Friday, July 31, 2009

Lit Bits: July 31, 2009

From the recent medical literature...

1. Radiographic Pneumonia Uncommon in Children With Wheezing

Laurie Barclay, MD. July 10, 2009 — Because radiographic pneumonia in children with wheezing but without fever is uncommon, the routine use of chest radiography in these children should be discouraged, according to the results of a prospective cohort study reported in the July issue of Pediatrics.

"The diagnosis of pneumonia in children with wheezing can be difficult, because the clinical history and auscultatory findings may be difficult to distinguish from those for children without pneumonia," write Bonnie Mathews, MD, from Children's Hospital Boston and Harvard Medical School in Boston, Massachusetts, and colleagues. "Limited data exist regarding predictors of pneumonia among children with wheezing. The goal was to identify factors associated with radiographically confirmed pneumonia among children with wheezing in the emergency department (ED) setting."

The study sample consisted of 526 individuals not older than 21 years who were seen in the ED, who had wheezing on clinical examination, and who underwent chest radiography because of possible pneumonia. Before learning the chest radiograph results, treating physicians obtained a medical history and performed and recorded a physical examination. Two blinded radiologists independently read the chest radiographs.

Among the included patients, median age was 1.9 years (interquartile range, 0.7 - 4.5 years), 47% had a history of wheezing, 36% were hospitalized, and 4.9% (95% confidence interval [CI], 3.3% - 7.3%) had radiographic pneumonia. Children with wheezing who were afebrile, defined as a temperature of less than 38°C, had a very low rate of pneumonia (2.2%; 95% CI, 1.0% - 4.7%).

Factors linked to an increased risk for radiographic pneumonia were a history of fever at home (positive likelihood ratio [LR], 1.39; 95% CI, 1.13 - 1.70), a history of abdominal pain (positive LR, 2.85; 95% CI, 1.08 - 7.54), triage temperature of 38°C or higher (positive LR, 2.03; 95% CI, 1.34 - 3.07), maximal temperature in the ED of 38°C or higher (positive LR, 1.92; 95% CI, 1.48 - 2.49), and triage oxygen saturation of less than 92% (positive LR, 3.06; 95% CI, 1.15 - 8.16).

Limitations of this study include time constraints, preventing enrollment of all eligible children; reliance on blinded radiologist review; and chest radiographs ordered at the discretion of the physicians caring for the patients, which may have introduced selection bias. The findings are not generalizable to all children with wheezing, and the rate of pneumonia may have been overestimated.

"Radiographic pneumonia among children with wheezing is uncommon," the study authors write. "Historical and clinical factors may be used to determine the need for chest radiography for wheezing children. The routine use of chest radiography for children with wheezing but without fever should be discouraged."

The study authors have disclosed no relevant financial relationships.

Pediatrics. 2009;124:e29-e36.

2. Epilepsy Misdiagnosis Still a Key Reason Behind Long Delays to Identification of Long-QT Syndrome

Shelley Wood. July 31, 2009 (Auckland, New Zealand) — Children and young adults with long-QT syndrome may face long delays before their condition is properly diagnosed, especially if their seizures are misdiagnosed as epilepsy, a new review suggests. Researchers in New Zealand, who published their findings in the July 2009 issue of the Annals of Emergency Medicine, found that the median delay to diagnosis in their series of patients was almost two and a half years, but in some patients lasted more than 20 years.

According to study authors, led by Dr Judith M MacCormick (Starship Children's Hospital, Auckland, New Zealand), mortality in long-QT syndrome is greater than 20% within the first year of a first syncopal event, then rises to nearly 50% after five years. Those numbers, drawn from natural history studies, underscore the importance of making the right diagnosis as swiftly as possible. But as previously reported by heartwire , long-QT is frequently misdiagnosed as epilepsy, particularly in children and young adults, with awareness of the misdiagnosis dating back a quarter century. Since long-QT is also a heritable condition, swift diagnosis could also lead to prevention of sudden death in family members.

"Appropriate intervention can significantly reduce mortality and morbidity, making prompt diagnosis essential," MacCormick and colleagues write.

For their study, they reviewed all cases of long-QT in the New Zealand Cardiac Inherited Disease Registry, identifying 31 people carrying the genetic mutations associated long-QT syndrome. Of these patients, 13 experienced delays ranging from two months to 23 years (median delay 2.4 years) after their first syncope or seizure. If the patient was initially labeled epileptic, the delay to diagnosis was more likely to be longer, a median of 9.75 years (ranging from 7.6 to 20.7 years). During these delays, four sudden unexplained deaths occurred in young relatives of the 31 probands.

Of note, ECGs were not infrequently requested--in 10 of 13 patients--but errors in interpreting the results were common. "Our case series suggests that even when ECGs are undertaken as part of the assessment for syncope and seizure, interpretation is often suboptimal," the authors conclude. This observation is consistent with other recent work suggesting fewer than 40% of noncardiologists and fewer than 50% of cardiologists were able to calculate a QTc interval correctly, they add.

"Our findings show that delayed recognition of long-QT syndrome is still common, with 39% of the patients experiencing delay between initial presentation and diagnosis. Although the results and conclusions of this review are based on a New Zealand cohort, they are likely to be applicable to a wider population, including the United States."

Hoof Beats? Think Zebras

Speaking with heartwire , cardiologist Dr Silvia Priori (University of Pavia, Italy), who was not involved in the study, explained that while misdiagnosis is a known phenomenon in long-QT-syndrome patients, the problem persists in part because of a communication breakdown between the neurologist, the cardiologist, and the patient and his or her family. "This is something that definitely we have known and discussed for some time, but maybe we have not worked out how to best establish this communication with the neurologists," she admitted.

Part of the problem is that many of the patients are just children, in whom a diagnosis of epilepsy seems far more likely that a heart condition.

"The issue in the long-QT community is that in the patient with repeated syncope, especially children, the primary referral is to the neurologist, and epidemiologically this makes sense." The problem, she continued, is that it is not always explained to the family that regardless of the neurological findings, "the appropriate evaluation of syncope and seizure is to see a neurologist and then to see a cardiologist. An ECG should not be denied these patients."

Priori also pointed out that, complicating matters, there are rare but important associations between long-QT and epilepsy.

"If a patient with long-QT has had a cardiac arrest or prolonged hypoxia to the brain, they may have epilepsy as a consequence of brain damage," she noted. "There is also some evidence that, especially, the long-QT type 2 patients may have a form of long-QT that may actually lead to epilepsy. They are not strong data, and it's not very common, but when you talk to people who see a lot of long-QT patients, you find that each of us will have seen one or two families where [several family members] have long-QT and epilepsy together. This is a link that maybe goes beyond coincidence."

3. Randomized, Controlled Trial of Antibiotics in the Management of Community-Acquired Skin Abscesses in the Pediatric Patient

Duong M, et al. Ann Emerg Med. 2009; in press as of July

Study objective
Emergency department visits for skin and soft tissue infections are increasing with the discovery of community-acquired methicillin-resistant Staphylococcus aureus. Whether abscesses treated surgically also require antibiotics is controversial. There are no published pediatric randomized controlled trials evaluating the need for antibiotics in skin abscess management. We determine the benefits of antibiotics in surgically managed pediatric skin abscesses.

This was a double-blind, randomized, controlled trial. Pediatric patients were randomized to receive 10 days of placebo or trimethoprim-sulfamethoxazole after incision and draining. Follow-up consisted of a visit/call at 10 to 14 days and a call at 90 days. Primary outcome was treatment failure at the 10-day follow-up. Secondary outcome was new lesion development at the 10- and 90-day follow-ups. Noninferiority of placebo relative to trimethoprim-sulfamethoxazole for primary and secondary outcomes was assessed.

One hundred sixty-one patients were enrolled, with 12 lost to follow-up. The failure rates were 5.26% (n=4/76) and 4.11% (n=3/73) in the placebo and antibiotic groups, respectively, yielding a difference of 1.15, with a 1-sided 95% confidence interval (CI) (1.15% to 6.8%). Noninferiority was established with an equivalence threshold of 7%. New lesions occurred at the 10-day follow-up: 19 on placebo (26.4%) and 9 on antibiotics (12.9%), yielding a difference of 13.5, with 95% 1-sided CI (13.5% to 24.3%). At the 3-month follow-up, 15 of 52 (28.8%) in the placebo group and 13 of 46 (28.3%) in the antibiotic group developed new lesions. The difference was 0.58, with 95% 1-sided CI (0.5% to 15.6%).

Antibiotics are not required for pediatric skin abscess resolution. Antibiotics may help prevent new lesions in the short term, but further studies are required.

4. Immature WBCs in CSF Do Not Indicate Bacterial Meningitis

In this retrospective study, band forms in CSF of children with meningitis did not predict bacterial etiology.

Meningitis is defined as a cerebrospinal fluid (CSF) white blood cell (WBC) count 10x106/L. Although leukocytosis resulting from any etiology begins with release of immature WBCs ("bands") from the bone marrow, many physicians believe that band forms indicate bacterial infection. To assess whether presence and number of CSF bands predict bacterial etiology, researchers conducted a retrospective chart review of all cases of meningitis diagnosed at eight U.S. pediatric emergency departments from 2001 through 2004. Children who required hospital admission for other reasons and those who were pretreated with antibiotics were excluded.

Of 1116 eligible children, 4% had bacterial meningitis. In multivariate analysis, neither the absolute CSF band count nor the proportion of CSF WBCs accounted for by bands independently predicted bacterial meningitis. The authors noted that CSF and peripheral blood band counts varied widely from center to center and deemed that the variation resulted from interrater variability, rather than clinical reality.

Comment: This study adds to other evidence that band counts are subjective and useless. The authors conclude that "the detection of CSF bands does not seem to be useful for decision making regarding the cause of CSF pleocytosis." At Children’s Hospital Boston, our lab stopped reporting band counts in peripheral blood a few years ago. I hope they’ll do the same with CSF samples. Your lab should, too.

— Daniel J. Pallin, MD, MPH. Published in Journal Watch Emergency Medicine July 10, 2009.
Citation: Kanegaye JT et al. Diagnostic value of immature neutrophils (bands) in the cerebrospinal fluid of children with cerebrospinal fluid pleocytosis. Pediatrics 2009 Jun; 123:e967.

5. Randomized Clinical Trial Comparing a Patient-Driven Titration Protocol of Intravenous Hydromorphone With Traditional Physician-Driven Management of Emergency Department Patients With Acute Severe Pain

Chang AK, et al. Ann Emerg Med. 2009;54:221-225.

Study objective
We test the null hypothesis that the “1+1” hydromorphone patient-driven protocol is clinically and statistically equivalent in safety and efficacy to that of traditional physician-driven administration of opioids for emergency department (ED) treatment of acute severe pain.

This was a prospective randomized clinical trial of nonelderly adults presenting to an urban academic ED with acute pain of sufficient severity to warrant intravenous (IV) opioids in the judgment of the attending physician. Patients randomized to the 1+1 hydromorphone patient-driven protocol received 1 mg IV hydromorphone followed by a second 1-mg dose 15 minutes later if the patient responded affirmatively to the question, “Do you want more pain medication?” Patients in the physician-driven group received any IV opioid in the dose chosen by the ED attending physician, with any additional analgesia provided at the discretion of that physician. The primary outcome was the difference in improvement in pain between the 2 groups at 60 minutes, as measured by a validated and reproducible numeric rating scale. Secondary outcomes included incidence of oxygen desaturation, hypoventilation, hypotension, bradycardia, nausea, vomiting, pruritus, and use of naloxone.

The mean decrease in numeric rating scale pain scores for the 1+1 hydromorphone patient-driven group was 5.6 versus 4.5 in the physician-driven group. The difference of 1.1 numeric rating scale units (95% confidence interval 0.3 to 1.9) was statistically significant but fell 0.2 numeric rating scale units short of the 1.3 numeric rating scale unit threshold required to attain clinically significant efficacy. Safety profiles were similarly satisfactory in both groups. Ninety-four percent of the 1+1 hydromorphone patient-driven group achieved adequate analgesia (as defined by the patient) within 60 minutes of protocol initiation.

The 1+1 hydromorphone patient-driven protocol is statistically superior and at least as clinically efficacious and safe as traditional physician-driven treatment of ED patients with acute severe pain. More than 9 of 10 patients randomized to the study protocol achieved satisfactory pain control, as defined by the patient, within an hour or less.

6. Lidocaine Reduces Pain and Anxiety From Peripheral IV Cannula Insertion

Anthony J. Brown, MD. July 31, 2009 — Injected buffered lidocaine or lidocaine cream can reduce the pain and anxiety associated with intravenous cannula insertion, according to study findings reported in the August issue of the Annals of Emergency Medicine. Between the two, injected lidocaine is more effective in alleviating pain.

Many patients who present to the emergency department require placement of a peripheral IV line, which frequently causes pain and anxiety, Dr. Candace McNaughton, from Vanderbilt University, Nashville, Tennessee, and colleagues note.

Most IV placements in the ER are done without local anesthesia, the researchers point out. This may be due to "time constraints, difficulty with their application, perceived ineffectiveness, a belief that use of local anesthesia makes it more difficult to place IVs, or a belief by healthcare providers that the pain of IV insertion is insignificant."

Research has shown that both the pain and anxiety of IV insertion can be reduced by pretreatment with local anesthetics, but the best method was unclear.

Anesthetic creams are often used to reduce pain during IV insertion. However, in a busy ER setting, their usefulness is limited due to their delayed onset of action, the authors note. By contrast, injected anesthetics have a more rapid onset, but require an additional needle stick.

In a randomized, crossover study, Dr. McNaughton's team compared pain and anxiety in 70 medical students or nurses who had IVs placed after pretreatment with injected buffered lidocaine, lidocaine cream, or no analgesia. A 10-point numeric rating scale was used to assess pain, anxiety, and treatment preference immediately following IV insertion.

The median pain scores with lidocaine cream and injected, buffered lidocaine were 3 and 1, respectively. Without analgesia, the pain was much worse with a median score of 7.

Similarly, the median anxiety score with both lidocaine treatments was 2 compared with a score of 4 without analgesia.

The pretreatment method had no bearing on the likelihood of success, the report indicates, and most of the IV placement attempts were successful.

When surveyed, 70% of the subjects indicated that they would always request injected, buffered lidocaine for themselves and for their patients undergoing IV insertion. Lidocaine cream was the preferred treatment for 26% of subjects and no analgesia for 4%.

Ann Emerg Med. 2009;54:214-220. Abstract:

7. Use of a Urine Dipstick and Brief Clinical Questionnaire to Predict an Abnormal Serum Creatinine in the Emergency Department

Firestone DN, et al. Acad Emerg Med. 2009;16:699-703.

Objectives: Prior data demonstrated that a urine dipstick used alone was a sensitive predictor of abnormal creatinine, but not sufficiently enough to forego screening of serum creatinine prior to administration of contrast for diagnostic studies. The authors hypothesized that a brief historical questionnaire coupled with a urine dipstick would have high sensitivity for renal dysfunction, potentially eliminating the need for a serum creatinine prior to contrast administration.

Methods: This was a prospective study of a convenience sample of patients at two academic tertiary-care emergency departments (EDs) during 2006–2007. Subjects included patients who had both a serum creatinine result reported by the laboratory and a urine dipstick result reported in the medical record. Data included triage vital signs, basic demographic data, 14 medical history items, dipstick urinalysis, and serum creatinine results. The main outcome measure was an abnormal serum creatinine, defined as greater than 1.5 mg/dL.

Results: Complete data sets were collected on 1,354 patient visits. Of these, there were 161 (12%) with a serum creatinine of greater than1.5 mg/dL. Logistic regression analysis identified the following independent predictors associated with elevated creatinine: age greater than 60 years, known renal insufficiency, diabetes, hypertension, diuretic use, vomiting, and proteinuria. Nearly all patients with abnormal creatinine (98%) had at least one of these seven predictors. A decision tool combining these predictors would have identified 158 of 161 patients with an abnormal creatinine (sensitivity, 98.1%; 95% confidence interval [CI] = 95.8% to 99.9%) and a specificity of 21.2% (95% CI = 18.8% to 23.2%).

Conclusions: The absence of six historical factors and absence of proteinuria can be safely used to identify patients who are unlikely to have an abnormal creatinine.

8. Ketamine and Etomidate: Good Choices for RSI in Critically Ill Patients

Mortality rates were similar in patients who received single doses of etomidate or ketamine.

Despite etomidate’s hemodynamic benefits, some clinicians have challenged its use for rapid sequence intubation (RSI) in critically ill patients, citing concerns about adrenal insufficiency (JW Emerg Med Feb 1 2008). In a prospective trial, researchers compared outcomes in 469 adult patients who were randomized to receive a single intravenous bolus of etomidate (0.3 mg/kg) or ketamine (2.0 mg/kg) for induction during RSI at 65 intensive care units (ICUs) and 12 emergency departments or prehospital systems in France. All patients received IV succinylcholine (1 mg/kg) immediately after the trial medication and continuous sedation with midazolam (0.1 mg/kg/hour) combined with fentanyl or sufentanil after tube placement was confirmed.

Final diagnoses were categorized as trauma (22%), sepsis (16%), or other (including stroke, overdose, cardiogenic shock, and acute respiratory failure; 62%). Adrenal insufficiency occurred in significantly more etomidate recipients than ketamine recipients (86% vs. 48%; odds ratio, 6.7). However, no significant differences were noted between groups in maximum sequential organ failure assessment (SOFA) scores during the first 3 days in the ICU (the primary outcome), intubation conditions, various measures of catecholamine use, or 28-day mortality. No drug-related adverse outcomes were reported with either agent. The authors conclude that "ketamine is a safe and valuable alternative to etomidate for intubation in critically ill patients, particularly in septic patients." Editorialists suggest that successful intubation depends on a solid knowledge of pharmacology but do not recommend one agent over the other.

Comment: This elegant and ambitious study demonstrated measurable adrenal suppression but no evidence of adverse outcome related to a single bolus of etomidate for RSI in patients with various types of shock. Adrenal axis suppression is common in critically ill patients; in fact, about half the patients who received ketamine had adrenal insufficiency in this study. The authors note that only 16% of study patients had septic shock, and they call for a larger randomized study that includes more patients with sepsis. Clinicians should choose induction drugs based on individual patient parameters and personal familiarity and not be dissuaded from using either etomidate or ketamine based on concerns that are not supported by evidence.

— Kristi L. Koenig, MD, FACEP. Published in Journal Watch Emergency Medicine July 2, 2009.
Citation: Jabre P et al. Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: A multicentre randomised controlled trial. Lancet 2009 Jul 1; [e-pub ahead of print].

9. CT Scans May Not Be Helpful for Most Young Children With Emergent Headache

Laurie Barclay, MD. July 29, 2009 — Computed tomographic (CT) scans seldom lead to diagnosis or contribute to immediate management of young children presenting to the emergency department with headache but normal neurologic examination findings and nonworrying history, according to the results of a study reported in the July issue of Pediatrics.

"Neuroimaging because of recurrent childhood headaches has limited value; especially in the setting of normal physical examination," write Tarannum M. Lateef, MD, from George Washington University School of Medicine and Children's National Medical Center in Washington, DC, and colleagues. "The risk of radiation exposure from CT scans is highest in the youngest age group. This study addresses the diagnostic utility of CT scans, in an ED [emergency department] setting, for children less than 6 years of age."

The investigators evaluated the records of 364 children aged 2 to 5 years seen between July 1, 2003, and June 30, 2006, in a large urban emergency department for evaluation of headache. Patients with headaches secondary to clearly apparent causes such as ventriculoperitoneal shunts, known brain tumor, or acute illnesses including viral syndromes, fever, probable meningitis, or trauma were identified based on initial history and examination findings. For the remaining patients, headache history, neurologic findings, results of laboratory and neuroimaging tests, discharge diagnosis, and disposition were reviewed.

Among 306 children (84%) with secondary headaches identified from initial history and physical examination, acute febrile illnesses, and viral respiratory tract syndromes were thought to be responsible for the headaches in 72%.

CT scans were performed in 16 (28%) of the 58 children (16% of the total study sample) with no evident central nervous system disease or systemic illness diagnosed at presentation. In 15 (94%) of these 16 patients, CT scans did not facilitate diagnosis or management. Only 1 scan result was abnormal, revealing a brainstem glioma, but this patient had abnormal findings on neurologic examination when first evaluated in the emergency department. Family history was not documented in 59% of children who were thought to have primary headaches.

"For young children presenting to the ED with headache but normal neurologic examination findings and nonworrying history, CT scans seldom lead to diagnosis or contribute to immediate management," the study authors write. "A family history often is contributory and should be part of the evaluation of young children with headache in the ED. CT imaging poses risk (which is greatest for the youngest children), is expensive, and usually is without benefit."

Limitations of this study include retrospective design, lack of complete follow-up monitoring, and analysis limited to information in clinical records. Most children studied did not have a documented family history or a thorough headache history.

"Studies such as this one can contribute to recognition of medical interventions for which indications need rethinking," the study authors conclude.

Pediatrics. 2009;124:e12-e17

10. Images in EM

Female Infant With Fever and Rash

Infant Male With Blood-Colored Stools

Female With Right Lower Quadrant Abdominal Pain

11. Procedural Sedation and Analgesia Outcomes in Children After Discharge From the Emergency Department: Ketamine Versus Fentanyl/Midazolam

McQueen A, et al. Ann Emerg Med. 2009;54:191-197.e4

Study objective
Although the safety and efficacy of procedural sedation and analgesia in the pediatric emergency department (ED) has been established, the prevalence of adverse events after discharge has not been well studied. We compare the postdischarge incidence of adverse behavioral events and vomiting and hypothesize that ketamine would be associated with increased adverse behaviors.

We conducted a prospective observational study of postdischarge behavioral changes and vomiting after sedation with ketamine, ketamine/midazolam, or fentanyl/midazolam. Families were administered a Post Hospital Behavior Questionnaire (PHBQ), with higher scores indicating more adverse behaviors (anxiety, sleep disturbances). We used linear and logistic regression to model PHBQ scores and logistic regression to model vomiting risk adjusting for age, sex, procedure, length of procedure, and parental presence as potential confounders.

Seven hundred eighty-six children were enrolled and 554 children (61% boys; mean age 7.5±4.5 years) were contacted. The prevalence of postdischarge vomiting was 18%, but the prevalence of adverse behavioral changes was low. When adjusted for potential confounders, the odds of a higher PHBQ score increased among patients receiving fentanyl/midazolam (fentanyl/midazolam odds ratio [OR] 2.6, 95% confidence interval [CI] 1.08 to 6.03, P=.03; ketamine OR 1.7, 95% CI 0.84 to 3.57; ketamine/midazolam OR 0.5, 95% CI 0.26 to 1.07).

Procedural sedation and analgesia in the ED is well tolerated. Though postdischarge vomiting occurs with some frequency, there is a low prevalence of adverse behavioral events after discharge. The use of fentanyl/midazolam was associated with higher adverse behavioral scores.

12. Ultrasound Before CT in Patients with Acute Abdominal Pain

A diagnostic strategy of ultrasound followed by CT only if ultrasound results are nondiagnostic optimizes sensitivity while minimizing radiation exposure.

Early diagnostic computed tomography (CT) in patients with acute abdominal pain increases detection of serious diagnoses but is time-consuming and costly and can increase risk for future cancers from radiation exposure (JW Emerg Med Apr 24 2009). To identify an optimal imaging strategy, researchers prospectively collected data for 1021 hemodynamically stable, nonpregnant adult patients (mean age, 47; 55% female) with nontraumatic acute abdominal pain (duration, 2 hours to 5 days) who presented to six emergency departments in the Netherlands. All patients were evaluated by a radiologist with a structured imaging protocol consisting of plain x-rays (upright chest and supine abdomen), ultrasonography, and CT.

At 6 months, an expert physician panel determined the final diagnosis and classified it as urgent (requiring treatment within 24 hours; 65% of patients) or nonurgent. The most common urgent final diagnosis was acute appendicitis (28%), followed by acute diverticulitis (12%). Investigators compared the sensitivity and specificity of 11 diagnostic imaging strategies for detecting conditions classified as urgent. Clinical diagnosis was highly sensitive (88%) but nonspecific, with and without the addition of plain x-rays (specificity, 43% and 41%, respectively). Ultrasound reduced the rate of false-positive urgent diagnoses, but its sensitivity was only 70%. CT had a sensitivity of 89%. Sensitivity was highest (94%) with a conditional strategy of using CT only after nondiagnostic ultrasound; only half the patients would have required CT with this strategy.

Comment: This elegant study provides strong evidence for use of a strategy that optimizes sensitivity while minimizing radiation exposure for evaluation of acute abdominal pain in nonpregnant adults: ultrasound first, followed by CT only if ultrasound results are negative or inconclusive. Of note, intravenous contrast alone was used for CT; thus, CT studies need not be delayed for administration of oral contrast. As shown in many prior studies, plain radiographs are essentially useless, except perhaps to confirm a diagnosis of acute bowel obstruction.

— Kristi L. Koenig, MD, FACEP. Published in Journal Watch Emergency Medicine July 24, 2009. Citation: Laméris W et al. Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: Diagnostic accuracy study. BMJ 2009 Jun 26; 338:b2431. (

13. Comparison of the 20-Hour Intravenous and 72-Hour Oral Acetylcysteine Protocols for the Treatment of Acute Acetaminophen Poisoning

Yarema MC, et al. Ann Emerg Med. 2009; in press.

Study objective
To compare outcomes after acute acetaminophen poisoning in 2 large cohorts of patients treated with either the 20-hour intravenous or 72-hour oral acetylcysteine protocol.

We conducted a retrospective cohort study with historical control comparing patients treated with one of 2 acetylcysteine regimens. Data for the 20-hour group were obtained from a medical record review of patients on whom the 20-hour intravenous protocol was initiated in Canadian hospitals from 1980 to 2005. The 72-hour group consisted of a historical cohort of patients treated in US hospitals with the 72-hour oral protocol from 1976 to 1985. The primary outcome was hepatotoxicity (aminotransferase levels over 1,000 IU/L).

Of the 4,048 patients analyzed, 2,086 were in the 20-hour group and 1,962 were in the 72-hour group. The incidence of hepatotoxicity was 13.9% in the 20-hour group and 15.8% in the 72-hour group (–1.9% absolute difference; 95% confidence interval [CI] -4.2 to 0.3). The relative risk of hepatotoxicity was lower in the 20-hour group when acetylcysteine was initiated within 12 hours of ingestion. The relative risk was lower in the 72-hour group when acetylcysteine was initiated later than 18 hours after ingestion. There was no significant risk difference between groups when acetylcysteine treatment was started 12 to 18 hours after ingestion. One patient in the 20-hour group received a liver transplant and died because of acetaminophen toxicity compared with no liver transplants and 3 deaths in the 72-hour group. Anaphylactoid reactions to intravenous acetylcysteine were reported in 148 of 2,086 patients (7.1%; 95% CI 6.1% to 8.3%). This study is limited by comparison of 2 separate data sets from different countries and study years.

The risk of hepatotoxicity differed between the 20-hour and 72-hour protocols according to the time to initiation of acetylcysteine. It favored the 20-hour protocol for patients presenting early and favored the 72-hour protocol for patients presenting late after acute acetaminophen overdose.

14. Corticosteroids Might Be Beneficial in Severe Sepsis and Septic Shock

Reanalysis of data supports prolonged low-dose treatment in adults.

Annane D, et al. JAMA. 2009;301(22):2362-2375.

Context: The benefit of corticosteroids in severe sepsis and septic shock remains controversial.

Objective: We examined the benefits and risks of corticosteroid treatment in severe sepsis and septic shock and the influence of dose and duration.

Data Sources: We searched the CENTRAL, MEDLINE, EMBASE, and LILACS (through March 2009) databases as well as reference lists of articles and proceedings of major meetings, and we contacted trial authors.

Study Selection: Randomized and quasi-randomized trials of corticosteroids vs placebo or supportive treatment in adult patients with severe sepsis/septic shock per the American College of Chest Physicians/Society of Critical Care Medicine consensus definition were included.

Results: We identified 17 randomized trials (n = 2138) and 3 quasi-randomized trials (n = 246) that had acceptable methodological quality to pool in a meta-analysis. Twenty-eight-day mortality for treated vs control patients was 388/1099 (35.3%) vs 400/1039 (38.5%) in randomized trials (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.71-1.00; P=.05; I2=53% by random-effects model) and 28/121 (23.1%) vs 24/125 (19.2%) in quasi-randomized trials (RR, 1.05, 95% CI, 0.69-1.58; P = .83). In 12 trials investigating prolonged low-dose corticosteroid treatment, 28-day mortality for treated vs control patients was 236/629 (37.5%) vs 264/599 (44%) (RR, 0.84; 95% CI, 0.72-0.97; P = .02). This treatment increased 28-day shock reversal (6 trials; 322/481 [66.9%] vs 276/471 [58.6%]; RR, 1.12; 95% CI, 1.02-1.23; P = .02; I2 = 4%) and reduced intensive care unit length of stay by 4.49 days (8 trials; 95% CI, –7.04 to –1.94; P less than .001; I2 = 0%) without increasing the risk of gastroduodenal bleeding (13 trials; 65/800 [8.1%] vs 56/764 [7.3%]; P = .50; I2 = 0%), superinfection (14 trials; 184/998 [18.4%] vs 170/950 [17.9%]; P = .92; I2 = 8%), or neuromuscular weakness (3 trials; 4/407 [1%] vs 7/404 [1.7%]; P = .58; I2 = 30%). Corticosteroids increased the risk of hyperglycemia (9 trials; 363/703 [51.6%] vs 308/670 [46%]; P less than .001; I2 = 0%) and hypernatremia (3 trials; 127/404 [31.4%] vs 77/401 [19.2%]; P less than .001; I2 = 0%).

Conclusions: Corticosteroid therapy has been used in varied doses for sepsis and related syndromes for more than 50 years, with no clear benefit on mortality. Since 1998, studies have consistently used prolonged low-dose corticosteroid therapy, and analysis of this subgroup suggests a beneficial drug effect on short-term mortality.

15. New CDC Recommendation: All Children Should Receive Annual Seasonal Flu Vaccines

Martha Kerr. July 24, 2009 — The US Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is changing its recommendation for annual seasonal influenza vaccination for children aged 6 months to 18 years to a "full recommendation," Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, announced today.

In addition, the CDC is advising a seasonal flu vaccine for anyone who feels they need one.

"While we are focusing a lot of attention on the 2009 H1N1 influenza virus, we do expect seasonal strains to emerge, and we are issuing updates of which strains to expect," Dr. Schuchat said. These include the A-H1N1, A-H3N2, and B strains, "which are available in this year's vaccine," she noted. "This past year's recommendations encouraged annual vaccination [of children].... This year, [the CDC] is no longer just advising vaccination whenever feasible but is [issuing] a full-out recommendation" of the seasonal flu vaccine.

Only about 40% of the US population received a flu vaccine last year. The CDC is recommending and emphasizing "an intensification of use" of the vaccine.

The CDC has specifically recommended that healthcare workers be immunized, as well as that campers at sleepover summer camps and attendees of military academies where there have been notable outbreaks of influenza receive the flu vaccine and antiviral agents, but only if appropriate.

"I don't think antiviral prophylaxis is a good idea," Dr. Schuchat said, noting that oseltamivir-resistant influenza strains have been reported.

Dr. Schuchat said that the latest laboratory-confirmed case count for the H1N1 influenza virus is 43,771 cases and 302 deaths, "but this is the last time we will be reporting cases in this way." Instead, the CDC will have a FluView Weekly Surveillance Report, updated every Friday, on its Web site.

The National Institutes of Health announced yesterday that clinical trials will begin as early as next week of 2 H1N1 influenza vaccine candidates in adults, either alone or in conjunction with the seasonal flu vaccine and, if safe, in children.

Sanofi Aventis and CSL Biotherapies, manufacturers of the 2 candidate vaccines, told a US Food and Drug Administration (FDA) advisory committee yesterday that they expect to have a vaccine available by October. Dr. Schuchat said that she is concerned that the flu season could be well underway by that time, because the school year begins within weeks in many areas.

The virus is unpredictable, she said, "skipping entire communities, while hitting others really hard." In addition, the virus can cause a wide spectrum of illness, from mild symptoms to respiratory arrest and neurological problems, including seizures. "That is why we are taking the virus so seriously." H1N1 often affects young, apparently healthy individuals, as well as those at high risk, and it could affect more than 40% of the population.

"We are preparing for the worst-case scenario of 60% of the population being affected," Dr. Schuchat said. "The value of worst-case scenario planning is that it allows for continuity planning."

The FDA's Advisory Committee on Immunization Practices is set to meet July 29 to propose H1N1 vaccine recommendations. Children aged 0 to 4 years will likely be the top priority, followed by school-age children, healthcare workers, pregnant women, and adults with chronic diseases.

Today, the FDA announced it had issued an emergency use authorization for a third diagnostic test for the 2009 H1N1 influenza virus because a public health emergency involving H1N1 was declared on April 26, 2009. It is the Focus Diagnostics Influenza H1N1 (2009) Real-Time Reverse Transcription Polymerase Chain Reaction diagnostic test.

The emergency use authorization allows Focus Diagnostics to distribute the test to laboratories certified under the Clinical Laboratory Improvement Amendments to perform high-complexity tests. This test is intended for use in the detection of the 2009 H1N1 influenza virus in patients with symptoms of respiratory infection.

The test does not indicate the stage of infection, nor does a negative result preclude influenza virus infection, FDA officials emphasize.

16. Ultrasonographically Guided Peripheral Intravenous Cannulation in Emergency Department Patients With Difficult Intravenous Access: A Randomized Trial

Stein J, et al. Ann Emerg Med. 2009;54:33-40.

Study objective
We seek to compare ultrasonographically guided peripheral intravenous access to a non–ultrasonographically guided method in a randomized trial of emergency department patients with difficult intravenous access.

A prospective cohort of patients with difficult intravenous access was established. Patients were randomized to 2 groups: (1) intravenous access obtained through an ultrasonographically guided technique or (2) intravenous access obtained through non–ultrasonographically guided methods. Outcomes measured were number of attempts after enrollment, time to cannulation from enrollment, and patient satisfaction. Groups were compared with nonparametric analysis.

Fifty-nine patients were randomized. Twenty-eight patients were randomized to the ultrasonography group and 31 to the no ultrasonography group. A median of 2 further intravenous attempts was required in each group before successful cannulation, corresponding to a difference of 0 attempts (95% confidence interval [CI] 0 to 1 attempts). Time to cannulation showed a median of 39 minutes in the ultrasonography group compared with 26 minutes for the no ultrasonography group, giving a median increase of 13 minutes for the ultrasonographically guided group (95% CI –5 to 28 minutes). Patients in the ultrasonography group had a median Likert satisfaction score of 8 compared with 7 for the no ultrasonography group, giving a median increase of 1 on this scale in the ultrasonography group (95% CI 0 to 2).

Ultrasonographically guided peripheral intravenous cannulation did not decrease the number of attempts or the time to successful catheterization, nor did it improve patient satisfaction compared with the group that did not use ultrasonography. Superiority of ultrasonographically guided peripheral intravenous cannulation is not supported by this study.

17. Nearly One Fifth of Emergency Department Visits Are by the Uninsured

Martha Kerr. July 15, 2009 — US Department of Health and Human Services (HHS) Secretary Kathleen Sebelius released new data today from the Nationwide Emergency Department Sample, the largest all-payer emergency department (ED) database in the country, showing that a disproportionate number of visits were made by uninsured or low-income patients.

There were nearly 120 million ED visits in 2006, according to the HHS's Agency for Healthcare Research and Quality (AHRQ). Nearly one fifth were made by patients without health insurance, Secretary Sebelius said, and one fifth were made by residents of rural areas. One third of ED visits were made by low-income patients.

"Our healthcare system has forced too many uninsured, rural, and low-income Americans to depend on the emergency room for the care they need," Secretary Sebelius said in an HHS release announcing the new findings. "We cannot wait for reform that gives all Americans the high-quality, affordable care they need and helps prevent illnesses from turning into emergencies."

The Nationwide Emergency Department Sample contains 26 million records from ED visits to approximately 1000 community hospitals nationwide, or approximately 20% of all US EDs.

The sample shows national estimates on the number of ED visits to all community hospitals by region, urban vs rural location, teaching status, ownership, and trauma designation. It also contains data on the acute management of patients, including the reason for the visit, the treatments they received, visit outcome (admission, discharge, or transfer to another hospital; death in the ED; or leaving the ED against medical advice). Charges for the visit and who was billed were also recorded.

AHRQ also released the 2007 Nationwide Inpatient Sample today, which is the largest database on hospital care in the United States. HHS officials say it "...provides users with an in-depth look at why patients were hospitalized, the treatments and procedures they received, and what happened to them at discharge. Researchers can use the Nationwide Inpatient Sample to examine trend data as far back as 1988."

The 2007 Nationwide Inpatient Sample contains discharge data from 8 million hospital stays at more than 1000 community hospitals.

18. First-Degree Atrioventricular Block Not as Benign as Previously Thought

Long-term risk for atrial fibrillation, pacemaker placement, and all-cause mortality rose roughly 1.5- to 3-fold.

Cheng S, et al. JAMA. 2009;301(24):2571-2577.

Context: Prolongation of the electrocardiographic PR interval, known as first-degree atrioventricular block when the PR interval exceeds 200 milliseconds, is frequently encountered in clinical practice.

Objective: To determine the clinical significance of PR prolongation in ambulatory individuals.

Design, Setting, and Participants: Prospective, community-based cohort including 7575 individuals from the Framingham Heart Study (mean age, 47 years; 54% women) who underwent routine 12-lead electrocardiography. The study cohort underwent prospective follow-up through 2007 from baseline examinations in 1968-1974. Multivariable-adjusted Cox proportional hazards models were used to examine the associations of PR interval with the incidence of arrhythmic events and death.

Main Outcome Measures: Incident atrial fibrillation (AF), pacemaker implantation, and all-cause mortality.

Results: During follow-up, 481 participants developed AF, 124 required pacemaker implantation, and 1739 died. At the baseline examination, 124 individuals had PR intervals longer than 200 milliseconds. For those with PR intervals longer than 200 milliseconds compared with those with PR intervals of 200 milliseconds or shorter, incidence rates per 10 000 person-years were 140 (95% confidence interval [CI], 95-208) vs 36 (95% CI, 32-39) for AF, 59 (95% CI, 40-87) vs 6 (95% CI, 5-7) for pacemaker implantation, and 334 (95% CI, 260-428) vs 129 (95% CI, 123-135) for all-cause mortality. Corresponding absolute risk increases were 1.04% (AF), 0.53% (pacemaker implantation), and 2.05% (all-cause mortality) per year. In multivariable analyses, each 20-millisecond increment in PR was associated with an adjusted hazard ratio (HR) of 1.11 (95% CI, 1.02-1.22; P = .02) for AF, 1.22 (95% CI, 1.14-1.30; P less than.001) for pacemaker implantation, and 1.08 (95% CI, 1.02-1.13; P = .005) for all-cause mortality. Individuals with first-degree atrioventricular block had a 2-fold adjusted risk of AF (HR, 2.06; 95% CI, 1.36-3.12; P less than .001), 3-fold adjusted risk of pacemaker implantation (HR, 2.89; 95% CI, 1.83-4.57; P less than .001), and 1.4-fold adjusted risk of all-cause mortality (HR, 1.44, 95% CI, 1.09-1.91; P = .01).

Conclusion: Prolongation of the PR interval is associated with increased risks of AF, pacemaker implantation, and all-cause mortality.

19. Ibuprofen Provides Analgesia Equivalent to Acetaminophen–Codeine in the Treatment of Acute Pain in Children with Extremity Injuries: A Randomized Clinical Trial

Friday JH, et al. Acad Emerg Med. 2009;16:711-716.

Objectives: This study compared the analgesic effectiveness of acetaminophen–codeine with that of ibuprofen for children with acute traumatic extremity pain, with the hypothesis that the two medications would demonstrate equivalent reduction in pain scores in an emergency department (ED) setting.

Methods: This was a randomized, double-blinded equivalence trial. Pediatric ED patients 5 to 17 years of age with acute traumatic extremity pain received acetaminophen–codeine (1 mg/kg as codeine, maximum 60 mg) or ibuprofen (10 mg/kg, maximum 400 mg). The patients provided Color Analog Scale (CAS) pain scores at baseline and at 20, 40, and 60 minutes after medication administration. The primary outcome measured was the difference in changes in pain score at 40 minutes, compared to a previously described minimal clinically significant change in pain score of 2 cm. The difference was defined as (change in ibuprofen CAS score from baseline) – (change in acetaminophen–codeine CAS score from baseline); negative values thus favor the ibuprofen group. Additional outcomes included need for rescue medication and adverse effects.

Results: The 32 acetaminophen–codeine and the 34 ibuprofen recipients in our convenience sample had indistinguishable pain scores at baseline. The intergroup differences in pain score change at 20 minutes (−0.6, 95% confidence interval [CI] = −1.5 to 0.3), 40 minutes (−0.4, 95% CI = −1.4 to 0.6), and 60 minutes (0.2, 95% CI = −0.8 to 1.2) were all less than 2 cm. Adverse effects were minimal: vomiting (one patient after acetaminophen–codeine), nausea (one patient after ibuprofen), and pruritus (one after acetaminophen–codeine). The three patients in each group who received rescue medications all had radiographically demonstrated fractures or dislocations.

Conclusions: This study found similar performance of acetaminophen–codeine and ibuprofen in analgesic effectiveness among ED patients aged 5–17 years with acute traumatic extremity pain. Both drugs provided measurable analgesia. Patients tolerated them well, with few treatment failures and minimal adverse effects.

20. Refining the Indications for ERCP in Biliary Pancreatitis

Among patients with severe pancreatitis, only those with cholestasis (bilirubin over 2.3 mg/dL [40 μmol/L] and/or dilated common bile duct) benefited from early ERCP.

van Santvoort HC et al. Ann Surg 2009;250:68-75.


21. Risk of Thromboembolism Varies, Depending on Category of Immobility in Outpatients

Beam DM, et al. Ann Emerg Med. 2009;54:147-152.

Study objective
Immobility predisposes to venous thromboembolism, but this risk may vary, depending on the underlying cause of immobility.

This was a prospective, longitudinal outcome study of self-presenting emergency department (ED) patients who were from 12 hospitals and had suspected venous thromboembolism. Using explicit written criteria, clinicians recorded clinical features of each patient in the ED by using a Web-based data form. The form required one of 6 types of immobility: no immobility, general or whole-body immobility greater than 48 hours, limb (orthopedic) immobility, travel greater than 8 hours causing immobility within the previous 7 days, neurologic paralysis, or other immobility not listed above. Patients were followed for 45 days for outcome of venous thromboembolism, which required positive imaging results and clinical plan to treat. Odds ratios (ORs) were derived from logistic regression including 12 covariates.

From 7,940 patients enrolled, 545 of 7,940 (6.9%) were diagnosed with venous thromboembolism (354 pulmonary embolism, 72 deep venous thrombosis, 119 pulmonary embolism and deep venous thrombosis). Risk of venous thromboembolism varied, depending on immobility type: limb (OR=2.24; 95% confidence interval [CI] 1.40 to 3.60), general (OR=1.76; 95% CI 1.26 to 2.44), other (OR=1.97; 95% CI 1.25 to 3.09), neurologic (OR=2.23; 95% CI 1.01 to 4.92), and travel (OR=1.19; 95% CI 0.85 to 1.67). Other significant risk factors from multivariate analysis included age greater than 50 years (OR =1.5; 95% CI 1.25 to 1.82), unilateral leg swelling (OR=2.68; 95% CI 2.13 to 3.37), previous venous thromboembolism (OR=2.99; 95% CI 2.41 to 3.71), active malignancy (OR=2.23; 95% CI 1.69 to 2.95), and recent surgery (OR=2.12; 95% CI 1.61 to 2.81).

In a large cohort of symptomatic ED patients, risk of venous thromboembolism was substantially increased by presence of limb, whole-body, or neurologic immobility but not by travel greater than 8 hours. These data show the importance of clarifying the cause of immobility in risk assessment of venous thromboembolism.

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