues.
To pinpoint national trends regarding treatment of A-FBs and E-FBs in pediatric patients, the investigators studied information from the national Kids' Inpatient Database (KID) 2003 for those younger than 20 years.

The KID data that year came from close to 3 million pediatric discharges from 3438 hospitals. Of those, 2771 children had been admitted for FB airway obstructions. Fifty-nine percent were boys, 55% were younger than 2 years, and the mean age was 3.5 years. Other findings were as follows:

• 3.4% (n = 94) of children with FBs died in the hospital
• 25% of objects involved in all deaths met standards set by the Consumer Products Safety Commission
• 58% of FBs in fatal and nonfatal cases were nonorganic; 42% were food, with similar fatality numbers in each group (Χ2P = .65)
• Treatment procedures included bronchoscopy (52%), esophagoscopy (28%), and tracheotomy (1.7%)

Teaching hospitals were the treatment location for 71% of cases. The average charges were $34,652, with regional differences (P less than .001) and with greater expense at children's hospitals (P = .03). The mean hospital stay was 6.4 days and entailed 2.4 procedures.

The researchers noted that although children younger than 3 years were involved in most obstructions from edible objects, older children accounted for many of the nonfood cases.

"Prior studies have shown that children younger than 3 years are at higher risk for A-FBs and E-FBs. Our data corroborate this finding, as 80% of children with recovered organic FBs were younger than 3 years," the authors write. "However, only about 60% of children with inorganic FBs were younger than this age."

The mean age of pediatric patients whose FBs were caused by nonfoods was 4.3 years. That prompted an alert for physicians to more frequently suspect FBs when faced with an older child in respiratory distress.

Several limitations to the study were noted. First, any inaccurate data from the KID would have been included in the study. Second, biases may exist for 2 reasons: the researchers' decision to use E911 (inhalation and ingestion of food causing obstruction of respiratory tract or suffocation) and E912 (inhalation and ingestion of other object causing obstruction of respiratory tract or suffocation) International Classification of Diseases, Ninth Revision, Clinical Modification, codes only, and because a portion of the data-use agreement prevented discussion of a variable when its frequency was less than 10 sampled admissions.

The investigators called on teaching hospitals to increase and diversify training for the removal of airway obstructions.

"Bronchoscopic removal of FBs is standard in the treatment of these children; however, the dearth of actual cases makes this skill difficult to learn and to assess in trainees," the authors write. "To resolve this deficiency, alternative educational paradigms for FB retrieval may need to be considered."

The study authors have disclosed no relevant financial relationships.

Arch Otolaryngol Head Neck Surg. 2010;136:373-379.

Lit Bits: April 2, 2010

From the recent medical literature...

1. Clinical Features from the H&P That Predict the Presence or Absence of Pulmonary Embolism in Symptomatic ED Patients: Results of a Prospective, Multicenter Study

Courtney DM, et al. Ann Emerg Med. 2010;55:307-315.e1.

Study objective
Prediction rules for pulmonary embolism use variables explicitly shown to estimate the probability of pulmonary embolism. However, clinicians often use variables that have not been similarly validated, yet are implicitly believed to modify probability of pulmonary embolism. The objective of this study is to measure the predictive value of 13 implicit variables.

Methods
Patients were enrolled in a prospective cohort study from 12 centers in the United States; all had an objective test for pulmonary embolism (D-dimer, computed tomographic angiography, or ventilation-perfusion scan). Clinical features including 12 predefined previously validated (explicit) variables and 13 variables not part of existing prediction rules (implicit) were prospectively recorded at presentation. The primary outcome was venous thromboembolism (pulmonary embolism or deep venous thrombosis), diagnosed by imaging up to 45 days after enrollment. Variables with adjusted odds ratios from logistic regression with 95% confidence intervals not crossing unity were considered significant.

Results
Seven thousand nine hundred forty patients (7.2% venous thromboembolism positive) were enrolled. Mean age was 49 years (standard deviation 17 years) and 67% were female patients. Eight of 13 implicit variables were significantly associated with venous thromboembolism; those with an adjusted odds ratio (OR) greater than 1.5 included non-cancer-related thrombophilia (OR 1.99), pleuritic chest pain (OR 1.53), and family history of venous thromboembolism (OR 1.51). Implicit variables that predicted no venous thromboembolism outcome included substernal chest pain, female sex, and smoking. Nine of 12 explicit variables predicted a positive outcome of venous thromboembolism, including patient history of pulmonary embolism or deep venous thrombosis in the past, unilateral leg swelling, recent surgery, estrogen, hypoxemia, and active malignancy.

Conclusion
In symptomatic outpatients being considered for possible pulmonary embolism, non-cancer-related thrombophilia, pleuritic chest pain, and family history of venous thromboembolism increase probability of pulmonary embolism or deep venous thrombosis. Other variables that are part of existing pretest probability systems were validated as important predictors in this diverse sample of US emergency department patients.

Full-text (free): http://www.annemergmed.com/article/S0196-0644(09)01735-1/fulltext

2. Does Absence of Coronary Artery Calcification Exclude Obstructive Coronary Artery Disease?

In symptomatic patients, overall sensitivity of a CAC score of 0 for predicting absence of obstructive CAD was only 45%.

Gottlieb I, et al. J Am Coll Cardiol 2010; 55:627.

Objectives: This study was designed to evaluate whether the absence of coronary calcium could rule out 50% coronary stenosis or the need for revascularization.

Background: The latest American Heart Association guidelines suggest that a calcium score (CS) of zero might exclude the need for coronary angiography among symptomatic patients.

Methods: A substudy was made of the CORE64 (Coronary Evaluation Using Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors) multicenter trial comparing the diagnostic performance of 64-detector computed tomography to conventional angiography. Patients clinically referred for conventional angiography were asked to undergo a CS scan up to 30 days before.

Results: In all, 291 patients were included, of whom 214 (73%) were male, and the mean age was 59.3 ± 10.0 years. A total of 14 (5%) patients had low, 218 (75%) had intermediate, and 59 (20%) had high pre-test probability of obstructive coronary artery disease. The overall prevalence of 50% stenosis was 56%. A total of 72 patients had CS = 0, among whom 14 (19%) had at least 1 50% stenosis. The overall sensitivity for CS = 0 to predict the absence of 50% stenosis was 45%, specificity was 91%, negative predictive value was 68%, and positive predictive value was 81%. Additionally, revascularization was performed in 9 (12.5%) CS = 0 patients within 30 days of the CS. From a total of 383 vessels without any coronary calcification, 47 (12%) presented with 50% stenosis; and from a total of 64 totally occluded vessels, 13 (20%) had no calcium.

Conclusions: The absence of coronary calcification does not exclude obstructive stenosis or the need for revascularization among patients with high enough suspicion of coronary artery disease to be referred for coronary angiography, in contrast with the published recommendations. Total coronary occlusion frequently occurs in the absence of any detectable calcification.

3. Potential of an age adjusted D-dimer cut-off value to improve the exclusion of pulmonary embolism in older patients: a retrospective analysis of three large cohorts

Douma RA, et al. BMJ 2010;340:c1475

Objectives: In older patients, the the D-dimer test for pulmonary embolism has reduced specificity and is therefore less useful. In this study a new, age dependent cut-off value for the test was devised and its usefulness with older patients assessed.
Design Retrospective multicentre cohort study.

Setting: General and teaching hospitals in Belgium, France, the Netherlands, and Switzerland.

Patients: 5132 consecutive patients with clinically suspected pulmonary embolism.

Intervention: Development of a new D-dimer cut-off point in patients aged more than 50 years in a derivation set (data from two multicentre cohort studies), based on receiver operating characteristics (ROC) curves. This cut-off value was then validated with two independent validation datasets.

Main outcome measures: The proportion of patients in the validation cohorts with a negative D-dimer test, the proportion in whom pulmonary embolism could be excluded, and the false negative rates.

Results: The new D-dimer cut-off value was defined as (patient’s age x 10) µg/l in patients aged more than 50. In 1331 patients in the derivation set with an "unlikely" score from clinical probability assessment, pulmonary embolism could be excluded in 42% with the new cut-off value versus 36% with the old cut-off value (below 500 µg/l). In the two validation sets, the increase in the proportion of patients with a D-dimer below the new cut-off value compared with the old value was 5% and 6%. This absolute increase was largest among patients aged more than 70 years, ranging from 13% to 16% in the three datasets. The failure rates (all ages) were 0.2% (95% CI 0% to 1.0%) in the derivation set and 0.6% (0.3% to 1.3%) and 0.3% (0.1% to 1.1%) in the two validation sets.

Conclusions: The age adjusted D-dimer cut-off point, combined with clinical probability, greatly increased the proportion of older patients in whom pulmonary embolism could be safely excluded.

Full-text (free): http://www.bmj.com/cgi/content/full/340/mar30_3/c1475

4. Children with Food-Related Anaphylaxis Need Access to 2 Epinephrine Injections

Nancy Fowler Larson. April 1, 2010 — Keeping 2 doses of epinephrine on hand is recommended for children with life-threatening food allergies, according to a study published online March 22 in Pediatrics.

Approximately 3 million children in the United States have food allergies, and that number is growing. Food allergies are the chief cause of anaphylaxis, a sometimes-fatal allergic response, which progresses quickly to constrict the airway, irritate the skin and intestines, and/or affect heart rhythm. It is treated with an injection of epinephrine (adrenaline), which stimulates the heart, and elevates blood pressure, metabolic rate, and blood glucose concentration.

A number of small studies recommend that children who have experienced anaphylaxis brought on by food allergies should carry several doses of epinephrine. The suggestion brings up issues of cost and logistics.

"Therefore, we sought to more accurately define the likelihood of receiving dose of epinephrine for food-related anaphylaxis and to characterize the children for whom this was medically necessary," write Carlos A. Camargo Jr, MD, DrPH, from the Department of Emergency Medicine, Division of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital, Boston, and colleagues.

Using charts from Massachusetts General Hospital and Children's Hospital Boston, investigators reviewed 605 cases of 1255 patients whose mean age was 5.8 years. A total of 62% were boys. All subjects arrived at the emergency department (ED) between 2001 and 2006 with allergic reactions related to foods, typically nuts and milk. The investigators measured acute reactions using the International Classification of Diseases, Ninth Revision, Clinical Modification, criteria.

An allergic reaction to 2 or more organ systems or the presence of hypotension (below 70 mm Hg + [age x 2 years] for children under 10 years old, and below 90 mm Hg for children 10 - 18 years old) after exposure to an allergy-causing food was used to define anaphylaxis. Mean ± standard error and a 95% confidence interval (CI) were used to derive data. Statistical significance was achieved with a 2-sided P value of less than .05 in multivariable analysis, with use of unweighted numbers of visits to determine risk factors for a second dose of epinephrine.

Of Those Needing Epinephrine, 12% Required Second Dose

The results show that more than half (52%; 95% CI, 48% - 57%) of the subjects met the criteria for anaphylaxis stemming from foods, among other findings:

• Before their arrival at the ED, 31% of patients with anaphylaxis had received 1 dose of epinephrine, and 3% had received more than 1 dose.
• Once in the ED, 20% of those with anaphylaxis were treated with epinephrine; the others received antihistamines (59%) or corticosteroids (56%).
• During the entirety of their allergic episode, 44% of participants with anaphylaxis received epinephrine.
• Among those receiving epinephrine, 12% (95% CI, 9% - 14%) required more than 1 dose.

"This finding supports the recommendation that children at risk for food-related anaphylaxis carry 2 doses of self-injectable epinephrine," the study authors write.

Older age and having been transferred from another hospital were risk factors for a subsequent dose.

The study authors noted 3 limitations. First, the use of medical charts may have resulted in the inclusion of inaccurate or incomplete data. Second, the number of patients receiving epinephrine may have been overestimated because of the exclusive focus on ED cases. Finally, the hospital EDs in the study are in an academic, urban setting, possibly resulting in data that may not be nationally representative.

Pediatrics. Published online March 22, 2010.

5. Does diagnosis change as a result of repeat renal colic computed tomography scan in patients with a history of kidney stones?

Adam Goldstone A, et al. Amer J Emerg Med. 2010;28:291-295.

Study objective
We sought to determine the incidence of alternative diagnosis in patients with a history of kidney stones who experience recurrent symptoms and undergo repeat computed tomography (CT) imaging at their return to the emergency department (ED).

Methods
This was a retrospective chart review of ED patients at a tertiary care hospital. Inclusion criteria were all adult ED patients who received a repeat CT for renal colic, after having previously received the diagnosis of obstructive kidney stone confirmed by CT, in our ED. Patients were identified by reviewing the charts of those patients with repeat visits to the ED after January 1, 2004, in which they complained of symptoms suggestive of renal colic and received a CT scan. We determined the frequency of the same diagnosis on repeat CT scan in this population compared with the frequency of alternative diagnosis.

Results
Two hundred thirty-one patients met criteria for the study. Fifty-nine percent were male. One hundred eighty-nine (81.8%) patients had no change in diagnosis as a result of a repeat renal colic CT scan. Twenty-seven (11.6%) patients received an alternative diagnosis that did not require urgent intervention, and 15 (6.5%) patients received a diagnosis that did require an urgent intervention.

Conclusion
Repeat CT imaging of patients with known nephrolithiasis changed management in a minority of patients (6.5%). Knowing the frequency of alternative diagnosis in this population may help clinicians and patients balance the risks and benefits of repeat renal colic CT scans in patients with a history of kidney stones who return to the ED with similar symptoms.

6. Risk for Deep Venous Thrombosis in Patients with Superficial Venous Thrombosis

Among 600 patients with isolated superficial venous thrombosis, 10% experienced thromboembolic events within 3 months.

Decousus H, et al. Ann Intern Med 2010;152:218.

Background: Superficial venous thrombosis (SVT) is perceived to have a benign prognosis.

Objective: To assess the prevalence of venous thromboembolism in patients with SVT and to determine the 3-month incidence of thromboembolic complications.

Design: National cross-sectional and prospective epidemiologic cohort study. (ClinicalTrials.gov registration number: NCT00818688)

Setting: French office- and hospital-based vascular medicine specialists.

Patients: 844 consecutive patients with symptomatic SVT of the lower limbs that was at least 5 cm on compression ultrasonography.

Measurements: Incidence of venous thromboembolism and extension or recurrence of SVT in patients with isolated SVT at presentation.

Results: Among 844 patients with SVT at inclusion (median age, 65 years; 547 women), 210 (24.9%) also had deep venous thrombosis (DVT) or symptomatic pulmonary embolism. Among 600 patients without DVT or pulmonary embolism at inclusion who were eligible for 3-month follow-up, 58 (10.2%) developed thromboembolic complications at 3 months (pulmonary embolism, 3 [0.5%]; DVT, 15 [2.8%]; extension of SVT, 18 [3.3%]; and recurrence of SVT, 10 [1.9%]), despite 540 patients (90.5%) having received anticoagulants. Risk factors for complications at 3 months were male sex, history of DVT or pulmonary embolism, previous cancer, and absence of varicose veins.

Limitation: The findings are from a specialist referral setting, and the study was terminated before the target patient population was reached because of slow recruitment.

Conclusion: A substantial number of patients with SVT exhibit venous thromboembolism at presentation, and some that do not can develop this complication in the subsequent 3 months.

7. Coffee Drinking and Caffeine Associated With Reduced Risk of Hospitalization for Heart Rhythm Disturbances

While it is not proven that coffee is protective, it is unlikely that moderate caffeine intake increases arrhythmia risk, Kaiser Permanente study finds

SAN FRANCISCO — Coffee drinkers may be less likely to be hospitalized for heart rhythm disturbances, according to a new study by the Kaiser Permanente Division of Research in Oakland, Calif. The researchers, who note the findings may be surprising because patients frequently report palpitations after drinking coffee, are presenting the study at the American Heart Association’s 50th Annual Conference on Cardiovascular Disease Epidemiology and Prevention in San Francisco on March 5, 2010.

While it has been established that very large doses of caffeine, the most active ingredient in coffee, can produce rhythm disturbances, there has been limited epidemiologic research about the caffeine doses people take. Previous data from a population study in Denmark compared heavy to light coffee drinkers with respect to risk of atrial fibrillation, the most common major rhythm disturbance, and found no statistically significant difference. This research presentation is believed to be the first large, multiethnic population study to look at all major types of heart rhythm disturbance, the researchers said.

The researchers followed 130,054 men and women and found that those who reported drinking four or more cups of coffee each day had an 18 percent lower risk of hospitalization for heart rhythm disturbances. Those who reported drinking one to three cups each day had a 7 percent reduction in risk, according to Arthur Klatsky, MD, the study’s lead investigator and a senior consultant in cardiology at Kaiser Permanente Division of Research in Oakland, Calif.

“Coffee drinking is related to lower risk of hospitalization for rhythm problems, but the association does not prove cause and effect, or that coffee has a protective effect,” Klasky said. Other explanations for the association might include other traits of coffee drinkers such as exercise or dietary habits. Additionally, some people with heart rhythm problems often are not hospitalized.

“However, these data might be reassuring to people who drink moderate amounts of coffee that their habit is not likely to cause a majorrhythm disturbance,” Klatsky said. While this report is not sufficient evidence to say that people should drink coffee to prevent rhythm problems, it supports the idea that people who are at risk for rhythm problems, or who have rhythm problems, do not necessarily need to abstain from coffee, emphasized Klatsky.

The long-term observational study involved 130,054 men and women, 18 to 90 years old, with the majority less than 50 years old. About 2 percent (3,317) were hospitalized for rhythm disturbances; 50 percent of those were for atrial fibrillation, the most common heart rhythm problem. The 18 percent reduction in risk was consistent among men and women, different ethnic groups, smokers and nonsmokers. It also was similar for various rhythm problems such as paroxysmal supraventricular tachycardia, atrial flutter, and atrial fibrillation.

In the study, 14 percent reported drinking less than one cup of coffee a day; 42 percent reported drinking one to three cups; and 17 percent reported drinking four cups or more each day. Only 27 percent were not coffee drinkers.

While emphasizing that these observational data do not establish causality and a protective mechanism is unclear, researchers speculate that moderate doses of caffeine may affect rhythm disturbances by antagonism of adenosine, a nucleoside compound widely distributed in the body. In the heart adenosine has several effects on conduction of electrical impulses, muscle cell energetics, and heart muscle cell recovery that might predispose to rhythm problems. Caffeine antagonizes adenosine effects by blocking its chemical sites of action.

The researchers examined hospitalization data by elapsed time after the initial examination. For hospitalization within 10 years, the reduction in hospitalizations for people who consumed four cups of coffee or more each day reached 28 percent.

The researchers also studied persons in the group with or without symptoms or history of heart and respiratory disease. For both groups, consuming four cups of coffee daily appeared to be associated with fewer hospitalizations for rhythm disturbances.

For more information on studies related to coffee consumption, go to: http://www.dor.kaiser.org/external/Arthur_Klatsky/

8. Images in Emergency Medicine

Elderly Woman With Abdominal Pain
http://www.annemergmed.com/article/S0196-0644(09)01133-0/fulltext

9. Good and Bad Health Habits in U.S.

Jennifer Warner. March 17, 2010 — Regular drinkers outnumber regular exercisers, says a new report on health behaviors in the U.S.

The CDC study shows that six in 10 American adults were regular drinkers in 2005-2007, but only about three in 10 regularly exercised.

The report details a range of good and bad health habits among American adults, including alcohol use, cigarette smoking, exercise, body weight, and sleep.

Overall, researchers say that since 1997, rates of cigarette smoking have declined by several percentage points, rates of obesity have climbed, and rates of alcohol use, exercise, and sleep have remained relatively unchanged.

The results are based on survey data collected from 79,096 interviews with U.S. adults between 2005-2007 and highlight differences between various gender, ethnic, and social groups when it comes to health behaviors.

Alcohol Use

• Men were more likely than women to be drinkers (68% vs. 55%), and women were more likely than men to abstain from alcohol (31% vs. 18%).
• White people were more likely than African-Americans, Asians, Native Americans, or Alaska Natives to be drinkers.
• The more educated people were, the more likely they were to drink. Seventy-four percent of people interviewed who have a graduate degree were drinkers, compared with 44% of people with a high school diploma.

Cigarette Smoking

• One in five adults were smokers, and more than half (58.5%) had never smoked cigarettes.
• Four in 10 smokers tried to quit smoking in the last year.
• People who hold a GED were more likely than non-high school graduates and high school graduates to be smokers.

Exercise

• About six in 10 adults engaged in at least some leisure-time physical activity, and about three in 10 regularly engaged in some physical activity.
• Adults with higher levels of education were less likely to be smokers, be physically inactive, and be obese and to sleep six hours or less per night.
• Men were more likely than women to be physically active.

Body Weight

• Six in 10 adults were obese or overweight.
• Four in 10 adults were a healthy weight.
• Men were more likely to be overweight (67.9% vs. 53%), but men and women were equally likely to be obese (25.7% vs. 25.0%).

Sleep

• Six in 10 adults usually slept 7 to 8 hours in a 24-hour period.
• Three in 10 adults averaged 6 hours of sleep or fewer per night.
• Men aged 25-44 were more likely than women to sleep 6 hours or fewer, but women aged 65 and older were more likely than men to sleep fewer than 6 hours.

Schoenborn, C. “Health Behaviors of Adults: United States, 2005-2007,” March 17, 2010.

Free full-text (143 pages!): http://www.cdc.gov/nchs/data/series/sr_10/sr10_245.pdf

10. Insurance Companies Refusing Payment for Patients Who Leave the ED Against Medical Advice is a Myth

Wigder HN, et al. Ann Emerg Med. 2010;55:393.

Patients who request to leave emergency departments (EDs) against medical advice are sometimes told by health care providers that their insurance company will not pay their ED visit bill if they leave against medical advice. To test the validity of this assertion, we retrospectively reviewed 104 consecutive cases of patients with insurance leaving against medical advice in 2008 from a suburban level I trauma center that sees 57,000 ED visits per year. Our review included 19 insurance companies, including HMOs, PPOs, Medicare, Medicaid, and workman's compensation. We found that all 104 visits where the patient left against medical advice were fully reimbursed by their respective insurance company. Our review demonstrates that the admonishment by health care providers that insurance companies might not pay for a visit if patients leave the ED against medical advice is not well supported.

The belief that insurers will not reimburse ED visits when patients leave against medical advice is very prevalent among health care providers. We surveyed a convenience sample of 70 ED health care providers (emergency medicine residents and students n=40, attending physicians n=14, nurses n=16). Fifty-seven percent believe that insurance will not pay visits of patients leaving against medical advice. Fifty percent have told or would tell patients that insurance will not pay the bill if you leave against medical advice. Sixty-six percent have heard other health care providers tell patients that insurance will not pay the bill if you leave against medical advice.

In addition, the same belief is held by some consumers. For example, one consumer Web site states the same belief that your insurance company might not pay for the ED visit if you sign out against medical advice.

The problem of patients signing out against medical advice is commonly encountered by many physicians. In a recent study, an estimated 1 in 70 discharges in the United States are against medical advice.

Our study suggests that insurance companies not paying for ED visits of patients leaving against medical advice is a myth. Future studies may elucidate if physicians and nurses tell patients that leaving against medical advice will likely result in nonpayment by insurance to be helpful or to coerce patients to follow their medical recommendations.

11. Management of Early Spontaneous Pregnancy Loss

Procedures for managing early pregnancy loss are moving out of the operating room and into the office, safely and successfully.

Early pregnancy loss (EPL) is common: 15% to 20% of all recognized pregnancies end in spontaneous loss, and about one in four women will experience such pregnancy failure during her lifetime.

Although surgical treatment has been preferred historically, management strategies have evolved to encompass out-of-hospital care. Options for treating women with EPL now include expectant management, medical therapy, and surgical evacuation.

The rest of the (free) article is here: http://womens-health.jwatch.org/cgi/content/full/2010/401/1

12. Rate Control for Atrial Fibrillation: Can We Relax?

In a randomized trial, patients whose heart rates were strictly controlled fared no better than those treated more leniently — at least in the short term.

In many patients with relatively few symptoms, atrial fibrillation (AF) can be managed with heart rate control alone, without rhythm correction. Traditionally, the target in such cases has been the rate that would be expected in a similar patient in sinus rhythm. However, a retrospective analysis of data from two trials of rate versus rhythm control showed no clinical benefit from such strict control. In the current prospective Dutch trial, investigators randomized 614 patients with AF suitable for management with rate control alone to either strict control (below 80 beats/minute at rest and less than 110 beats/minute during moderate exercise) or lenient control (below 110 beats/minute at rest).

At the end of the dose-titration phase of the trial, the mean resting heart rate was markedly different in the strict- and lenient-control groups (76 vs. 93 beats/minute), but by 1 year, the difference had narrowed (75 vs. 86 beats/minute). At 3 years, the composite rate of death, hospitalization for heart failure, stroke, embolization, bleeding, and life-threatening arrhythmia did not differ significantly between the groups.

Comment: This study is the third to show no outcome improvement in patients with atrial fibrillation treated with strict versus lenient rate control. However, these were relatively short-term trials, and remodeling associated with rapid heart rates might not become evident for many more years. Furthermore, even the patients in the lenient-control group achieved reasonably low heart rates. Nonetheless, as an editorialist reminds us, adverse drug effects may outweigh what we believe to be the benefits of strict rate control. It is, indeed, "better to treat the patient and not the electrocardiogram."

— Mark S. Link, MD. Published in Journal Watch Cardiology March 15, 2010. Citation(s):
Van Gelder IC et al. Lenient versus strict rate control in patients with atrial fibrillation. N Engl J Med 2010 Mar 15; [e-pub ahead of print]. Dorian P. Rate control in atrial fibrillation. N Engl J Med 2010 Mar 15; [e-pub ahead of print].

13. Intranasal naloxone delivery is an alternative to intravenous naloxone for opioid overdoses

Merlin MA, et al. Amer J Emerg Med. 2010;28:296-303.

Introduction
This study proposes that intranasal (IN) naloxone administration is preferable to intravenous (IV) naloxone by emergency medical services for opioid overdoses. Our study attempts to establish that IN naloxone is as effective as IV naloxone but without the risk of needle exposure. We also attempt to validate the use of the Glasgow Coma Scale (GCS) in opioid intoxication.

Methods
A retrospective chart review of prehospital advanced life support patients was performed on confirmed opioid overdose patients. Initial and final unassisted respiratory rates (RR) and GCS, recorded by paramedics, were used as indicators of naloxone effectiveness. The median changes in RR and GCS were determined.

Results
Three hundred forty-four patients who received naloxone by paramedics from January 1, 2005, until December 31, 2007, were evaluated. Of confirmed opioid overdoses, change in RR was 6 for the IV group and 4 for the IN group (P = .08). Change in GCS was 4 for the IV group and 3 for the IN group (P = .19). Correlations between RR and GCS for initial, final, and change were significant at the 0.01 level (ρ = 0.577, 0.462, 0.568, respectively).

Conclusion
Intranasal naloxone is statistically as effective as IV naloxone at reversing the effects of opioid overdose. The IV and IN groups had similar average increases in RR and GCS. Based on our results, IN naloxone is a viable alternative to IV naloxone while posing less risk of needle stick injury. Additionally, we demonstrated that GCS is correlated with RR in opioid intoxication.

14. A New Diagnostic Test for Acute Appendicitis?

Preliminary data look promising.

A screening test with high negative predictive value could improve diagnostic accuracy for acute appendicitis and reduce the number of patients needing imaging studies and consultation. In a prospective pilot study, researchers evaluated whether S100A8/A9, a calcium-binding protein that is secreted in inflammatory conditions, is a useful biomarker for acute appendicitis. The study was conducted by the manufacturer of the biomarker assay.

Plasma levels of S100A8/A9 and total white blood cell (WBC) counts were measured in 181 adults and children who presented to three emergency departments with right-sided or infraumbilical acute abdominal pain of less than 2 weeks' duration and no dysuria or recent trauma. The prevalence of acute appendicitis was 23%. For predicting acute appendicitis, S199A8/A9 (at a cutoff of 20 units) had a sensitivity of 93%, specificity of 54%, negative predictive value of 96%, and positive predictive value of 37%. Corresponding values for total WBC count (at a cutoff of 10 to the third power) were 62%, 67%, 86%, and 36%.

Comment: These preliminary data show promise for the S100A8/A9 test in patients with possible acute appendicitis, but the findings of this pilot study must be validated in a prospective trial. This study also shows, yet again, the futility of the outdated and discredited — but surprisingly persistent — practice of using WBC count to diagnose appendicitis.

— Diane M. Birnbaumer, MD, FACEP. Published in Journal Watch Emergency Medicine March 26, 2010. Citation: Bealer JF and Colgin M. S100A8/A9: A potential new diagnostic aid for acute appendicitis. Acad Emerg Med 2010;17:333.

15. Needle tip visualization during ultrasound-guided vascular access: short-axis vs long-axis approach

Stone MB, et al. Amer J Emerg Med. 2010;28:343-347.

Objectives
Ultrasound guidance for central venous catheterization improves success rates and decreases complications when compared to the landmark technique. Prior research has demonstrated that arterial and/or posterior vein wall puncture still occurs despite real-time ultrasound guidance. The inability to maintain visualization of the needle tip may contribute to these complications. This study aims to identify whether long-axis or short-axis approaches to ultrasound-guided vascular access afford improved visibility of the needle tip.

Methods
A prospective trial was conducted at a level I trauma center with an emergency medicine residency. Medical students and residents placed needles into vascular access tissue phantoms using long-axis and short-axis approaches. Ultrasound images obtained at the time of vessel puncture were then reviewed. Primary outcome measures were visibility of the needle tip at the time of puncture and total time to successful puncture of the vessel.

Results
All subjects were able to successfully obtain simulated blood from the tissue phantom. Mean time to puncture was 14.8 seconds in the long-axis group and 12.4 seconds in the short-axis group (P = .48). Needle tip visibility at the time of vessel puncture was higher in the long-axis group (24/39, 62%) as opposed to the short-axis group (9/39, 23%) (P = .01).

Conclusions
In a simulated vascular access model, the long-axis approach to ultrasound-guided vascular access was associated with improved visibility of the needle tip during vessel puncture. This approach may help decrease complications associated with ultrasound-guided central venous catheterization and should be prospectively evaluated in future studies.

See also: Veysman BD. The Vein Teardrop Sign: A Story of Ultrasound-Guided Vascular Access.
J Emerg Med. 2010;38:406-407.

16. Inaccuracies Common in Diagnostic X-Rays for Hip and Pelvic Fractures

Nancy Fowler Larson. March 23, 2010 — Standard X-rays are not a reliable indicator of hip and pelvic fractures, according to an article published in the April issue of the American Journal of Roentgenology.

"Hip fractures cause high morbidity and mortality, especially in the elderly population, in which the 1-year mortality has been reported to be 12-37%," write Matthew Kirby, MD, and Charles Spritzer, MD from the Department of Radiology, Duke University Medical Center, Durham, North Carolina. "The patient population among whom this problem often arises is elderly women with a history of minor trauma."

In a retrospective study, investigators sought to determine the accuracy of hip and pelvic X-rays in patients who arrived at the Duke emergency department with pain or suspected trauma, and who later had a magnetic resonance imaging scan (MRI). The researchers studied the records of 92 patients whose treatment occurred between July 2005 and June 2008. Seventy-seven were women and 15 were men, with an average age of 70.8 years. Sixty-five had a history of trauma, typically a fall or automobile accident.

X-ray Has False Positives and False Negatives

The results showed that X-ray missed a number of fractures and that MRI revealed many fractures undetected by X-ray. Among other findings:

• 13 patients (14%) had 23 fractures (6 hip, 17 pelvic) undetected by X-ray but confirmed by MRI
• 11 patients (12%) whose X-ray suggested the presence of fractures had MRIs that showed none
• 15 patients (16%) with X-rays that did reveal fractures had MRIs that depicted additional breaks missed by X-ray

Of the 59 patients whose MRIs showed no fractures, 43 (73%) had other conditions revealed by MRI, including muscle edema and tears, trochanteric bursitis, and hamstring tendinopathy. An area under the curve of 0.74 was calculated for receiver operating characteristics analysis for hip fracture detection through X-ray.

The researchers concluded that MRI paves the way for better patient care.

"We found a large number of both false-positive and false-negative diagnoses based on radiographic findings alone," the authors write. "Use of MRI has a substantial advantage in the detection of pelvic and femoral fractures, helping to steer patients to appropriate medical and surgical therapy."

Several limitations were noted by the investigators. First, the retrospective study design offers innate limitations, including the fact that work-up bias may have existed, as only patients who underwent MRI were evaluated. Second, no separate examination was done for trauma patients alone. Third, the study included no cost analysis for the added expense of MRI and other factors that might offset it. Finally, variation existed among MRI protocols and requested X-rays.

Future implications for the study include benefits for patients as well as healthcare management, according to the study authors.

"Accurate diagnosis of hip and pelvic fractures in the emergency department can speed patients to surgical management, if needed, and reduce the rate of hospital admissions among patients who do not have fractures," Dr. Spritzer said in a press release. "This distinction is important in terms of health care utilization, overall patient cost, and patient inconvenience."

Duke University Medical Center supported the study. The study authors have disclosed no relevant financial relationships.

AJR Am J Roentgenol. 2010;94:1054-1060.

17. Treating Urinary Tract Infections in Healthy Women — Less Is More

Treatments based on dipstick results are as good as — and less expensive than — those based on culture.

Empirical therapy for urinary tract infections (UTIs) in a primary care setting is effective because most people with symptoms have bacterial infections. Unfortunately, this treatment strategy results in antibiotic prescription for about 10% of the healthy adult female population in the U.K. each year. In four linked studies conducted in southern England, researchers evaluated various approaches to therapy, trying to balance effectiveness with a reduction in unnecessary antibiotic use.

Little and colleagues examined the effectiveness of five strategies commonly used to eliminate UTI symptoms. A total of 309 nonpregnant women aged 18 to 70 were randomized to empirical therapy, begun immediately or delayed by 48 hours, or to targeted antibiotics based on a UTI symptom score, dipstick results (leucocytes, or both nitrites and blood), or culture results from a midstream urine sample. No significant differences were seen among the strategies in time to amelioration of symptoms.

Turner and co-workers evaluated the cost-effectiveness of these five approaches. The dipstick strategy was less costly than urine culture but more costly than empirical therapy. Compared with immediate antibiotics, the dipstick strategy cost about £10 for each day of symptoms avoided. The authors considered only duration of symptoms and cost of care to the National Health Service — not the additional benefit of reducing unnecessary antibiotic use.

Leydon and colleagues used interviews to explore trial participants' views about UTI management. Although the 21 participants generally favored decreasing their exposure to antibiotics, they reacted somewhat more ambiguously to a suggested 48-hour delay in antibiotic therapy. Without careful and caring discussion by the physician, patients who were asked to delay antibiotics were apt to think that their symptoms were not being considered seriously.

Finally, Little and colleagues examined the natural course of uncomplicated UTIs in 839 nonpregnant women aged 18 to 70, of whom 511 had complete symptom diaries and laboratory results. Among patients with infections caused by microbes sensitive to the antibiotic prescribed, severe symptoms lasted an average of 3.32 days. Such symptoms lasted 56% longer in women with resistant organisms (P less than 0.001), 62% longer when no antibiotics were prescribed (P=0.008), and 33% longer in patients with "urethral syndrome" (symptoms, but no laboratory confirmation; P less than 0.001). In multivariate analysis, antibiotic resistance and no antibiotics were the most important factors in prolongation of symptoms.

Comment: These studies, conducted in various private practice settings, suggest that urine culture offers no benefit over empirical therapy in women with uncomplicated UTIs. Although the dipstick strategy is slightly more expensive than empirical therapy, the increased cost may be justified by the reduction in unnecessary antibiotic use. An editorialist notes the need to achieve a balance between individual benefits (alleviation of distress caused by prolonged symptoms, decrease in lost productivity) and population benefits (reduced antibiotic use). The physician's approach to explaining management and allaying fears is an important element in treating women with such infections.

— Stephen G. Baum, MD. Published in Journal Watch Infectious Diseases March 10, 2010. Citation: Little P et al. Effectiveness of five different approaches in management of urinary tract infection: Randomised controlled trial. BMJ 2010; 340:c199.

Full-text: http://www.bmj.com/cgi/content/full/340/feb05_1/c199

18. Emergency Department Workload Increase: Dependence on Primary Care?

Tranquada KE, et al., J Emerg Med. 2010;38:279-285.

Background: Increasing demand for emergency care and crowded emergency departments (EDs) lead some planners to conclude that inconvenient primary care scheduling increases the number of “unnecessary” ED visits. The reasons that the planners argue for more primary care are: to increase funding for primary care; the unfounded notion that it is less expensive to see a primary care physician (PCP) than an Emergency Physician; and the impractical goal that the ED should be used only by intellectually interesting life- or limb-threatened patients or “true emergencies.”

Objective: To explore the rates of patient-reported access to primary care in ambulatory presentations to a rural tertiary care ED.

Methods: An observational study was performed in which an anonymous survey was given to a convenience sample of patients who presented by walking into the ED. Results: Overall, 70.4% (686/975) of respondents stated that they had a PCP, and 38.1 % (252/661) of the sample had attempted to contact their physicians before presenting to the ED. Of the group who attempted to contact their physicians, 62.8% (130) were neither spoken to nor seen by any doctor. These rates did not change by time of presentation or by day of the week.

Conclusion: The results suggest that it is neither a lack of primary care, nor the time of day or night that drives patients to come to the ED.

19. Cardiovascular Benefits of Statins vs. Risk for Incident Diabetes

One additional case of incident diabetes occurred for every 255 patients who received statins for 4 years.

Does statin therapy raise risk for incident diabetes? When statins were compared with placebo (or usual care), mixed signals have emerged, with statins seeming to raise diabetes incidence in some trials and to lower it in others.

In a collaborative meta-analysis, investigators reviewed data from 13 trials in which 90,000 stable nondiabetic patients were randomized to receive a statin or placebo (or usual care) and were followed for a mean of 4 years. The rate of incident diabetes was slightly but significantly higher in patients who took statins than in those who received placebo or usual care (4.9% vs. 4.5%; odds ratio, 1.09). In absolute terms, one additional case of incident diabetes occurred for every 255 patients who received statins for 4 years. No variations in diabetes risk were noted among different statins. The association of statin use and incident diabetes was stronger in trials that involved older patients.

Comment: Although statins might cause one additional case of diabetes per 255 nondiabetic patients treated for 4 years, data from another meta-analysis indicate that statins would prevent five major coronary events in those 255 patients. Therefore, the authors recommend that risk for diabetes should not deter therapy with statins in patients at moderate-to-high cardiovascular risk, but they suggest that older patients who take statins be monitored for hyperglycemia.

— Bruce Soloway, MD. Published in Journal Watch General Medicine March 4, 2010. Citation:
Sattar N et al. Statins and risk of incident diabetes: A collaborative meta-analysis of randomised statin trials. Lancet 2010; 375:735.

20. SCAN Rule May Reduce Misdiagnosis of ICH in Patients with Minor Stroke

Emma Hitt, PhD. March 22, 2010 — A rule involving 4 symptoms — severe hypertension (S), confusion (C), anticoagulation (A), and nausea and vomiting (N) — appears to be specific and sensitive at identifying intracerebral hemorrhage (ICH) in patients with minor stroke.

The SCAN rule states that if at least 1 of these 4 predictive variables is present in a patient with minor stroke, the patient is likely to have ICH. The rule may help determine which patients can be safely treated immediately with antiplatelet agents compared with those who might have ICH and would need further brain imaging (magnetic resonance imaging [MRI] or computed tomography [CT]) before treatment.

Caroline E. Lovelock, MBChB, DPhil, FRACP, formerly with the John Radcliffe Hospital in Oxford, United Kingdom, and now with the Department of Neurology at St. George's Hospital Medical School in London, United Kingdom, and colleagues published their findings in the March issue of Journal of Neurology, Neurosurgery & Psychiatry.

"Because CT brain imaging becomes insensitive to an acute bleed after only a few days, the SCAN rule is particularly useful for identifying which late-presenting patients need priority access to MRI brain imaging so that the risk of misdiagnosing an ICH can be minimized," Dr. Lovelock told Medscape Neurology.

The researchers sought to identify clinical factors associated with ICH in 334 consecutive patients with minor stroke, defined as a National Institutes of Health Stroke Scale score of 3 or less. The predictive model derived in this cohort was then further validated in a separate cohort of 280 patients. Approximately 5% of patients in the initial and validation cohorts had ICH.

"In the hospital clinic validation cohort, at least 1 clinical predictor was present in 24% of patients but in 93% of patients with ICH," the study authors write. "If 2 or more clinical predictors were present, 25% of patients had evidence of ICH on scan."

Data pooled from the derivation and validation cohorts indicated that the SCAN rule had a sensitivity of 97% (95% confidence interval [CI], 84% – 99%) and a specificity of 74% (95% CI, 70% – 77%) for the detection of ICH.

Utility in Various Healthcare Settings

The SCAN rule, which is applicable to late-presenting patients with minor stroke, should be useful in both the US and UK healthcare systems, Dr. Lovelock said. Even in a highly resourced healthcare system, she noted, "patients with minor stroke may still present late to medical attention, particularly if they are relatively socially or geographically isolated."

According to Dr. Lovelock, the SCAN rule may also be useful in poorer countries, "where it can be used to identify which patients with minor stroke need priority access to early CT imaging to rule out ICH," although it still requires validation in different healthcare settings.

Dr. Lovelock noted, though, that the SCAN rule should not be used as an alternative to brain imaging to diagnose ICH. "Instead it is a guide to help plan appropriate investigations and treatment for patients with minor stroke, in whom the possibility of an underlying ICH always needs to be considered."

Not an Alternative to Brain Imaging

According to a related editorial by Enda Kerr and Rustam Al-Shahi Salman with the University of Edinburgh, United Kingdom, "the most useful attribute of the SCAN rule might be its negative predictive value of 99.8% (95% CI, 99% – 100%).

"For the 70% of patients with minor stroke who had a SCAN score of zero, ICH was almost completely ruled out," they point out.

Still, although the SCAN rule almost "rules out ICH in patients with minor strokes and a SCAN score of zero, it is insufficient to completely refute the need for timely and appropriate brain imaging."

Brain imaging can also do more than exclude hemorrhage by identifying the vascular territory of an ischemic stroke, ruling out stroke "mimics" and potentially influencing prognosis estimates or management strategies, they add. "So, where brain imaging facilities permit, immediate brain scanning for all strokes remains the policy that is most cost-effective and results in the greatest gain in quality-adjusted life-years."

Dr. Lovelock, Dr. Kerr, and Dr. Al-Shahi Salman have disclosed no relevant financial relationships. The study used data from the Oxford Vascular Study (OXVASC), which is funded by the UK Medical Research Council, the Dunhill Medical Trust, the Stroke Association, the BUPA Foundation, the National Institute for Health Research (NIHR), the Thames Valley Primary Care Research Partnership, and the NIHR Oxford Biomedical Research Centre.

J Neurol Neurosurg Psychiatry. 2010;81:271-275, 239.

21. ED overcrowding is associated with an increased frequency of medication errors

Kulstad EB, et al. Amer J Emerg Med 2010;28:304-309.

Objectives
Despite the growing problems of emergency department (ED) crowding, the potential impact on the frequency of medication errors occurring in the ED is uncertain. Using a metric to measure ED crowding in real time (the Emergency Department Work Index, or EDWIN, score), we sought to prospectively measure the correlation between the degree of crowding and the frequency of medication errors occurring in our ED as detected by our ED pharmacists.

Methods
We performed a prospective, observational study in a large, community hospital ED of all patients whose medication orders were evaluated by our ED pharmacists for a 3-month period. Our ED pharmacists review the orders of all patients in the ED critical care section and the Chest Pain unit, and all admitted patients boarding in the ED. We measured the Spearman correlation between average daily EDWIN score and number of medication errors detected and determined the score's predictive performance with receiver operating characteristic (ROC) curves.

Results
A total of 283 medication errors were identified by the ED pharmacists over the study period. Errors included giving medications at incorrect doses, frequencies, durations, or routes and giving contraindicated medications. Error frequency showed a positive correlation with daily average EDWIN score (Spearman's ρ = 0.33; P = .001). The area under the ROC curve was 0.67 (95% confidence interval, 0.56-0.78) with failure defined as greater than 1 medication error per day.

Conclusions
We identified an increased frequency of medication errors in our ED with increased crowding as measured with a real-time modified EDWIN score.