Tuesday, July 09, 2013

Lit Bits: July 9, 2013

From the recent medical literature...

1. Yield of Routine Provocative Cardiac Testing Among Patients in an ED–Based CP Unit  

Hermann LK, et al. JAMA Intern Med. 2013;173(12):1128-1133.  

Importance  The American Heart Association recommends routine provocative cardiac testing in accelerated diagnostic protocols for coronary ischemia. The diagnostic and therapeutic yield of this approach are unknown. 

Objective  To assess the yield of routine provocative cardiac testing in an emergency department–based chest pain unit. 

Design and Setting  We examined a prospectively collected database of patients evaluated for possible acute coronary syndrome between March 4, 2004, and May 15, 2010, in the emergency department–based chest pain unit of an urban academic tertiary care center. 

Participants  Patients with signs or symptoms of possible acute coronary syndrome and without an ischemic electrocardiography result or a positive biomarker were enrolled in the database. 

Exposures  All patients were evaluated by exercise stress testing or myocardial perfusion imaging. 

Main Outcomes and Measures  Demographic and clinical features, results of routine provocative cardiac testing and angiography, and therapeutic interventions were recorded. Diagnostic yield (true-positive rate) was calculated, and the potential therapeutic yield of invasive therapy was assessed through blinded, structured medical record review using American Heart Association designations (class I, IIa, IIb, or lower) for the potential benefit from percutaneous intervention. 

Results  In total, 4181 patients were enrolled in the study. Chest pain was initially reported in 93.5%, most (73.2%) were at intermediate risk for coronary artery disease, and 37.6% were male. Routine provocative cardiac testing was positive for coronary ischemia in 470 (11.2%), of whom 123 underwent coronary angiography. Obstructive disease was confirmed in 63 of 123 (51.2% true positive), and 28 (0.7% overall) had findings consistent with the potential benefit from revascularization (American Heart Association class I or IIa). 

Conclusions and Relevance  In an emergency department–based chest pain unit, routine provocative cardiac testing generated a small therapeutic yield, new diagnoses of coronary artery disease were uncommon, and false-positive results were common. 

2. Prophylactic Lidocaine after Resuscitation: What's Old Is New Again 

Recurrent cardiac arrest from ventricular fibrillation/ventricular tachycardia was less likely in patients who received lidocaine.  

Years ago, lidocaine was routinely administered for arrhythmia prophylaxis after acute myocardial infarction, but this practice was abandoned after an association with excess mortality was identified. Researchers in King County, Washington (excluding Seattle), retrospectively analyzed data for adult patients with witnessed non-traumatic out-of-hospital cardiac arrest with ventricular fibrillation/ventricular tachycardia (VF/VT) as the initial rhythm, and who had transient or sustained return of spontaneous circulation (ROSC) at any time during resuscitation. Lidocaine was the first-line anti-arrhythmic for treatment of shock-refractory VF/VT; its use for arrhythmia prophylaxis after ROSC was discretionary. 

Of 1721 patients with VF/VT arrest during the 17-year study period, 425 received prophylactic lidocaine after first ROSC. Recurrent VF/VT arrest occurred in significantly fewer lidocaine recipients than non-recipients (16.7% vs. 37.4%). Lidocaine recipients were significantly more likely to survive to hospital admission (93.5% vs. 84.9%) and to hospital discharge (62.4% vs. 44.5%) than non-recipients. There was no evidence of harm associated with post-ROSC lidocaine use. 

Comment: In this study, administration of post-resuscitation prophylactic lidocaine in patients with initial VF/VT cardiac arrest reduced recurrent VF/VT, but this treatment's effect on long-term mortality or neurological status is not clear. Nevertheless, refibrillation has been associated with worsened survival, and this study showed no evidence of harm from lidocaine use — unlike prior studies that showed a possible association with bradycardia and asystole. While intriguing, this study is not a call to change practice but rather suggests that post-arrest lidocaine warrants evaluation in a randomized trial. 

— Kristi L. Koenig, MD, FACEP, FIFEM. Published in Journal Watch Emergency Medicine June 14, 2013. Citation: Kudenchuk PJ et al. Resuscitation 2013 Jun 3; [e-pub ahead of print]. 

3. NAC Plus IV Fluids Versus IV Fluids Alone to Prevent Contrast-Induced Nephropathy in Emergency CT 

Traub SJ, et al. Ann Emerg Med. 2013 June 17. [Epub ahead of print] 

Study objective: We test the hypothesis that N-acetylcysteine plus normal saline solution is more effective than normal saline solution alone in the prevention of contrast-induced nephropathy. 

Methods: The design was a randomized, double blind, 2-center, placebo-controlled interventional trial. Inclusion criteria were patients undergoing chest, abdominal, or pelvic computed tomography (CT) scan with intravenous contrast, older than 18 years, and at least one contrast-induced nephropathy risk factor. Exclusion criteria were end-stage renal disease, pregnancy, N-acetylcysteine allergy, or clinical instability. Intervention for the treatment group was N-acetylcysteine 3 g in 500 mL normal saline solution as an intravenous bolus and then 200 mg/hour (67 mL/hour) for up to 24 hours; and for the placebo group was 500 mL normal saline solution and then 67 mL/hour for up to 24 hours. The primary outcome was contrast-induced nephropathy, defined as an increase in creatinine level of 25% or 0.5 mg/dL, measured 48 to 72 hours after CT. 

Results: The data safety and monitoring board terminated the study early for futility. Of 399 patients enrolled, 357 (89%) completed follow-up and were included. The N-acetylcysteine plus saline solution group contrast-induced nephropathy rate was 14 of 185 (7.6%) versus 12 of 172 (7.0%) in the normal saline solution only group (absolute risk difference 0.6%; 95% confidence interval −4.8% to 6.0%). The contrast-induced nephropathy rate in patients receiving less than 1 L intravenous fluids in the emergency department (ED) was 19 of 147 (12.9%) versus 7 of 210 (3.3%) for greater than 1 L intravenous fluids (difference 9.6%; 95% confidence interval 3.7% to 15.5%), a 69% risk reduction (odds ratio 0.41; 95% confidence interval 0.21 to 0.80) per liter of intravenous fluids. 

Conclusion: We did not find evidence of a benefit for N-acetylcysteine administration to our ED patients undergoing contrast-enhanced CT. However, we did find a significant association between volume of intravenous fluids administered and reduction in contrast-induced nephropathy. 

4. In non-obese patients, duration of action of rocuronium is directly correlated with BMI 

Fujimoto M, et al. Can J Anaesth. 2013 Jun;60(6):552-556. 

BACKGROUND: Administration of neuromuscular blocking agents using a dose calculated on actual body weight carries a risk of prolonged duration of action in obese patients whose body mass index (BMI) is greater than 30 kg·m-2. In the present study, we hypothesized that there could be a correlation between BMI and the duration of action of rocuronium administered according to actual body weight in non-obese patients, in particular, overweight (BMI 25-30 kg·m-2) and underweight patients (BMI below 18.5 kg·m-2). 

METHODS: Sixteen female patients (BMI 15-30 kg·m-2, aged 45-60 yr) scheduled for elective surgery under total intravenous anesthesia were included in this study. Rocuronium 0.9 mg·kg-1 was administered, and adductor pollicis train-of-four responses following ulnar nerve stimulation were monitored every minute with acceleromyography. The times from the injection of rocuronium until spontaneous recovery of first twitch to 5% (5% Duration) and 25% (25% Duration) of baseline were measured, and the correlation with BMI was analyzed. 

RESULTS: A significant correlation between 5% Duration and BMI (r2 = 0.56; P less than 0.001) was found by linear regression analysis. A significant correlation was also found between 25% Duration and BMI (r2 = 0.49; P = 0.003). 

CONCLUSION: In adult female patients with a BMI in the range of 15-30 kg·m-2, the duration of action of rocuronium increases with BMI when the drug is administered on the basis of mg per actual kg body weight. 

5. Are EDs Appropriately Treating Adolescent PID?  

Goyal M, et al. JAMA Pediatr. 2013;167(7):672-673. 

Of the almost 1 million annually diagnosed cases of pelvic inflammatory disease (PID), 20% occur among adolescents.Because reproductive health complaints are the most common reasons for emergency department (ED) visits among adolescent females, it is critical that ED providers are knowledgeable about the diagnosis and treatment of PID. The objective of this study was to evaluate adherence to the Centers for Disease Control and Prevention (CDC) PID treatment guidelines among a nationally representative sample of adolescent ED PID visits. 

We conducted a retrospective cross-sectional analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2000–2009. This study was considered exempt from formal review by our institutional review board. The NHAMCS is an annual, national probability sample survey of hospital EDs conducted by the National Center for Health Statistics branch of the CDC. The eligible study population included all sampled ED visits by females between 14 and 21 years during 2000–2009 with the diagnosis of PID captured by the International Classification of Diseases (ICD-9) codes. Our outcome measure was adherence to CDC recommended PID treatment guidelines by evaluating whether patients were prescribed antibiotics that were considered first or second line treatment for PID for the respective year based on the published CDC Sexually Transmitted Disease treatment guidelines for PID management. Given that the CDC treatment guidelines changed in 2006, we also calculated the average proportion of appropriately treated PID cases before and after the 2006 CDC treatment guideline change. We used descriptive statistics and logistic regression with appropriate weighting to account for the complex survey methodology to calculate all estimates and perform all analyses. 

During the study period, there were an estimated 704,882 (95% CI 571,807, 837,957) PID cases in EDs. Among these, only 37.1% (95% CI 30.6, 45.5) were prescribed antibiotics that adhered to the CDC recommended treatment guidelines. Prior to 2006, only 30.7% (95% CI 9.2, 52.3) of PID cases received appropriate antibiotic therapy. This increased to 49.5% (95% CI 22.9, 76.6%) after the guideline change (p=0.01). The most common antibiotic regimen found among inappropriately treated patients was the combination of ceftriaxone and azithromycin (17.1%). 

This analysis represents the first population-based assessment of recent compliance with CDC recommended treatment guidelines for adolescent ED patients diagnosed with PID. Only 37% of PID cases were treated according to the CDC treatment guidelines in our study. Furthermore, the common use of a third generation cephalosporin and azithromycin suggests that clinicians may erroneously believe that PID treatment is identical to cervicitis treatment and/or that patients are incapable of adherence to doxycycline. This finding has substantial implications as inadequate treatment of PID may lead to serious long-term sequelae such as chronic pelvic pain or tubal infertility. Additionally, the lack of adherence to the CDC guidelines suggests a need to further study strategies for optimal diffusion and acceptance of the CDC guidelines. 

Our finding of low adherence to the CDC treatment guidelines is consistent with those of other single center studies, and studies of adult populations. However, our study is the first to evaluate whether treatment adherence had changed since the dissemination of the CDC 2006 STD treatment guidelines. Even with the sizeable increase in the percent of patients who were treated appropriately from prior to 2006 to afterwards, over 50% of patients are still not receiving treatment consistent with national guidelines. Furthermore, these nationally representative data demonstrate the need and potential high impact of utilizing the ED as a strategic setting to further understand these issues and change clinical practice. 

6. Aggressive Fluid and Sodium Restriction in Acute Decompensated Heart Failure: A RCT  

Aliti GB, et al. JAMA Intern Med. 2013;173(12):1058-1064.  

Importance  The benefits of fluid and sodium restriction in patients hospitalized with acute decompensated heart failure (ADHF) are unclear. 

Objective  To compare the effects of a fluid-restricted (maximum fluid intake, 800 mL/d) and sodium-restricted (maximum dietary intake, 800 mg/d) diet (intervention group [IG]) vs a diet with no such restrictions (control group [CG]) on weight loss and clinical stability during a 3-day period in patients hospitalized with ADHF. 

Design  Randomized, parallel-group clinical trial with blinded outcome assessments. 

Setting  Emergency room, wards, and intensive care unit. 

Participants  Adult inpatients with ADHF, systolic dysfunction, and a length of stay of 36 hours or less. 

Intervention  Fluid restriction (maximum fluid intake, 800 mL/d) and additional sodium restriction (maximum dietary intake, 800 mg/d) were carried out until the seventh hospital day or, in patients whose length of stay was less than 7 days, until discharge. The CG received a standard hospital diet, with liberal fluid and sodium intake. 

Main Outcomes and Measures  Weight loss and clinical stability at 3-day assessment, daily perception of thirst, and readmissions within 30 days. 

Results  Seventy-five patients were enrolled (IG, 38; CG, 37). Most were male; ischemic heart disease was the predominant cause of heart failure (17 patients [23%]), and the mean (SD) left ventricular ejection fraction was 26% (8.7%). The groups were homogeneous in terms of baseline characteristics. Weight loss was similar in both groups (between-group difference in variation of 0.25 kg [95% CI, −1.95 to 2.45]; P = .82) as well as change in clinical congestion score (between-group difference in variation of 0.59 points [95% CI, −2.21 to 1.03]; P = .47) at 3 days. Thirst was significantly worse in the IG (5.1 [2.9]) than the CG (3.44 [2.0]) at the end of the study period (between-group difference, 1.66 points; time × group interaction; P = .01). There were no significant between-group differences in the readmission rate at 30 days (IG, 11 patients [29%]; CG, 7 patients [19%]; P = .41). 

Conclusions and Relevance  Aggressive fluid and sodium restriction has no effect on weight loss or clinical stability at 3 days and is associated with a significant increase in perceived thirst. We conclude that sodium and water restriction in patients admitted for ADHF are unnecessary. 

7. Re-Evaluating the Diagnostic Accuracy of the Tongue Blade Test: Still Useful as a Screening Tool for Mandibular Fractures? Yes! 

Caputo ND, et al. J Emerg Med. 2013;45:8-12.   

Background: Mandibular fractures are one of the most frequently seen injuries in trauma. In terms of facial trauma, mandible fractures constitute 40%–62% of all facial bone fractures. The tongue blade test (TBT) has been shown to be a sensitive screening tool when compared with plain films. However, recent studies have demonstrated that computed tomography (CT) scan is more sensitive for determining mandible fractures than the traditionally used plain films. 

Objective: The purpose of the study was to determine the sensitivity and specificity of the TBT as compared with the new gold standard of radiologic imaging, CT scan. 

Methods: Any patient suffering from facial trauma was prospectively enrolled during the study period (August 1, 2010 to April 11, 2012) at a single urban, academic Emergency Department. A TBT was performed by the resident physician and confirmed by the supervising attending. CT facial bones were then obtained for the ultimate diagnosis. Inter-rater reliability (κ) was calculated, along with sensitivity, specificity, negative predictive value, and likelihood ratio (–) based on a 2 × 2 contingency table generated. 

Results: During the study period, 190 patients were enrolled. Inter-rater reliability was κ = 0.96 (95% confidence interval [CI] 0.93–0.99). The following parameters were then calculated based on the contingency table: sensitivity 0.95 (95% CI 0.88–0.98), specificity 0.68 (95% CI 0.57–0.77), negative predictive value 0.92 (95% CI 0.82–0.97), and likelihood ratio (−) 0.07 (95% CI 0.03–0.18). 

Conclusions: Based on the test characteristics calculated (negative predictive value 0.92, sensitivity 0.95, likelihood ratio −0.07), the TBT is a useful screening tool to determine the need for radiologic imaging. 

8. "Proning" Benefits Patients with Severe ARDS 

 Acute respiratory distress syndrome–associated 28-day mortality was halved in patients who spent most of the day face down.  

Patients with acute respiratory distress syndrome (ARDS) commonly develop consolidation of the dependent lung regions. For many years, physicians have transitioned severely hypoxemic patients from supine to prone position to improve aeration of these areas and gas exchange. Small studies of "proning" demonstrated improved oxygenation without affecting more important outcomes; meta-analyses suggested proning could lower ARDS-associated mortality (Intensive Care Med 2010; 36:585).

This large French trial involved 466 patients with moderate-to-severe ARDS (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen [PaO2:FiO2] less than 150, with FiO2 ≥0.6; positive end-expiratory pressure, ≥5 cm H2O). All patients received low tidal-volume ventilation and were randomized to daily prone positioning or to supine positioning only. Intervention patients were placed in the prone position within 1 hour of randomization and underwent an average of four sessions of proning (mean duration per daily session, 17.3 hours). At randomization, greater than 80% of patients were receiving neuromuscular blockade, and approximately 40% were receiving glucocorticoids. Mortality at 28 days was 16% in the prone group and 33% in the supine group. 

Comment: These results give new life to the practice of proning. Although this intervention is not suitable for all patients with acute respiratory distress syndrome (e.g., those with recent sternotomy or facial trauma), proning should be considered early for most patients with severe disease. Almost all patients in this study received neuromuscular blockade, which reinforces earlier administering of short-term paralytics for severe hypoxemia. Patients in this study were proned for prolonged periods. Delivering care safely to patients in this position for most of the day will require additional training of nurses and other providers. 

— Patricia Kritek, MD. Two videos that illustrate proning have been published with this article and are available to New England Journal of Medicine subscribers through the link given in the citation. Published in Journal Watch General Medicine June 13, 2013. Citation: Guérin C et al. N Engl J Med 2013 Jun 6; 368:2159. 

9. Images in Clinical Medicine 

Hand Pain After Fall

That's Not An Abscess!

Eyelid Swelling and Primary Sjögren's Syndrome

Sudden Unilateral Corneal Clouding in an Infant

10. Sharp Increase in ED Visits for Mental Health Disorders 

Visits related to mental health disorders increased at three times the rate of ED visits overall. 

Hakenewerth AM, et al. Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep 2013 Jun 14.     

Results (excerpt):
From 2008 to 2010, the annual number of ED visits in North Carolina increased by 5.1%, from 4,190,911 to 4,405,676, and Mental Health Disorders Diagnostic Code (MHD-DC)-related ED visits increased by 17.7%, from 347,806 to 409,276 (Table 1). By 2010, ED visits with MHD-DCs accounted for 9.3% of all ED visits; 31.1% of ED visits with MHC-DCs resulted in hospital admission, compared with 14.1% of all ED visits. 

11. Electrolyte Abnormalities in Children with Hypertrophic Pyloric Stenosis  

Most children with hypertrophic pyloric stenosis had normal serum electrolytes at time of diagnosis.  

Tutay GJ et al. Pediatr Emerg Care 2013; 29:465 

OBJECTIVES: Recent investigations have demonstrated that the classic hypochloremic, hypokalemic, metabolic alkalosis of hypertrophic pyloric stenosis (HPS) is not a common finding.Some have suggested a trend over time, but none has investigated factors contributing to laboratory derangement, such as duration of vomiting or patient age at presentation. We sought to determine the proportion of patients with HPS with normal and abnormal laboratory findings as a function of year of presentation, duration of vomiting, and patient age. 

METHODS: This is a retrospective chart review of 205 patients younger than 6 months with operative diagnosis of HPS at a tertiary, regional pediatric center from 2000 to 2009. We examined the acid-base status and electrolyte levels (serum bicarbonate [CO2], serum potassium [K], and serum chloride [Cl]) at the time of the index visit to determine the proportion of normal, high, and low values for each as a function of year of presentation, duration of vomiting, and patient age. 

RESULTS: The proportion of HPS cases with normal CO2 was 62%; low serum CO2, 20%; and high CO2, 18%. The proportion with normal serum K was 57%; low K, 8%; and high K, 35%. The proportion with normal Cl was 69%; low Cl, 25%; and high Cl, 6%. Logistic regression analysis demonstrated that the prevalence of metabolic alkalosis increased across the decade, whereas the prevalence of metabolic acidosis decreased and that advancing age was associated with the presence of alkalosis. 

CONCLUSIONS: We observed that normal laboratory values are the most common finding in HPS and that metabolic alkalosis was found more commonly in the latter part of the decade and in older infants. 

12. Continuous neuromuscular blockade is associated with decreased mortality in post-cardiac arrest patients. 

Salciccioli JD, et al. Resuscitation. 2013 Jun 21. pii: S0300-9572(13)00331-6. doi: 10.1016/j.resuscitation.2013.06.008. [Epub ahead of print] 

AIM: Neuromuscular blockade may improve outcome in patients with acute respiratory distress syndrome. In post-cardiac arrest patients receiving therapeutic hypothermia, neuromuscular blockade is often used to prevent shivering. Our objective was to determine whether neuromuscular blockade is associated with improved outcomes after out-of-hospital cardiac arrest. 

METHODS: A post hoc analysis of a prospective observational study of comatose adult (over 18 years) out-of-hospital cardiac arrest at 4 tertiary cardiac arrest centers. The primary exposure of interest was neuromuscular blockade for 24h following return of spontaneous circulation and primary outcomes were in-hospital survival and neurologically intact survival. Secondary outcomes were evolution of oxygenation (PaO2:FiO2), and change in lactate. We tested the primary outcomes of in-hospital survival and neurologically intact survival with multivariable logistic regression. Secondary outcomes were tested with multivariable linear mixed-models. 

RESULTS: A total of 111 patients were analyzed. In patients with 24h of sustained neuromuscular blockade, the crude survival rate was 14/18 (78%) compared to 38/93 (41%) in patients without sustained neuromuscular blockade (p=0.004). After multivariable adjustment, neuromuscular blockade was associated with survival (adjusted OR: 7.23, 95% CI: 1.56-33.38). There was a trend toward improved functional outcome with neuromuscular blockade (50% versus 28%; p=0.07). Sustained neuromuscular blockade was associated with improved lactate clearance (adjusted p=0.01). 

CONCLUSIONS: We found that early neuromuscular blockade for a 24-h period is associated with an increased probability of survival. Secondarily, we found that early, sustained neuromuscular blockade is associated with improved lactate clearance. 

13. Value of Emergency Medicine: ACEP’s “Saving Millions” PR Campaign  

ACEP NEWS, 06/13/13 

In addition to a press release issued at last month’s Leadership and Advocacy Conference to highlight the RAND Corporation study, ACEP launched a public relations campaign to highlight the value of emergency medicine. The theme is "Saving Millions." The campaign is built around many of the following key points: 

• Four in five people who called their family doctors about a sudden medical issue got the same advice: Go to the emergency department (RAND report) 

• Primary care physicians increasingly depend on EDs to see their patients after hours, perform complex diagnostic workups, and facilitate admissions of acutely ill patients (RAND report) 

• Emergency physicians provide a disproportionate share of acute health care on weekends, holidays and after regular business hours (CDC)

• Ninety-two percent of patients who visit the emergency department each year have the same condition – a real medical emergency (CDC) 

• According to the RAND Report, the 4 percent of America’s doctors who staff hospital emergency departments provide/manage 11 percent of all outpatient care in the United States, 28 percent of all acute care visits, half of the acute care visits by Medicaid and CHIP beneficiaries and two-thirds of all acute care for the uninsured 

• Emergency physicians can save money in the health care system because they are key decision-makers in more than half of hospital admissions 

• Hospital admissions from the emergency department increased by 17 percent over 7 years (RAND) 

• Emergency physicians coordinate transitions of care every day in hospitals across the country, filling the gaping holes in our health care system 

• Lack of access to follow-up care is a top concern that influences a physician’s decision to admit patients to the hospital (RAND)  

14. New Guidelines on tPA in Stroke: Putting Out Fires With Gasoline? 

Millard WB, et al. Ann Emerg Med. 2013;62:A13-A18 


When a joint panel representing the American College of Emergency Physicians (ACEP) and the American Academy of Neurology (AAN) issued guidelines1 on the use of recombinant tissue-type plasminogen activator (rt-PA, alteplase, or tPA) in patients receiving a diagnosis of ischemic stroke, proponents of this treatment may have heaved a sigh of relief. 

Nearly 2 decades after tPA received Food and Drug Administration (FDA) approval for this indication, the much-debated National Institute of Neurological Disorders and Stroke trials2 appeared vindicated, with these influential organizations elevating intravenous tPA treatment within 3 hours of symptom onset to a level A recommendation. The actual wording specifies that “IV tPA should be offered,” not that it must always be given, “to acute ischemic stroke patients who meet National Institute of Neurological Disorders and Stroke (NINDS) inclusion/exclusion criteria.” Thrombolysis proponents might infer that entrenched resistance, particularly among emergency physicians,3 is likely to dwindle. The only known acute treatment for stroke can reach more patients and benefit most of them. 

Not so fast, say some observers of the controversy. Many things about tPA are uncertain; its association with more intracranial hemorrhages is not one of them. Whether the clot-busting treatment correlates with improved outcomes clearly enough to outweigh that risk, particularly when the urgent time factor (only treatment within the 3-hour window receives the ACEP/AAN level A recommendation, whereas treatment within 4.5 hours gets a level B) adds pressure to the uncertainties inherent in a diagnosis of exclusion, is a settled question to some and an open question to others. At least 1 prominent skeptic toward tPA views the available evidence as not only inconclusive at best but also perhaps inconsistent with the proposed mechanism of action altogether. 

With widespread reluctance to use tPA acknowledged by both proponents and skeptics, and with shifting incentives affecting therapeutic policies, the new guidelines may foster as much confusion and polarization as they resolve. Experience with tPA can fit into either a narrative of progress and obstructionism or one of earnest (albeit profit-enhanced) wishful thinking. The physician seeking a definitive answer may be in the position of solitude and inescapable responsibility that Jean-Paul Sartre described in a 1946 lecture: “[I]f you seek counsel … at bottom you already knew, more or less, what [a given counselor] would advise. In other words, to choose an adviser is nevertheless to commit oneself by that choice.”4 

15. Capnography Useful in Identifying Patients with DKA  

In this study, end tidal CO2 values greater than 24.5 mm Hg excluded DKA in most hyperglycemic patients.  

Soleimanpour H et al. West J Emerg Med 2013 [Epub ahead of print] 

Introduction: Metabolic acidosis confirmed by arterial blood gas (ABG) analysis is one of the diagnostic criteria for diabetic ketoacidosis (DKA). Given the direct relationship between end-tidal carbon dioxide (ETco2), arterial carbon dioxide (PaCO2) and metabolic acidosis, measuring  ETco2 may serve as a surrogate for ABG in the assessment of possible DKA. The current study focuses on the predictive value of capnography in diagnosing DKA in patients referring to the emergency department (ED) with increased blood sugar levels and probable diagnosis of DKA. 

Methods: In a cross-sectional prospective descriptive-analytic study carried out in an ED, we studied 181 patients older than 18 years old with blood sugar levels of higher than 250 mg/dl and probable DKA. ABG and capnography were obtained from all patients. To determine predictive value, sensitivity, specificity and cut-off points, we developed receiver operating characteristic curves. 

Results: Sixty-two of 181 patients suffered from DKA. We observed significant differences between both groups (DKA and non-DKA) regarding age, pH, blood bicarbonate, PaCO2 and ETco2 values (P≤0.001). Finally, capnography values more than 24.5 mmHg could rule out the DKA diagnosis with a sensitivity and specificity of 0.90. 

Conclusion: Capnography values greater than 24.5 mmHg accurately allow the exclusion of DKA in ED patients suspected of that diagnosis. Capnography levels lower that 24.5 mmHg were unable to differentiate between DKA and other disease entities. 

16. Vaccines Not Linked to Guillain-Barré, Asserts 13-Year Trial 

Fran Lowry. Jun 26, 2013. Medscape News.  

In a retrospective study spanning 13 years and more than 30 million person-years, researchers found no evidence of an increased risk for Guillain-Barré Syndrome (GBS) after vaccinations of any type, including influenza vaccination. 

"If there is a risk of Guillain-Barré syndrome following any vaccine, including influenza vaccines, it is extremely low," lead author Roger Baxter, MD, codirector of the Kaiser Permanente Vaccine Study Center, Oakland, California, said in a Kaiser news release. 

"GBS is an acute inflammatory polyradiculoneuropathy affecting primarily motor neurons, which in severe cases can progress to complete paralysis and even death," write Dr. Baxter and colleagues in an article published online April 11 and in the July 15 issue of Clinical Infectious Diseases. 

"Estimates of GBS incidence are in the range of 1-2 cases per 100,000 person-years worldwide and increase with age," cite the authors. Causes of the syndrome are unknown, but are thought to involve an autoimmune process triggered by antigenic stimulation that results in demyelination and destruction of peripheral nerves, the authors explain. 

About two thirds of cases are preceded by a gastrointestinal or respiratory infection, with Campylobacter enteritis being the most common trigger. Also implicated are influenza, cytomegalovirus, Epstein-Barr virus, HIV, and Mycoplasma pneumonia. 

Case reports have linked a variety of vaccine types to GBS. The only clear association, however, has been with the 1976 A/New Jersey swine influenza vaccine, when a small but significant increase in the number of GBS cases was seen 6 weeks after vaccination. Since that time, investigations have shown either no risk or a very small attributable risk of GBS in roughly 1 case per million doses. More recently, studies assessing the risk of GBS after the 2009 H1N1 monovalent influenza vaccines in the United States found a slightly higher attributable risk ranging from 1 to 5 per million doses. 

The aim of the current study was to further evaluate the possible relationship between GBS and vaccinations, using retrospective data from the Kaiser Permanente of Northern California healthcare plan accumulated over many years. 

Dr. Baxter and colleagues identified 415 confirmed cases of GBS during the 13-year period from 1994 to 2006. Most cases were male (58.6%), and the mean age was 48.5 years (range, 5 - 87 years). 

The researchers also found that 277 patients (66.7%) had a respiratory and/or gastrointestinal illness in the 90 days preceding the onset of GBS. 

Incidence was significantly more likely to occur in the winter months (November - April), with a relative risk of 1.5, compared with in the nonwinter months (P = .003), peaking in March. 

Among the 415 patients with GBS, only 25 had received any vaccine in the 6 weeks before onset of the disease. The vaccines that were received included trivalent inactivated influenza vaccine (n = 18 patients), 23-valent polysaccharide pneumococcal vaccine (n = 2), tetanus-diphtheria combination vaccines (n = 3), hepatitis A (n = 2), and hepatitis B (n = 1). 

The other 390 patients with GBS received no vaccines in the 6 weeks before onset. 

The researchers also found no cases of GBS resulting from vaccines given mainly in childhood, despite the large number of doses given. These included the oral polio vaccine (1.2 million doses), measles-mumps-rubella (1.6 million), conjugated pneumococcal (1.3 million), live attenuated influenza (69,000), diphtheria-tetanus-acellular pertussis (1.9 million), varicella (764,000), Haemophilus-diphtheria-tetanus-pertussis (525,000), and Haemophilus B vaccines (1.2 million). 

"For rabies vaccine (13 000 doses), there was 1 case of GBS, 7.5 weeks after vaccination," the authors add. 

"Despite many years of review of a very large captured population, we are unable to exclude any [and all] possible association between vaccines and GBS," the researchers note. This is in part because of the low power of the study, given the infrequency with which GBS occurs. 

Highlighting another potential study limitation, the authors point out that their reviewer was able to see whether medical providers thought that GBS was caused by a vaccine, which "could have influenced the reviewer in some way." 

Nonetheless, "the low numbers of GBS cases that were temporally associated with vaccination, coupled with our results, provide reassurance that the risk of GBS following any vaccine, including influenza vaccines, is extremely low," conclude Dr. Baxter and colleagues. 

17. Quick Lit Reviews 

A. Is SQ Sumatriptan an Effective Treatment for Adults Presenting to the ED with Acute MHA? 

Jones S, et al. Ann Emerg Med. 2013;62:11-12.  

Take-Home Message: Subcutaneous sumatriptan provides effective treatment of migraine headaches, quickly eliminating pain and associated symptoms; however, it has yet to be proven as an optimal emergency department (ED) treatment modality because of inadequate evidence of effectiveness in this setting, increased self-limiting adverse events, and a high recurrence of pain within 24 hours. 

B. Do Fluids Facilitate Stone Passage in Acute Ureteral Colic? 

Kirschner J, et al. Ann Emerg Med. 2013;62:36-37.  

Take-Home Message: High-volume intravenous fluid therapy has not been shown to improve ureteral stone passage, pain control, or need for surgical stone removal. 

C. Do Vasopressors Improve Outcomes in Patients With Cardiac Arrest? 

Michiels EA, et al. Ann Emerg Med. 2013;62:57-58.  

Take-Home Message: Research evidence is currently inadequate to either support or reject the use of vasopressors in cardiac arrest. 

D. Are Benzodiazepines Effective for Alcohol Withdrawal? 

Schaefer TJ, et al. Ann Emerg Med. 2013;62:34-35.  

Take-Home Message: When compared with placebo, benzodiazepines offer significant benefit in preventing alcohol withdrawal seizures. 

E. Is coronary CTA useful in diagnosing ACS in the ED?  

Dipaola F, et al. Intern Emerg Med 2013;8:345–346. 

Clinical Bottom Line: The study showed that early CCTA-based evaluation strategy in a selected population without prior known coronary artery disease may improve the efficacy of ED triage for patients with suspected ACS by reducing length of hospital stay. However, this approach leads to increased diagnostic testing and higher radiation exposure and no overall reduction in the cost of care. The net benefit of this novel approach in the management of patients with suspected acute coronary syndrome in ED is yet to be clarified. 

18. EMCrit PodCast by Scot Weingart 

A.Is Lactate Clearance a Flawed Paradigm? (He says no)

B. Podcast 98 – Cyclic (Tricyclic) Antidepressant Overdose

C. The Vortex Approach to AW Management

19. Metoclopramide plus Diphenhydramine Superior to Ketorolac for Nonmigraine Headaches 

A randomized trial found better pain relief with the antiemetic combination than with the NSAID.  

Medications recommended for headache treatment include nonsteroidal anti-inflammatory drugs (NSAIDs), prochlorperazine, metoclopramide, and caffeine. These authors compared two regimens in adult patients with recurrent headaches that did not meet definitions for migraine or cluster headache. In a randomized, double-blind study, 120 patients who presented to an academic emergency department received either intravenous metoclopramide (20 mg) plus diphenhydramine (25 mg), or intravenous ketorolac (30 mg). 

After 1 hour, pain improvement was greater with the combination regimen (median improvement on an 11-point scale, 5 vs. 3 points). The combination regimen was also superior in sustained relief, requirement for rescue medications, and patient desire to receive the same treatment again. 

Comment: This study joins a long list of prior studies that suggest that metoclopramide and prochlorperazine are excellent agents for headache treatment. But it would be unfortunate if we concluded from this study that there is any reason to treat benign headaches with intravenous medications. There is also no reason to use only one of these regimens. Common sense suggests that we simply treat these benign conditions with oral ibuprofen, oral prochlorperazine or metoclopramide, and perhaps also oral caffeine. Opioids and barbiturate/analgesic combinations (e.g., Fiorinal) should not be used. 

— Daniel J. Pallin, MD, MPH. Published in Journal Watch Emergency Medicine June 21, 2013.
Citation: Friedman BW et al. Ann Emerg Med 2013 Apr 8 [e-pub ahead of print].  

20. Aspirin-clopidogrel combo may lower stroke recurrence risk 

Combining clopidogrel and aspirin can lower the risk of a second stroke by almost one-third compared with aspirin alone, according to a study in the New England Journal of Medicine. Researchers tracked more than 5,000 patients who survived a stroke or mini-stroke and found that 11.7% of those who took aspirin alone suffered another stroke compared with 8.2% of those who received the clopidogrel-aspirin combination. "Giving two drugs that block platelets works a lot better than aspirin alone in people who have had a minor stroke or TIA," a researcher said. An expert not involved in the study said providers have been moving away from the combination due to risk of serious bleeding. 

21. ACEP Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients in the ED with Asymptomatic Elevated BP 

Wolf SJ, et al. Ann Emerg Med. 2013;62:59-68.  

This clinical policy from the American College of Emergency Physicians is the revision of a 2006 policy on the evaluation and management of adult patients with asymptomatic elevated blood pressure in the emergency department.1 A writing subcommittee reviewed the literature to derive evidence-based recommendations to help clinicians answer the following critical questions: (1) In emergency department patients with asymptomatic elevated blood pressure, does screening for target organ injury reduce rates of adverse outcomes? (2) In patients with asymptomatic markedly elevated blood pressure, does emergency department medical intervention reduce rates of adverse outcomes? A literature search was performed, the evidence was graded, and recommendations were given based on the strength of the available data in the medical literature. 

22. An Absurdly Random, and Completely Blind, Review and Prospective Validation of Mathematical Truisms in EM and Critical Care 

Goodman T, et al. Ann Emerg Med. 2013;62:95.  

Study Objective: We thought that in the darkest part of night shifts, when the diurnal variation of our internal clocks is defunct and all organized neuronal electrical activity in the cerebrum has ceased, that mathematical truisms might be a valid tool in the assessment and treatment of the acutely ill, injured, or merely crazy patients in the emergency department (ED). Therefore, in support of evidence-based medicine, we sought to define and subsequently validate any mathematical information that may be clinically useful at 3 am. 

Methods: The initial phase of this megatrial was a retrospective review by multiple EMS personnel, nurses, and emergency physicians over a period of 10 years in Hawaii and Arizona. Data collection occurred in fire stations, EDs, bars, boats, and on surf breaks. The second phase of the trial was a prospective validation series of the mathematical information by this same author over the subsequent 20 years of working in an ED. Interrater reliability was irrelevant. 


1. Pulse ox less than age=get an ETT or a DNR order fast 

2. For adults: Pulse greater than systolic BP=get the paddles 

3. WBC greater than Hct=culture every orifice and call infectious disease 

4. Pulse less than Hct=don't know what it means, but it's a bad thing 

5. For Peds: If the number of problems on their chart is greater than age, then it's far too complicated to get involved; call Peds, but if chart weight is greater than patient's weight=means it's a genetic defect kid, so get a dictionary … then call Peds! 

6. Bands greater than Segs=bad, see 3 

7. The Tooth to Tattoo ratio … . If number of teeth still present less than tattoos=pt has guaranteed immortality, don't sweat the resuscitation 

8. Any stab wound through a tattoo is guaranteed to be lethal, so start sweating now.

9. BUN greater than Sodium=kidneys gone, call nephrology 

10. Age greater than Systolic BP=not a good sight on a triage note, immediately go to dinner and let your partner get that chart 

11. Allergies greater than 4=drug seeker or psychosomatic … stay at dinner longer. 

12. On an ABG, if pO2 less than pCO2=the patient is either an anaerobe or needs a great white snorkel in the lungs 

13.100–Age=Percent chance of going home from ED on any given visit 

14. Respiratory rate exceeds pulse=patient is either hyperventilating, on β-blockers, about to be arrested, or needs the great white snorkel (ETT) 

15. SED rate is greater than HcT … . Hhhmmm????? Haven't a clue, but it will make some internist happy for years figuring it out 

16. Meds×10 exceeds age, or Number of Problems on problem list+meds exceeds age=automatic admit 

Conclusion: Mathematical truism can be a helpful tool in our fight for sanity and sensible decisions in the ED at all hours of the day and night. However, future studies at posh hotels in exotic locations, and sponsored by hospitals or drug companies, are definitely required. 

23. Animal Behavior Books Altogether Unrelated to EM 

These were both good reads: engaging, informative, well-written, and easy to follow. You science-minded animal lovers will find these enjoyable. 

A. Virginia Morell, Animalwise: The Thoughts and Emotions of our Fellow Creatures (New York: Crown, 2013). http://www.amazon.com/dp/0307461440/  

B. Frans de Waal, The Bonobo and the Atheist: In Search of Humanism Among the Primates (New York: Norton, 2013). http://www.amazon.com/dp/0393073777/  

24. Very Many Tib Bits 

A. A specific antidote for reversal of anticoagulation by direct and indirect inhibitors of coagulation factor Xa. 

Lu G, et al. Nat Med. 2013 Apr;19(4):446-51. 

B. Exercise has positive effects on body fat, study finds 

Exercising regularly can cause the body to convert white fat into brown fat, which burns calories and could help prevent weight gain, according to a study presented at the American Diabetes Association's annual meeting. "Our results showed that exercise doesn't just have beneficial effects on muscle, it also affects fat," said researcher Kristin Stanford. 

C. Extended hours for PCPs may lead to fewer child ED visits 

Children's visits to emergency departments were reduced by 50% if their primary care doctors had evening office hours five or more days per week, according to a study in the Journal of Pediatrics. Strategies such as 24-hour phone service, e-mail or patient portal communication, and same-day sick visits did not result in reduced ED visits, researchers said. 

D. Silent MI Predictors 

Silent myocardial infarctions are more common than previously thought. In this study, 1 of 4 patients with suspected coronary artery disease had experienced a silent myocardial infarction; the extent on average is 10% of the left ventricle, and it is more common in diabetics. 

E. 20% of youths suffer from head trauma in their lifetime 

Canadian researchers surveyed 8,900 11- to 20-year-olds from Ontario and found that about 20% had a serious head trauma at some point in their lives. Sports injuries accounted for 56% of head trauma cases that happened in the last 12 months. Poor academic performance and frequent alcohol and cannabis use were linked to increased traumatic brain injury risk, according to the study in the Journal of the American Medical Association. 

F. IOM Report: Evidence Fails to Support Guidelines for Dietary Salt Reduction 

A report from the Institute of Medicine (IOM) finds no evidence that drastically reducing salt, and the sodium it contains, in individuals' diets reduces the risk of myocardial infarction, stroke, or death. The US Centers for Disease Control and Prevention (CDC) and the American Heart Association (AHA) beg to differ. 

G. Ciguatera Fish Poisoning 

H. More pedestrians land in EDs for using cellphones while walking 

The number of pedestrians who were taken to the emergency department for injuries related to cellphone use increased from 1,055 in 2008 to 1,506 in 2010, according to a study in the journal Accident Analysis and Prevention. Researchers looked at a federal database of ED visits between 2004 and 2010 and found that young adults sustained the most number of pedestrian injuries caused by the use of cellphones while walking. 

I. Why Do I Think Better after I Exercise? 

—Emily Lenneville, Baltimore. Scientific American, June 23, 2013.  

Justin Rhodes, an associate professor of psychology at the University of Illinois at Urbana-Champaign, responds: 

After being cooped up inside all day, your afternoon stroll may leave you feeling clearheaded. This sensation is not just in your mind. A growing body of evidence suggests we think and learn better when we walk or do another form of exercise. The reason for this phenomenon, however, is not completely understood. 

Part of the reason exercise enhances cognition has to do with blood flow. Research shows that when we exercise, blood pressure and blood flow increase everywhere in the body, including the brain. More blood means more energy and oxygen, which makes our brain perform better. 

Another explanation for why working up a sweat enhances our mental capacity is that the hippocampus, a part of the brain critical for learning and memory, is highly active during exercise. When the neurons in this structure rev up, research shows that our cognitive function improves. For instance, studies in mice have revealed that running enhances spatial learning. Other recent work indicates that aerobic exercise can actually reverse hippocampal shrinkage, which occurs naturally with age, and consequently boost memory in older adults. Yet another study found that students who exercise perform better on tests than their less athletic peers. 

The big question of why we evolved to get a mental boost from a trip to the gym, however, remains unanswered. When our ancestors worked up a sweat, they were probably fleeing a predator or chasing their next meal. During such emergencies, extra blood flow to the brain could have helped them react quickly and cleverly to an impending threat or kill prey that was critical to their survival. 

So if you are having a mental block, go for a jog or hike. The exercise might help pull you out of your funk. 

J. Patients’ attitudes about the use of placebo treatments: telephone survey 

Hull SC, et al. BMJ 2013;347:f3757  

Objective To examine the attitudes of US patients about the use of placebo treatments in medical care. 

Design One time telephone surveys. 

Setting Northern California. 

Participants 853 members of Kaiser Permanente Northern California, aged 18-75, who had been seen by a primary care provider for a chronic health problem at least once in the prior six months.  

Results The response rate was 53.4% (853/1598) of all members who were eligible to participate, and 73.2% (853/1165) of all who could be reached by telephone. Most respondents (50-84%) judged it acceptable for doctors to recommend placebo treatments under conditions that varied according to doctors’ level of certainty about the benefits and safety of the treatment, the purpose of the treatment, and the transparency with which the treatment was described to patients. Only 21.9% of respondents judged that it was never acceptable for doctors to recommend placebo treatments. Respondents valued honesty by physicians regarding the use of placebos and believed that non-transparent use could undermine the relationship between patients and physicians.  

Conclusions Most patients in this survey seemed favorable to the idea of placebo treatments and valued honesty and transparency in this context, suggesting that physicians should consider engaging with patients to discuss their values and attitudes about the appropriateness of using treatments aimed at promoting placebo responses in the context of clinical decision making. 

K. National Athletic Trainers’ Association, Inc releases new evidence-based guidelines on management of ankle sprains 

Kaminski TW, et al. Journal of Athletic Training 2013;48(4):528–545 

L. Science or Science Fiction? 12 Cutting-Edge Medical Advances 

M. 'I Can't Give You That Test': How to Tell Patients 

Shelly Reese. Medscape Business of Medicine. Jun 26, 2013 

Full-text (free after one-time registration): http://www.medscape.com/viewarticle/806628