Friday, June 01, 2012

Lit Bits: June 1, 2012

From the recent medical literature... 

1. Prevalence and Factors Associated With False-Positive STEMI Diagnoses at Primary PCI-Capable Centers: A Report From the Activate-SF Registry. 

McCabe JM, et al. Arch Intern Med. 2012 May 7. [Epub ahead of print] 

BACKGROUND: Rapid activation of the cardiac catheterization laboratory for primary percutaneous coronary intervention (PCI) improves outcomes for ST-segment elevation myocardial infarction (STEMI), but selected emphasis on minimizing time to reperfusion may lead to a greater frequency of false-positive activations. 

METHODS: We analyzed consecutive patients referred for primary PCI for a possible STEMI at 2 centers from October 2008 to April 2011. "False-positive STEMI activation" was defined as lack of a culprit lesion by angiography or by assessment of clinical, electrocardiographic, and biomarker data in the absence of angiography. Clinical and electrocardiographic factors associated with false-positive activations were evaluated in a backward stepwise selection bootstrapped logistic regression model. 

RESULTS: Of 411 STEMI activations by emergency physicians, 146 (36%) were deemed to be false-positive activations. Structural heart disease and heart failure were the most common diagnoses among false-positive activations. Electrocardiographic left ventricular hypertrophy (adjusted odds ratio [AOR], 3.15; 95% CI, 1.55-6.40; P = .001), a history of coronary disease (AOR, 1.93; 95% CI, 1.04-3.59; P = .04), or prior illicit drug abuse (AOR, 2.67; 95% CI, 1.13-6.26; P = .02) independently increased the odds of false-positive STEMI activations. Increasing body mass index decreased the odds of a false-positive activation (AOR, 0.91; 95% CI, 0.86-0.97; P = .004), as did angina at presentation (AOR, 0.28; 95% CI, 0.14-0.57; P < .001). 

CONCLUSIONS: More than a third of patients referred for primary PCI from the emergency department did not have a STEMI. Multiple patient-level characteristics were significantly associated with an increased odds of false-positive STEMI activation. 

2. The Use of Cephalosporins in PCN-allergic Patients: A Literature Review Confirms Safety 

Campagna JD, et al. J Emerg Med. 2012;42:612-20. 

Background: The practice of avoiding cephalosporin administration to penicillin-allergic patients persists despite the low rate of cross reactions between both groups of antibiotics. 

Objective: The purpose of this literature review is to evaluate the published evidence regarding the commonly held belief that patients with a history of an allergic reaction to penicillin have a significantly increased risk of an allergic reaction to cephalosporins. 

Materials and Methods: Articles were identified through a computerized search of MEDLINE from 1950 to the present using the search terms “penicillin$,” “cephalosporin$,” “allerg$,” “hypersensitivity,” and “cross-react$.” All articles were reviewed, and additional sources cited in them were added to the literature review. 

Results: Penicillins have a cross allergy with first-generation cephalosporins (odds ratio 4.8; confidence interval 3.7–6.2) and a negligible cross allergy with second-generation cephalosporins (odds ratio 1.1; confidence interval 0.6–2.1). Laboratory and cohort studies confirm that the R1 side chain is responsible for this cross reactivity. Overall cross reactivity between penicillins and cephalosporins is lower than previously reported, though there is a strong association between amoxicillin and ampicillin with first- and second-generation cephalosporins that share a similar R1 side chain. 

Conclusions: Although a myth persists that approximately 10% of patients with a history of penicillin allergy will have an allergic reaction if given a cephalosporin, the overall cross-reactivity rate is approximately 1% when using first-generation cephalosporins or cephalosporins with similar R1 side chains. However, a single study reported the prevalence of cross reactivity with cefadroxil as high as 27%. For penicillin-allergic patients, the use of third- or fourth-generation cephalosporins or cephalosporins with dissimilar side chains than the offending penicillin carries a negligible risk of cross allergy. 

3. Magnesium No Help for Subarachnoid Bleed 

By Todd Neale, Senior Staff Writer, MedPage Today. May 25, 2012 

An infusion of magnesium does not improve outcomes for patients with an aneurysmal subarachnoid hemorrhage, a randomized trial showed. 

The rate of poor functional outcome or death within 3 months of the hemorrhage was 26.2% in the magnesium group and 25.3% in the placebo group (RR 1.03, 95% CI 0.85 to 1.25), according to Sanne Dorhout Mees, MD, of the University Medical Center Utrecht in the Netherlands, and colleagues. 

None of the patient subgroups showed a benefit from the infusion, the researchers reported online in The Lancet. The findings, they wrote, have clinical implications because many centers routinely administer magnesium in this patient population. 

Taking into consideration the results of the current and other trials, "we do not recommend routine use of intravenous magnesium 64 mmol/day for the improvement of outcome after aneurysmal subarachnoid hemorrhage," they wrote. 

Magnesium sulfate is a neuroprotective agent, and smaller trials have evaluated IV magnesium to improve outcomes following aneurysmal subarachnoid hemorrhage, with the thought that the treatment would reduce delayed cerebral ischemia. 

A phase II trial by Dorhout Mees and colleagues showed a 23% relative reduction in the risk of poor outcome with magnesium versus placebo. 

Based on those results, the researchers initiated MASH 2, a phase III trial conducted at six centers in the Netherlands and one each in Scotland and Chile. 

The study included 1,203 adult patients (mean age 57) with an aneurysmal pattern of subarachnoid hemorrhage on brain imaging. All were admitted to the hospital within 4 days of hemorrhage. 

The patients were randomized to IV magnesium sulfate (64 mmol/day) or placebo. Treatment lasted for 20 days after hemorrhage onset or until hospital discharge or death. Patients also were treated according to local protocols, which included oral nimodipine (360 mg/day), bed rest until aneurysm occlusion, and early aneurysm occlusion. 

The primary outcome was a composite of poor functional outcome -- defined as a score of 4 or 5 on the modified Rankin Scale -- or death within 3 months. Magnesium did not reduce that outcome. 

The researchers updated a previous meta-analysis of trials of magnesium treatment for aneurysmal subarachnoid hemorrhage with the results of MASH 2 and found that it, too, showed a lack of benefit (RR 0.96, 95% CI 0.86 to 1.08). 

There were four unexpected serious adverse events during the trial, all in the magnesium group. They included one case of asymptomatic hypocalcemia, two cases of asymptomatic hypermagnesemia, and one case of suspected hypermagnesemia. 

The researchers acknowledged that the study was limited by the lack of quality-of-life assessments and of information on medication adherence. 

In an accompanying editorial, Jose Suarez, MD, and Chethan Venkatasubba Rao, MD, of Baylor College of Medicine in Houston, noted that the trial was the largest to study the use of magnesium sulfate for aneurysmal subarachnoid hemorrhage but did have additional shortcomings. 

The trial lacked an assessment of radiological severity, measurement of underlying systemic severity, information on the rate of delayed cerebral ischemia, and on-site monitoring of the immediate physiological effects of the magnesium infusion, they wrote. 

"Despite these limitations, the results, although disappointing, are nonetheless very pertinent to the management of patients with aneurysmal subarachnoid hemorrhage," the editorialists wrote. "We agree with the researchers, and previous findings, that routine intravenous magnesium sulfate infusion cannot be recommended for patients with aneurysmal subarachnoid hemorrhage." 

4. A Game to Help Doctors Ask Tough Questions on Drug-seeking Behavior 

By Dirk Johnson. New York Times. May 25, 2012 

CHICAGO — As Dr. Danielle McCarthy listens to a man beg for a prescription for painkillers, she weighs her possible responses.  

A 31-year-old emergency room physician, she listens patiently as the man tells her that “every morning I wake up in pain,” describing the agony he continues to endure, three years after being injured in a car wreck.  

He has tried physical therapy, acupuncture and chiropractic treatment, he says. Nothing works except pills, he insists, as his voice grows louder and more demanding.  

Their exchange is similar to conversations that take place on almost every shift at Northwestern Memorial Hospital here, Dr. McCarthy said. But it is fiction — part of an interactive video game designed to train doctors to identify deceptive behavior by people likely to abuse prescription painkillers. The patient is an actor whose statements and responses are generated by the program.

The video game was designed based on research by Dr. Michael F. Fleming at the Northwestern University Feinberg School of Medicine and draws on technology used by the F.B.I. to train agents in interrogation tactics. It teaches doctors to look for warning signs of drug abuse, like a history of family problems, and to observe nonverbal signs of nervousness, like breaking eye contact, fidgeting and finger-tapping.  

The game, which is in its final phase of testing, is aimed at primary care and family doctors, who often feel uncomfortable and unqualified assessing their patients in this regard.  

“This isn’t something medical students have traditionally been trained for,” Dr. Fleming said. “These are hard conversations to have.”  

It can be a thorny matter, Dr. McCarthy said, because physicians are trained to help patients, but they do not want to enable drug abuse. “You don’t want people to be in pain,” she said. “And you’re put on the spot. I’ve had patients yell at me. I’ve never been hit, but once or twice I’ve felt physically threatened.”  

In 2009, for the first time, the number of deaths from drug overdoses surpassed those from highway traffic accidents, according to Gail Hayes, a spokeswoman for the Centers for Disease Control and Prevention. She said misuse of prescription medication has been largely the cause. About 75 percent of overdoses involved prescription drugs, she added.  

So health care professionals are searching for better ways to distinguish patients who can be trusted to use prescription pain medications properly from those out to abuse them. According to the C.D.C., prescription drug abuse is the fastest growing drug problem in the United States, fueled by the use of highly addictive opioid analgesics like OxyContin.  

The Web-based interactive video game, which will soon be available online for a fee to medical schools and health care providers, includes about 2,000 statements by the patient, ranging in tone from charming to irate. A doctor can choose from 1,500 questions and responses, selecting one from five to seven options that appear on the screen when it is time to speak to the patient.  

The dialogue is drawn from research by Dr. Fleming, based on interviews with more than 1,000 patients who were receiving opioids for pain. “We have 95 percent of what a patient and doctor would say or do,” he said.

Sharp skills are needed to assess a patient’s motives, he said, because an objective measurement, like from a blood test or an X-ray, is not available to gauge pain, and the opioids can be highly addictive. 

The game’s software was developed by Dale E. Olsen, a former professor of engineering at Johns Hopkins University. He is the founder and president of Simmersion, a company that has created simulation training programs for the F.B.I. The game’s development was financed by a $1 million grant from the Small Business Administration and the National Institute on Drug Abuse. Dr. Olsen, who has a Ph.D. in statistics, said the game would cost users about $50 an hour. It is designed to be used for 10 sessions of 15 to 20 minutes each. He said customers would most likely include medical schools, as well as private and government health care providers.  

The game encourages doctors to adopt a more collaborative and less accusatory approach with patients, Dr. Olsen said. “The goal is to build rapport,” he said.  

Dr. McCarthy, wearing headphones and blue scrubs, faces the computer screen, where the patient, named Tom, a trim man with a neatly cropped beard, is asking for pain medication.  

The physician asks Tom to describe his pain. Tom points vaguely to his lower back. She asks about whether he has ever had any problems with pills. He acknowledges that he once accidentally took too many pills, but that it was “no big deal.”  

When she asks him to submit to a drug screening, he is testy, but agrees to do so if she insists — “and then I want my pills.”  

At the end of the interactive portion, the game awarded Dr. McCarthy high marks for communication skills, for asking for a drug test and for declining the request for a prescription. She lost points for not asking enough questions.  

Dr. McCarthy nodded at the screen in acknowledgment of her score. She explained that there are time constraints in her work.  

“We move pretty quickly in the emergency room,” she said. “We’re not usually going to have time for 60 questions.”  

She sometimes has had a hunch that a patient was exaggerating or fabricating pain, she said. She found the training useful, she said, because it offered new suggestions of responses to patients. 

5. Applications of minimally invasive cardiac output monitors. 

Porhomayon J, et al. Int J Emerg Med. 2012 Apr 24;5:18. 

Because of the increasing age of the population, critical care and emergency medicine physicians have seen an increased number of critically ill patients over the last decade. Moreover, the trend of hospital closures in the United States t imposes a burden of increased efficiency. Hence, the identification of devices that facilitate accurate but rapid assessments of hemodynamic parameters without the added burden of invasiveness becomes tantamount. The purpose of this review is to understand the applications and limitations of these new technologies. 

The ultimate goal of any hemodynamic monitoring system is to provide the clinicians with additional information on the underlying pathological condition and to guide fluid or vasopressor therapy. Cardiac output measurement and its response to therapeutic interventions are frequently used in critically ill patients. As the use of CO monitoring devices increases today, it is necessary to understand the application of such devices in different clinical settings… 

6. Cricothyroid Membrane Identification by Palpation Is Difficult in Females 

Identification is most difficult in obese female patients.  

Researchers determined the accuracy of identification of the cricothyroid membrane by palpation in females. Each of 24 physicians (17 anesthesiologists and 7 OB/GYN residents) identified the membrane and marked its location and midline in 56 female patients (15 with body-mass index >30 kg/m2) who were in the supine position with their heads in both neutral and extended positions. The actual location was then confirmed by ultrasound. The physician's estimated location was considered correct if it was between the membrane's upper and lower limits and within 5 mm of its midline. 

Physicians correctly identified the location in 0 of 15 obese patients and 10 of 41 nonobese patients in the neutral head position and in 1 obese and 12 nonobese patients in the extended head position. Estimates of the location were as much as 3 cm too high, 4 cm too low, and 1.6 cm off from midline. Physicians considered identification to be more difficult in obese than in nonobese patients (scores of 5.3 vs. 3.3 on a 10-point visual analogue scale). 

Comment: Identification of the cricothyroid membrane is difficult in females, whose laryngeal prominence is less obvious than men's, and is even more difficult in obese patients. The results are not surprising, particularly because the physicians received no additional training in locating the membrane before the study. Although ultrasonography could help to identify the membrane more accurately, prior practice with ultrasonographic landmark identification would be necessary, and time constraints often would prohibit its use. Physicians expected to perform emergency cricothyroidotomy should be trained in the technique and in landmark identification. Use of a vertical midline incision helps correct for imprecise localization of the membrane. 

— Cheryl Lynn Horton, MD. Published in Journal Watch Emergency Medicine May 25, 2012.

Citation: Aslani A et al. Accuracy of identification of the cricothyroid membrane in female subjects using palpation: An observational study. Anesth Analg 2012 May; 114:987. 

7. ED patients with vertigo: can we identify clinical factors associated with acute stroke? 

Chase M, et al. Am J Emerg Med. 2012;30(4):587-91. 

BACKGROUND: Vertigo is a common emergency department (ED) complaint with benign and serious etiologies with overlapping features. Misdiagnosis of acute stroke may result in significant morbidity and mortality. Magnetic resonance imaging (MRI) is superior to computer tomography (CT) for diagnosis of acute stroke but is costly with limited availability. 

OBJECTIVE: The aim of this study was to identify clinical characteristics associated with a cerebrovascular cause for vertigo. 

METHODS: We performed a retrospective chart review on patients with an MRI for vertigo, with or without additional historical or physical examination findings, over 18 months. Study patients were seen in the ED for vertigo within 2 weeks of MRI. Data collected included medical history, physical findings, and imaging results. Fisher's exact test was used to identify factors associated with the primary outcome, an acute stroke. 

RESULTS: There were 325 eligible patients; 131 were ED patients. Patients were 57 (±18) years, and 53% were women. There were 12 ED patients with a new stroke (9.2%). Two variables were associated with acute stroke: a presenting complaint of gait instability (odds ratio, 9.3; 95% confidence interval, 2.6-33.9) or a subtle neurologic finding (odds ratio, 8.7; 95% confidence interval, 2.3-33.1). One patient with a new stroke had a prior stroke, 3 were age >65 years, and none had coronary artery disease or dysrhythmia. Among patients with acute stroke, 5 also had head CT, and none detected the stroke. 

CONCLUSIONS: This study identified 2 variables associated with acute stroke that should be considered in the evaluation of ED patients with vertigo. Head CT was inadequate for diagnosing acute stroke in this patient population. 

8. Reminder: CT is Insensitive for Posterior Circulation Infarcts 

Hwang DY, et al. Comparative Sensitivity of Computed Tomography vs. Magnetic Resonance Imaging for Detecting Acute Posterior Fossa Infarct. J Emerg Med. 2012;42:559-565. 

Background: Posterior fossa strokes, particularly those related to basilar occlusion, pose a high risk for progression and poor neurological outcomes. The clinical history and examination are often not adequately sensitive or specific for detection. 

Study Objectives: Because this population stands to benefit from acute interventions such as intravenous and intra-arterial tissue plasminogen activator, mechanical thrombectomy, and intensive monitoring for neurologic deterioration, this study examined the sensitivity of non-contrast head computed tomography (NCCT) for diagnosing posterior fossa strokes in the emergency department. 

Methods: This study analyzed a prospectively collected database of acute ischemic stroke patients who underwent head NCCT within 30h of symptom onset and who were subsequently found to have a posterior fossa infarct on brain magnetic resonance imaging (MRI) performed within 6h of the NCCT. 

Results: There were 67 patients identified who had restricted diffusion on MRI in the posterior fossa. The National Institutes of Health Stroke Scale (NIHSS) scores ranged from 0 to 36, median 3. Only 28 patients had evidence of infarction on the initial NCCT scan. The timing of NCCT scans ranged from 1.2 to 28.9h after symptom onset. The sensitivity of NCCT was 41.8% (95% confidence interval 30.1–54.4). The longest period of time between symptom onset and a negative NCCT with a subsequent positive diffusion-weighted imaging MRI was 26.7h. 

Conclusions: Head NCCT imaging is frequently insensitive for detecting posterior fossa infarction. Temporal evolution of strokes in this distribution, coupled with beam-hardening artifact, may contribute to this limitation. When a posterior fossa stroke is suspected and the NCCT is non-diagnostic, MRI is the preferred imaging modality to exclude posterior fossa infarction.

9. Concurrent use of warfarin and antibiotics and the risk of bleeding in older adults. 

Baillargeon J, et al. Am J Med. 2012;125(2):183-9. 

BACKGROUND: Antibiotic medications are associated with an increased risk of bleeding among patients receiving warfarin. The recent availability of data from the Medicare Part D prescription drug program provides an opportunity to assess the association of antibiotic medications and the risk of bleeding in a national population of older adults receiving warfarin. 

METHODS: We conducted a case-control study nested within a cohort of 38,762 patients aged 65 years and older who were continuous warfarin users, using enrollment and claims data for a 5% national sample of Medicare beneficiaries with Part D benefits. Cases were defined as patients hospitalized for a primary diagnosis of bleeding and were matched with 3 control subjects on age, race, sex, and indication for warfarin. Logistic regression analysis was used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the risk of bleeding associated with prior exposure to antibiotic medications. 

RESULTS: Exposure to any antibiotic agent within the 15 days of the event/index date was associated with an increased risk of bleeding (aOR 2.01; 95% CI, 1.62-2.50). All 6 specific antibiotic drug classes examined (azole antifungals [aOR, 4.57; 95% CI, 1.90-11.03], macrolides [aOR, 1.86; 95% CI, 1.08-3.21], quinolones [aOR, 1.69; 95% CI, 1.09-2.62], cotrimoxazole [aOR, 2.70; 95% CI, 1.46-5.05], penicillins [aOR, 1.92; 95% CI, 1.21-2.07], and cephalosporins [aOR, 2.45; 95% CI, 1.52-3.95]) were associated with an increased risk of bleeding. 

CONCLUSION: Among older continuous warfarin users, exposure to antibiotic agents-particularly azole antifungals-was associated with an increased risk of bleeding. 

10. Is Urine Odor Associated with UTI in Kids? Sometimes… 

Parental report of malodorous urine was significantly associated with urinary tract infection in young febrile children. 

Gauthier M, et al. Pediatrics. 2012 May;129(5):885-90.  

OBJECTIVE: To determine whether parental reporting of malodorous urine is associated with urinary tract infection (UTI) in children. 

METHODS: We conducted a prospective consecutive cohort study in the emergency department of a pediatric hospital from July 31, 2009 to April 30, 2011. All children aged between 1 and 36 months for whom a urine culture was prescribed for suspected UTI (ie, unexplained fever, irritability, or vomiting) were assessed for eligibility. A standardized questionnaire was administered to the parents by a research assistant. The primary outcome measure was a UTI. 

RESULTS: Three hundred ninety-six children were initially enrolled, but 65 were excluded a posteriori either because a urine culture, although prescribed, was not done (11), was collected by bag (39), and/or showed gross contamination (25). Therefore, 331 children were included in the final analysis. Their median age was 12 months (range, 1-36). Criteria for UTI were fulfilled in 51 (15%). A malodorous urine was reported by parents in 57% of children with UTI and in 32% of children without UTI. On logistic regression, malodorous urine was associated with UTI (odds ratio 2.83, 95% confidence interval: 1.54-5.20). This association remained statistically significant when adjusted for gender and the presence of vesicoureteral reflux (odds ratio 2.73, 95% confidence interval: 1.46-5.08). 

CONCLUSIONS: Parental reporting of malodorous urine increases the probability of UTI among young children being evaluated for suspected UTI. However, this association is not strong enough to definitely rule in or out a diagnosis of UTI. 

11. Stroke Thrombolysis Safe in Eligible Warfarin Users w/ INR ≤ 1.7 

Megan Brooks. May 24, 2012 — Patients with acute ischemic stroke who are receiving warfarin can safely receive intravenous (IV) tissue plasminogen activator (tPA) if their international normalized ratio (INR) is 1.7 or lower, a new study shows. 

With an INR of 1.7 less, "there appears to be no difference in risk of intracranial hemorrhage (ICH) comparing those taking warfarin to those not taking warfarin," lead author Ying Xian, MD, PhD, from the Duke Clinical Research Institute in Durham, North Carolina, told Medscape Medical News. 

He presented the data at the American Heart Association (AHA)/American Stroke Association (ASA) Quality of Care & Outcomes Research 2012 Scientific Sessions in Atlanta, Georgia. 

Support for Guidelines 

This study "provides support for the current INR guideline cut point of 1.7 or less for those on warfarin," Philip B. Gorelick, MD, MPH, medical director of the Hauenstein Neuroscience Center, St. Mary's Health Care in Grand Rapids, Michigan, who was not involved in the study, told Medscape Medical News. 

"Patients undergoing consideration for IV tPA therapy in acute ischemic stroke within a 4.5-hour time window may have taken warfarin at some time proximal to the onset of ischemic stroke," Dr. Gorelick explained. Current guidance suggests that if the INR is 1.7 or lower, IV tPA may be given. 

This INR cut point has been the focus of several case series publications, some of which suggest that this threshold may be safe, "whereas in some patients it has been reported that there may be elevation in the risk of brain hemorrhage with administration of intravenous tPA given this circumstance," Dr. Gorelick noted. 

Dr. Xian's team analyzed data on 23,437 patients with ischemic stroke treated with IV tPA in more than 1200 Get With the Guidelines-Stroke hospitals between April 2009 and June 2011. They performed multivariable logistic regression analysis to evaluate the association of preadmission warfarin use on ICH risk while adjusting for potential confounders. 

At the time of admission and IV tPA administration, 1802 (7.7%) patients were taking warfarin (INR ≤ 1.7). These patients were older (median age, 77 vs 71 years; P < .001) and had more comorbid illness and greater stroke severity (median National Institutes of Health Stroke Scale score, 14 vs 11; P < .001). 

The researchers say crude rates of ICH were higher in warfarin-treated patients (5.7% vs 4.7%); however, after adjustment for numerous potentially confounding factors, ICH risks were similar and these findings were consistent across several sensitivity analyses. 

Among those receiving warfarin, a trend toward higher crude ICH rates was observed among those with higher baseline INR levels (Cochran-Mantel-Haenszel trend test, P = .03). However, after adjustment for risk factors, higher INR levels had only a marginally significant association with ICH risk (adjusted odds ratio, 1.10; 95% confidence interval, 1.00 - 1.20; P = .06 for each 0.1-unit increase in INR). 

This analysis, Dr. Xian and colleagues say, "represents the largest clinical experience" of the safety of thrombolysis in warfarin-treated patients who meet clinical guideline eligibility criteria. 

Dr. Gorelick said, "Although the group data from this study provides some assurance of safety of IV tPA administration in patients who have received warfarin if the INR is ≤1.7, practicing clinicians should note that there still could be some patients with INR ≤1.7 who are at risk of major bleeding." 

"This potential risk should be discussed with the patient and family members though the weight of the GWTGS data suggests that administration of IV tPA under these circumstances may be safe," he added. 

The authors and Dr. Gorelick have disclosed no relevant financial relationships. AHA/ASA Quality of Care & Outcomes Research 2012 Scientific Sessions. Oral Abstract 10. Presented Thursday, May 10, 2012. 

12. Is magnetic resonance safe in implanted cardiac devices patients? 

Cernuschi G, et al. Intern Emerg Med. 2012 Apr 11. [Epub ahead of print] 

Magnetic resonance imaging (MRI) is often avoided in patients with implanted cardiac devices such as pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) because of safety concerns [1]. The overwhelming majority of implanted devices are considered a contraindication to MRI by the U.S. Food and Drug Administration and by devices manufacturers [2]. Exposure to electromagnetic fields could cause variations in sensing, lead impedance and capture threshold. Moreover, it can revert the device to a back-up programming mode known as “power on reset”, during which the device is susceptible to inhibition of pacing output and activation of antitachycardia therapies.  

These alterations together with interference with the ICDs functions may cause adverse clinical events, such as induction of dysrhythmias.  

It is estimated that during their lives, up to 75 % of patients with cardiac devices need an MRI examination… 

Clinical bottom line: With appropriate safety measures and a proper protocol, MRI examinations can be performed safely in patients with selected cardiac devices. Since changes in device variables and programming may occur, electrophysiologic monitoring and strict follow-up are essential. Extrathoracic MRIs seem to be less dangerous than examination involving the body region near the heart. 

13. Intra-abdominal injury rare after a normal abdominal CT scan in adults with blunt trauma 

Holmes JF, et al. Amer J Emerg Med. 2012;30:574-9.  

Objective: The objective of this study is to determine the rate of intra-abdominal injury (IAI) in adults with blunt abdominal trauma after a normal abdominal computed tomographic (CT) scan. We hypothesize that the risk of subsequent IAI is so low that hospital admission and observation for possible IAI are unnecessary. 

Methods: We conducted a prospective, observational cohort study of adults (>18 years) with blunt trauma who underwent abdominal CT scanning in the emergency department. Computed tomographic scans were obtained with intravenous contrast but no oral contrast. Abnormalities on abdominal CT included all visualized IAIs or any finding suggestive of possible IAI. Patients were followed up to determine the presence or absence of IAI and the need for therapeutic intervention if IAI was identified. 

Results: Of the 3103 patients undergoing abdominal CT, 2734 (88%) had normal CT scans. The median age was 39 years (interquartile range, 26-51 years); and 2141 (78%) were admitted to the hospital. Eight (0.3%; 95% confidence interval, 0.1%-0.6%) were identified with IAIs after normal abdominal CT scans including the following injuries: pancreas (5), liver (4), gastrointestinal (2), and spleen (2). Five underwent therapy at laparotomy. Abdominal CT had a likelihood ratio (+) of 20.9 (95% confidence interval, 17.7-24.8) and likelihood ratio (−) of 0.034 (0.017-0.068). 

Conclusion: Adult patients with blunt torso trauma and normal abdominal CT scans are at low risk for subsequently identified IAI. Thus, hospitalization for evaluation of possible IAI after a normal abdominal CT scan is unnecessary in most cases. 

14. Effect of Empirical Treatment with Moxifloxacin and Meropenem vs Meropenem on Sepsis-Related Organ Dysfunction in Patients with Severe Sepsis: A Randomized Trial  

Brunkhorst FM, et al. JAMA 2012. Published online 

Context:  Early appropriate antimicrobial therapy leads to lower mortality rates associated with severe sepsis. The role of empirical combination therapy comprising at least 2 antibiotics of different mechanisms remains controversial. 

Objective:  To compare the effect of moxifloxacin and meropenem with the effect of meropenem alone on sepsis-related organ dysfunction. 

Design, Setting, and Patients:  A randomized, open-label, parallel-group trial of 600 patients who fulfilled criteria for severe sepsis or septic shock (n = 298 for monotherapy and n = 302 for combination therapy). The trial was performed at 44 intensive care units in Germany from October 16, 2007, to March 23, 2010. The number of evaluable patients was 273 in the monotherapy group and 278 in the combination therapy group. 

Interventions:  Intravenous meropenem (1 g every 8 hours) and moxifloxacin (400 mg every 24 hours) or meropenem alone. The intervention was recommended for 7 days and up to a maximum of 14 days after randomization or until discharge from the intensive care unit or death, whichever occurred first. 

Main Outcome Measure:  Degree of organ failure (mean of daily total Sequential Organ Failure Assessment [SOFA] scores over 14 days; score range: 0-24 points with higher scores indicating worse organ failure); secondary outcome: 28-day and 90-day all-cause mortality. Survivors were followed up for 90 days. 

Results:  Among 551 evaluable patients, there was no statistically significant difference in mean SOFA score between the meropenem and moxifloxacin group (8.3 points; 95% CI, 7.8-8.8 points) and the meropenem alone group (7.9 points; 95% CI, 7.5-8.4 points) (P = .36). The rates for 28-day and 90-day mortality also were not statistically significantly different. By day 28, there were 66 deaths (23.9%; 95% CI, 19.0%-29.4%) in the combination therapy group compared with 59 deaths (21.9%; 95% CI, 17.1%-27.4%) in the monotherapy group (P = .58). By day 90, there were 96 deaths (35.3%; 95% CI, 29.6%-41.3%) in the combination therapy group compared with 84 deaths (32.1%; 95% CI, 26.5%-38.1%) in the monotherapy group (P = .43). 

Conclusion:  Among adult patients with severe sepsis, treatment with combined meropenem and moxifloxacin compared with meropenem alone did not result in less organ failure. 

15. When patients do not hurt: silent acute abdomen in a patient with schizophrenia. 

Retamero C, et al. Gen Hosp Psychiatry. 2012 Mar-Apr;34(2):210.e9-11 

Introduction: The phenomenon of pain insensitivity, or hypoalgesia, in schizophrenia and psychotic disorders has been described since the early 20th century [1], [2]. Surgical emergencies such as acute appendicitis are frequently diagnosed late in patients with schizophrenia, and therefore, these individuals suffer from higher rates of surgical complications and death [3].

We present the case of a middle-aged man with schizophrenia who, despite experiencing perforated pyloric ulcers and active gastroduodenal artery bleeding, presented without pain, abdominal rigidity or anorexia… 

[Case not included here.] 

Discussion: Mr. T presented with a painless acute abdomen. The classic, earliest symptom of acute abdomen is pain [4]. In one study of 100 patients with perforated peptic ulcer, 100% presented with complaints of abdominal pain; more than half complained of anorexia, indigestion and/or nausea and approximately 40% had vomiting. Over 75% of patients had a rigid abdomen [5]. In contrast, in a study of 79 psychotic patients, 21.4% of those with acute perforated ulcers and 36.8% of those with acute appendicitis presented without any complaint of pain [6]. Cases of patients with schizophrenia with perforated bowel or acute appendicitis who presented without complaint of pain [7], [8], with pain that appeared late in the course of their illness [9] or with mild, intermittent pain and no abdominal rigidity have also been described [10]. Indeed, the only presenting symptom may be worsening of the patient's psychotic symptoms [9]. This atypical presentation has been shown to result in late diagnosis of the patient's condition and, therefore, in higher rates of morbidity (56% in patients with schizophrenia vs. 16% in the population as a whole) and mortality (4% in patients with schizophrenia vs. 1.8% in the general population) [3]. Moreover, patients with schizophrenia have been found to have increased delirium and confusion in the postoperative period [11]. 

The phenomenon of hypoalgesia in psychotic disorders has long been described but remains poorly understood and has not been verified unequivocally under experimental conditions [12]. In 1911, Bleuler [1] attributed acts of self-mutilation to a “complete analgesia” associated with schizophrenia. Eight years later, Kraepelin [2] noted that patients with schizophrenia were “less sensitive to bodily discomfort.” In 1930, Bender and Schilder [13] observed that patients with schizophrenia exhibit abnormal responses to painful stimuli, such as failure to withdraw or dissociation. Marchand [14], in 1955, evaluating a group of psychotic patients who had suffered acute myocardial infarction found that 85% did not present with pain. In 1958, Goldfarb [15] observed that among a group of children with a diagnosis of schizophrenia, 80% exhibited decreased or no reaction to trauma that ought to have produced tears. Recent experimental studies have demonstrated that pain thresholds are significantly higher in patients with schizophrenia than in healthy controls [16], [17]. 

There are a number of hypotheses that seek to explain pain insensitivity in schizophrenia. Malmo et al. [18] suggested that patients with schizophrenia suffer from a motor deficit that hinders their response to painful stimuli. It has been posited that the use of neuroleptics in psychotic patients might mask pain and contribute to the difficulty of diagnosing medical conditions in this population [7], [8]. A meta-analysis by Potvin and Marchand [19], however, suggests that this phenomenon cannot solely be attributed to the effects of antipsychotic medication. It has been proposed that increased levels of endorphins may account for decreased sensitivity to pain and other symptoms of schizophrenia [20], [21]; however, no correlation between hypoalgesia and levels of endogenous opioids has been found [22]. Recently, Bonnot et al. [23] suggested that the apparent pain insensitivity in schizophrenia is related more to a different mode of pain expression than to a real endogenous analgesia. 

General medical and surgical communities need to be familiarized with the phenomenon of hypoalgesia in psychotic disorders. Physicians should maintain a high index of suspicion for acute abdomen in seriously mentally ill patients who may exhibit diminished or absent perception of pain and may present with unusual signs and symptoms. 

16. Inter-rater Reliability of Sonographic Measurements of the Inferior Vena Cava 

Saul T, et al. J Emerg Med. 2012;42:600-5. 

Background: Bedside ultrasound is emerging as a useful tool in the assessment of intravascular volume status by examining measurements of the inferior vena cava (IVC). Many previous studies do not fully describe their scanning protocol. 

Objectives: The objective of this study was to evaluate which of three commonly reported IVC scanning methods demonstrates the best inter-rater reliability. 

Methods: Three physicians visualized the IVC in three common views and utilized M-mode to measure the maximal and minimal diameter during quiet respiration. Pairwise correlation coefficients were determined using Pearson product-moment correlation. 

Results: The most reliable pair of measurements (inspiratory and expiratory) was found to be using the anterior midaxillary line longitudinal view with a Kappa value for both at 0.692. 

Conclusion: Imaging with the anterior midaxillary longitudinal approach using the liver as an acoustic window provides the best inter-rater reliability when measuring the IVC. Our findings demonstrate that IVC measurements differ based on anatomic location. 

17. ECG Differentiation of Early Repolarization from Subtle Anterior ST-Segment Elevation Myocardial Infarction 

Smith SW, et al. Ann Emerg Med 2012 Apr 18. [Epub ahead of print] 

Study objective: Anterior ST-segment elevation myocardial infarction (STEMI) can be difficult to differentiate from early repolarization on the ECG. We hypothesize that, in addition to ST-segment elevation, T-wave amplitude to R-wave amplitude ratio (T-wave amplitudeavg/R-wave amplitudeavg), and R-wave amplitude in leads V2 to V4, computerized corrected QT interval (QTc) and upward concavity would help to differentiate the 2. We seek to determine which ECG measurements best distinguish STEMI versus early repolarization. 

Methods: This was a retrospective study of patients with anterior STEMI (2003 to 2009) and early repolarization (2003 to 2005) at 2 urban hospitals, one of which (Minneapolis Heart Institute) receives 500 STEMI patients per year. We compared the ECGs of nonobvious (“subtle”) anterior STEMI with emergency department noncardiac chest pain patients with early repolarization. ST-segment elevation at the J point and 60 ms after the J point, T-wave amplitude, R-wave amplitude, QTc, upward concavity, J-wave notching, and T waves in V1 and V6 were measured. Multivariate logistic regression modeling was used to identify ECG measurements independently predictive of STEMI versus early repolarization in a derivation group and was subsequently validated in a separate group. 

Results: Of 355 anterior STEMIs identified, 143 were nonobvious, or subtle, compared with 171 early repolarization ECGs. ST-segment elevation was greater, R-wave amplitude lower, and T-wave amplitudeavg/R-wave amplitudeavg higher in leads V2 to V4 with STEMI versus early repolarization. Computerized QTc was also significantly longer with STEMI versus early repolarization. T-wave amplitude did not differ significantly between the groups, such that the T-wave amplitudeavg/R-wave amplitudeavg difference was entirely due to the difference in R-wave amplitude. An ECG criterion based on 3 measurements (R-wave amplitude in lead V4, ST-segment elevation 60 ms after J-point in lead V3, and QTc) was derived and validated for differentiating STEMI versus early repolarization, such that if the value of the equation ([1.196 x ST-segment elevation 60 ms after the J point in lead V3 in mm]+[0.059 x QTc in ms]–[0.326 x R-wave amplitude in lead V4 in mm]) is greater than 23.4 predicted STEMI and if less than or equal to 23.4, it predicted early repolarization in both groups, with overall sensitivity, specificity, and accuracy of 86% (95% confidence interval [CI] 79, 91), 91% (95% CI 85, 95), and 88% (95% CI 84, 92), respectively, with positive likelihood ratio 9.2 (95% CI 8.5 to 10) and negative likelihood ratio 0.1 (95% CI 0.08 to 0.3). Upward concavity, upright T wave in V1 or T wave, in V1 greater than T wave in V6, and J-wave notching did not provide important information. 

Conclusion: R-wave amplitude is lower, ST-segment elevation greater, and QTc longer for subtle anterior STEMI versus early repolarization. In combination with other clinical data, this derived and validated ECG equation could be an important adjunct in the diagnosis of anterior STEMI. 

18. Red Flags in Electrocardiogram for Emergency Physicians: Remembering Wellens’ Syndrome and Upright T wave in V1 (worth a second posting)

Ünlüer EE, et al. West J Emerg Med. 2012;13:160-162. 

As the electrocardiography (ECG) is a simple, noninvasive tool in the diagnosis and management of coronary artery disease (CAD), emergency physicians (EP) must be proficient in the interpretation of ECGs during evaluation of patients in the emergency department (ED). Sometimes specific T-wave changes for coronary artery disease in precordial ECG derivations may be interpreted as nonspecific T-wave changes by EPs. Failure to diagnose these conditions with subsequent inappropriate management may have fatal consequences. 


A 67-year-old man presented to the ED with anterior chest pain that did not radiate to the neck and left arm. The pain was localized, tight in nature, and had no association with exertion. The patient came from home where the chest pain initiated and was pain free on admission to the ED. His positive cardiac risk factors were smoking and hypertension. The examination was unremarkable. A 12-lead ECG was performed when the patient was free of discomfort and showed normal sinus rhythm with positive T wave in V1, which was greater than T waves in V6 (Figure 1, upper trace). Serum troponin I concentration was 0.03 ng/ml (normal values ,0.04 ng/ml). The patient was admitted to the cardiology service for ECG and cardiac marker follow up. Approximately 4 h later, repeated ECG (Figure 1, lower trace) showed obvious positive T waves in V1 and biphasic T waves in leads V2–3 and negative T waves in V4–5 without chest pain. There were also inverted T waves in lateral leads. Repeated serum troponin I concentration was within the normal range. The electrocardiograph pattern raised the possibility of left anterior descending (LAD) coronary T-wave syndrome. The patient was transferred to another center for cardiac catheterization, which revealed a 95% proximal LAD artery occlusion (Figure 2). The patient underwent emergent percutaneous coronary intervention following coronary angiography with successful outcome. 


19. Use of a limited lights and siren protocol in the prehospital setting vs standard usage 

Merlin MA, et al. Amer J Emerg Med 2012;30:519-525. 

Objective: Our objective was to determine if implementing a standard lights and sirens (L&S) protocol would reduce their use and if this had any effect on patient disposition. 

Methods: In a prospective cohort study, we trained emergency medical services (EMS) personnel from 4 towns in an L&S protocol and enrolled control personnel from 4 addition towns that were not using the protocol. We compare the use of L&S between them over a 6-month period. Our protocol restricted the usage of L&S to patients who had maladies requiring expedited transport. Emergency medical services personnel from the control towns had no such restrictions and were not aware that we were tracking their usage of L&S. We also considered if patient disposition was affected by the judicious usage of L&S. 

Results: Prehospital EMS personnel who were trained in an L&S protocol were 5.6 times less likely to use L&S when compared with those not trained. Of the 808 patients transported by both types of workers, no difference in patient disposition was observed. 

Conclusions: Our protocol significantly reduced the use of L&S. Judicious use of L&S has significant implications for transport safety. By allowing for selective transport with L&S usage, we observed no impact in patient disposition. 

20. t-PA OK for Octogenarians 

By Chris Kaiser, Cardiology Editor, MedPage Today. May 25, 2012 

Recombinant tissue plasminogen activator (rt-PA) works just as well in those older than 80 as it does in younger patients, two studies have found. 

In the randomized Third International Stroke (IST-3) trial, a subgroup analysis of 1,617 patients older than 80 suggested "greater benefit" from thrombolysis in these patients, "contrary to expectations," according to Peter Sandercock, DM, from the University of Edinburgh in Scotland, and colleagues. 

The second study, a meta-analysis that included IST-3, found no difference in the number of events between those older and younger than 80, whether treated with thrombolysis or placebo, reported Joanna M. Wardlaw, MD, also from the University of Edinburgh, and colleagues. 

Both studies were published May 23 online in The Lancet. 

"IST-3 and the updated meta-analysis are an important achievement in stroke research," claimed Didier Leys, MD, and Charlotte Cordonnier, MD, from Roger Salengro Hospital in Lille, France, in an accompanying editorial. 

"Their main strength is the large sample size, allowing subgroup analyses in categories usually excluded from trials, especially elderly patients," they wrote. 

They added, "[T]he role of stroke and emergency physicians is now not to identify patients who will be given rt-PA, but to identify the few who will not." 

Rt-PA is approved in the European Union to treat strokes in patients younger than 80 years, but is not licensed for use in patients over 80. It has been approved in the U.S. since 1996 with no age restrictions. 

The FDA approved rt-PA (alteplase) with the stipulation it be delivered within 3 hours of stroke onset. Guidelines from the American Heart Association/American Stroke Association were updated in 2009 to reflect emerging evidence that rt-PA can be given within 4.5 hours of stroke onset. However, the FDA has not approved this timeline. 

The AHA/ASA guidelines also recommend not giving intravenous rt-PA to patients older than 80. 

"The key message of IST-3 and the updated meta-analysis is that many eligible patients from subgroups excluded by the European licence should now be given rt-PA," Didier and Cordonnier wrote in their editorial. 

IST-3 enrolled 3,035 patients in 156 centers in 12 countries from 2000 to 2011. They were randomized to rt-PA or placebo. 

An early hazard of intracranial hemorrhage and death in the rt-PA group at 7 days evened out at 6 months, where there was no significant difference between the two arms regarding the number of patients who were alive and independent, the primary outcome. 

However, researchers performed an ordinal analysis and found that the rt-PA group had significantly better handicap scores at 6 months (P=0.001). 

Sandercock and colleagues said the 7% fatal or nonfatal symptomatic intracranial hemorrhage rate within 7 days in the rt-PA group was not unexpected, since they "sought to recruit older patients and patients who did not strictly meet prevailing licence criteria for thrombolytic therapy with rt­-PA." 

IST-3 showed that the benefit of thrombolysis was greatest within 3 hours. However, the trial did not have enough power to show any benefit beyond 3 hours. Results also indicated that rt-PA should not be restricted because of the severity of stroke or the presence of early ischemic change on the baseline brain scan, researchers said. 

The meta-analysis by Wardlaw and colleagues of 12 trials (7,012 patients) that compared rt-PA to placebo also revealed that treatment works best within the 3-hour window. However, they suggested that some patients might benefit up to 6 hours after stroke. 

In fact, for every 1,000 patients given thrombolytic therapy up to 6 hours after stroke onset, 42 more patients were alive and independent, and 55 more were alive with a favorable outcome at the end of follow-up. 

Wardlaw and colleagues said that the survival benefit occurred despite the early hazard from intracranial hemorrhage. 

As with IST-3, the meta-analysis showed a benefit from rt-PA despite the severity of stroke and a benefit for those older than 80. 

The investigators suggested that the "small gains in functional ability by 3 to 6 months" could reduce healthcare costs in the long term due to "survival free of disability." 

21. Half of EDs overcrowded, leaders report 

FierceHealthcare May 10, 2012 | By Karen M. Cheung 

Almost half (46 percent) of healthcare leaders say their emergency department (ED) is overcrowded--and 51 percent of those worry it will jeopardize patient safety, according to a HealthLeaders Media report released yesterday. 

In a survey of nearly 300 respondents in operations, clinical work, finance and information, 43 percent of health leaders reported that ED patient flow was their biggest strategic challenge, followed by physician alignment and adherence to quality goals and reimbursement challenges, each at 13 percent. An overwhelming 95 percent said they are working on efforts to improve throughput, including a fast-tracking area for less acute illnesses or injuries (65 percent), a triage medical evaluation process (56 percent), coordination with inpatient floor nurses (55 percent) and a streamlined registration process (54 percent). Only a quarter saw enlarging the ED as a solution to addressing efficiency. 

"We need to examine how we look at the ED and try to find ways to relieve pressure from it that cascades through the hospital systems," Philip A. Newbold, President and CEO of Memorial Hospital & Health System and Elkhart General Healthcare System in South Bend, Ind., said in the report. Newbold said that solutions include express care or around-the-clock urgent care services.  

The report confirms conventional wisdom that the industry is biting its nails over ED overcrowing. As one healthcare leader noted in the report, some patients see the ED as their only care option--whether hospitals like it or not. The report also offers some solutions, such as tending to the most urgent cases first, creating separate areas or freestanding buildings for less acute cases and improving coordination among providers--all with the patient (and experience) in mind.