Oral Zinc for the Common Cold

128 mL/min to maintain Sn 0.80 and NPV 0.90. Therefore, the authors conclude that the value of D-dimer required to rule out PE increased substantially with decreasing GFR. As such, the specificity of D-dimer for PE decreased substantially with declining eGFR. In fact, only 12% of patients with eGFR 30–60 mL/min and no patients with eGFR < 30 mL/min had a D-dimer value < 500 mg/L. Authors urge that larger studies are needed to determine renal function-adjusted D-dimer cutoffs before D-dimer can be safely applied to patients with renal insufficiency. [Brian Jekich, MD Denver Health Medical Center, Denver, CO] Comment: Patients with renal insufficiency in whom the diagnosis of PE is being considered present a diagnostic challenge. This article demonstrates that patients with renal insufficiency have elevated D-dimer levels and thus, may be poor candidates for applying the accepted value of < 500 mg/L for ruling out the diagnosis of PE. However, given that the Sn of D-dimer was 100% when the D-dimer was < 500 mg/L, it may be worth considering this test prior to obtaining CTA. Alternatively, if the patient is felt to be very low risk by clinical decision rules, D-dimer should not be obtained, as patients with renal insufficiency are likely to have elevated D-dimer in the absence of a thromboembolic event. , THE EFFECT OF NEW DUTY HOURS ON RESIDENT ACADEMIC PERFORMANCE AND ADULT RESUSCITATION OUTCOMES. Pepper DJ, Schweinfurth S, Herrin VE. Am J Med 2014;127:337–42. The implementation of changes in resident duty hours by the Accreditation Council for Graduate Medical Education (ACGME) on July 1, 2011 necessitated changes in resident work schedules. The revision in duty-hours standards by the ACGME intends to promote patient safety while also improving resident wellness and reducing fatigue. In this retrospective cohort study conducted at a single academic hospital, authors compared outcomes for emergency resuscitations that occurred on the inpatient medical floors for the periods of July 2010 to June 2011 and July 2011 to June 2012. Emergency resuscitations were led by postgraduate year 2 or 3 internal medicine (IM) residents and included the spectrum of cardiac and respiratory arrest, as well as ‘‘code blues,’’ which required an escalating level of care for an unstable patient. Prior to July 2011, this academic institution utilized an on-call resident for a 30-h shift to respond to emergency resuscitations and code blues. After July 2011, this institution implemented a night float system, whereby the on-call team worked no more than 16 consecutive daytime hours, and a night team relieved the on-call team for overnight shifts. Authors found that there were a similar proportion of deaths, transfers to the intensive care unit, and stabilization of patients on the floor prior to and after implementation of new duty-hours rules. Using multivariate regression analysis, authors found a reduction in the number of patients requiring transfer to the intensive care unit after code blues after implementation of new duty-hours rules (adjusted odds ratio 0.59;

Abstracts 95% confidence interval 0.37–0.92). Additionally, authors compared resident annual in-service training examination scores between 2009 and 2012, hypothesizing that changes in duty hours would provide residents increased opportunities for rest and education. Conversely, authors saw a small but significant decrease in the median delta percentage scores for inservice examinations for the period from 2009 to 2010 when compared to 2011 to 2012 (p = 0.02). Based on these results, the authors conclude that a night float system, adopted after implementation of the new duty-hours rules, may allow greater overnight continuity of patient care and decrease resident fatigue when making decisions about unstable patients. They point out that there was no increase in mortality or adverse events after July 2011, which may suggest that a reduction in resident duty hours does not necessarily adversely affect patients, as has been previously suggested. [Brian Jekich, MD Denver Health Medical Center, Denver, CO] Comment: The generalizability of these data to emergency medicine (EM) residency programs is limited, as IM residents work schedules that do not accurately reflect that of the emergency department. Additionally, IM and EM residents possess different skill sets with regard to emergency resuscitation. The decline in in-service examination scores seen in this study needs to be followed with larger multicenter studies to determine if these results are consistent across other populations of residents and specialties. , ORAL ZINC FOR THE COMMON COLD. Das RR, Singh M. JAMA 2014;311:1440–1. Oral zinc is a commonly used supplement thought to decrease the incidence, duration, and severity of symptoms from the common cold by blocking the attachment of human rhinoviruses to nasal epithelial cells via the intracellular adhesion molecule 1. This JAMA clinical evidence synopsis summarizes a Cochrane review of 14 therapeutic trials of zinc supplementation and two trials of prophylactic use, altogether analyzing 1781 patients across five countries. The authors found that zinc decreased the mean duration of symptoms when administered within 24 h of symptom onset in both a lozenge and syrup form, from 7.5 days to 6.75 days and from 5.9 days to 5.1 days, respectively. The effect was dose dependent, with the mean duration of the common cold being 4.47 days in high-dose users and 8.68 days in low-dose users. Symptom severity score was unchanged between the two groups. However, zinc lozenges were associated with a higher incidence of adverse effects compared with placebo, the most common adverse effects being bad taste and nausea. When examined for its prophylactic use, the Cochrane review examined two trials with 761 pediatric patients. Zinc was found to decrease the incidence of the common cold in children from 61.8% to 38.2%. Since publication of the review, a randomized controlled trial evaluated the efficacy of zinc bisglycinate tablets taken over 3 months in preventing cold symptoms. The results showed reduction in colds with two symptoms (38% on zinc vs. 54% on placebo) and three symptoms (12% for zinc and 26% for

The Journal of Emergency Medicine placebo). The authors pointed out that the bad taste of zinc tablets could have affected blinding in their study, and that the dose of ionic zinc was highly variable across trials included in their analysis. Additionally, there is a high risk for publication bias. [Benjamin Murphy, MD Denver Health Medical Center, Denver, CO] Comments: This summary of a Cochrane review provides strong evidence for the efficacy of zinc in shortening the duration of cold symptoms and in preventing the common cold in children. It is important to note that the study did not include high-risk populations such as asthmatics or the immunocompromised, so the results may not be applicable to those individuals. Additionally, future prophylactic studies should be extended to the adult population. , NEW ELECTROCARDIOGRAPHIC CRITERIA TO DIFFERENTIATE ACUTE PERICARDITIS AND MYOCARDIAL INFARCTION. Rossello X, Wiegerinck RF, Alguiersuari J, et al. Am J Med 2014;127:233–9. Accurately diagnosing ST-segment elevation myocardial infarctions (STEMIs) in the emergency department can prove to be a challenging task, and misdiagnosis can lead to unnecessary coronary angiography. This article from four tertiary hospitals in Spain sought to improve the distinction between pericarditis and STEMI by examining the duration of the QRS complex and QT interval. The authors hypothesized that the QRS interval would be prolonged in acute MI due to slowed propagation of the local activation front by transmural ischemia; the QT interval was expected to be shortened in the acute period. They performed a multi-centric case-control study examining 150 patients with acute chest pain associated with ST elevation: 71 who presented with STEMIs and 79 who had acute pericarditis. Admission electrocardiograms (ECGs) were manually analyzed for deviation of the PR segment from baseline, ST-segment deviation from the J-point, QRS duration, and QT interval. Each ECG was analyzed using one of three models: Model A included the duration of the QRS complex and QT interval; Model B utilized the classic ECG criteria of PR deviation and J-point level in aVR, as well as the number of leads with ST-segment elevation, ST-segment depression, and PR depression; and Model C tested all of the above variables. Receiver operating characteristic curves (ROCs) were constructed for each model, and the ROCs were compared using the DeLong method. Overall, patients with acute pericarditis were younger with fewer cardiac risk factors. Additionally, these patients showed greater upright PR deviation and deeper J-point in aVR, as well as a higher number of ECG leads with ST elevation and PR depression and a lower number of leads with reciprocal ST depression compared to STEMI ECGs. In patients with pericarditis, the QRS and QT intervals were the same in leads with and without ST elevation, whereas patients diagnosed with STEMIs showed a longer duration of the QRS complex and shorter QT interval length in leads with ST elevation compared to isoelectric leads. Comparison of the aforementioned models showed improvement in the ROC when QRS and QT interval duration were included in the anal-

129 ysis, with the ROC for model A being 0.807, model B 0.863, and model C 0.914. This study demonstrates that factoring the QRS duration and QT interval in your analysis of an ECG can help the clinician identify pericarditis and acute STEMI. The authors note that the study was limited by a lack of randomization, and that the ECG findings significantly influenced the ultimate diagnosis for patients at discharge. [Benjamin Murphy, MD Denver Health Medical Center, Denver, CO] Comments: This study provides evidence for additional ECG findings that can help the clinician distinguish between pericarditis and acute STEMI. The small and nonrandomized nature of the study necessitates the need for a large randomized control trial to provide validation of their diagnostic algorithm. Additionally, the authors compare the QRS duration and QT interval in leads with and without ST elevation, but one of the common features of pericarditis is diffuse ST elevation, often throughout all leads. Diffuse ST elevation could make such a comparison difficult to apply clinically and to accurately interpret in the context of this study. Additionally, future studies should use a separate gold standard for diagnosis of pericarditis that doesn’t include ECG interpretation. , ULTRASONOGRAPHY/MRI VERSUS CT FOR DIAGNOSING APPENDICITIS. Aspelund G, Fingeret A, Gross E, et al. Pediatrics 2014;133:586–93. This study sought to compare computed tomography (CT) scan to a radiation-free imaging strategy using ultrasound followed by magnetic resonance imaging (MRI) as needed to diagnose appendicitis in children. A cohort of 662 children from 2008–2012 was divided into 265 children presenting from 2008–2010 who received CT imaging, and 397 children from 2010–2012 who received ultrasound followed by MRI for equivocal findings of suspected appendicitis. In the CT group, 55% were positive for appendicitis when CT was used and the negative appendectomy rate was 2.5%. In the ultrasound/MRI group, 365 (91.9%) had ultrasound initially. Of those, 206 were read as equivocal (72 positive and 87 negative) and 142 of those children then had MRI. In the MRI group, 80 were negative and 62 were positive. The overall rate of appendicitis in the ultrasound/MRI group was 41% and the negative appendectomy rate was 1.4%. The time to antibiotics and operation from triage, as well as the perforation rates, was the same in both groups. The study concludes that a radiation-free strategy of ultrasound selectively followed by MRI is feasible and comparable to CT in diagnosing appendicitis in children. [Justin S. McLean, MD Denver Health Medical Center Denver, CO] Comment: Overall, this is an important study as we continue to move away from CT scans in children to diagnose appendicitis because the findings show no difference in clinical endpoints between the two strategies. One area of issue in this study is that the ultrasound/MRI group did include 54 (13.6%) CT scans in its cohort. It is unclear how this may skew the results. Finally, the article does not address the cost difference