Faculty Bibliography

BACKGROUND:Accurate electrocardiographic (ECG) differentiation of ventricular tachycardia (VT) from supraventricular tachycardia with aberrancy (SVT-A) on ECG is key to therapeutic decision-making in the emergency department (ED) setting. OBJECTIVE:The goal of this study was to test the accuracy and agreement of emergency medicine residents to differentiate VT from SVT-A using the Vereckei criteria. METHODS:Six emergency medicine residents volunteered to participate in the review of 114 ECGs from 86 patients with a diagnosis of either VT or SVT-A based on an electrophysiology study. The resident reviewers initially read 12-lead ECGs blinded to clinical information, and then one week later reviewed a subset of the same 12-lead ECGs unblinded to clinical information. RESULTS:One reviewer was excluded for failing to follow study protocol and one reviewer was excluded for reviewing less than 50 blinded ECGs. The remaining four reviewers each read 114 common ECGs blinded to clinical data and their diagnostic accuracy for VT was 74% (sensitivity 70%, specificity 80%), 75% (sensitivity 76%, specificity 73%), 61% (sensitivity 81%, specificity 25%), and 68% (sensitivity 84%, specificity 40%). The intraclass correlation coefficient (ICC) was 0.31 (95% CI 0.22-0.42). Eliminating two of the four reviewers who left a disproportionately high number of ECGs unclassified resulted in an increase in overall mean diagnostic accuracy (70-74%) and agreement (0.31-0.50) in the two remaining reviewers. Three reviewers read 45 common ECGs unblinded to clinical information and had accuracies for VT 93%, 93% and 78%. CONCLUSION/CONCLUSIONS:The new single lead Vereckei criteria, when applied by emergency medicine residents achieved only fair-to-good individual accuracy and moderate agreement. The addition of clinical information resulted in substantial improvement in test characteristics. Further improvements (accuracy and simplification) of algorithms for differentiating VT from SVT-A would be helpful prior to clinical implementation.

OBJECTIVE:The National Council on Radiation Protection (NCRP) limits health care-associated occupational exposures to radiation to 5000 mrem/y. Previous studies suggested that emergency physicians were not exposed over this limit. Their relevance to contemporary practice is unknown. We hypothesized that emergency physicians are currently exposed to radiation levels above the NCRP limits. METHODS:This prospective cohort study was conducted at an urban, academic, level I trauma center emergency department (ED). Thermoluminescent dosimeter radiation badges were placed on the torso and ring finger of all physicians staffing the ED during May 2008. Thermoluminescent dosimeter badges were affixed to 8 portable phones that are carried by physicians in the ED 24 hours a day. At the end of the study period, exposure dose for each subject was estimated. RESULTS:Seventy-five physicians enrolled in the study; 41 residents worked a median of 94 hours and 34 attendings worked a median of 54 hours. Compliance for physician badge wearing was 99%, ring wearing was 98%, and phone wearing was 100%. Two subjects had detectable levels of radiation on their torso thermoluminescent dosimeters of 4 and 1 mrem, respectively. One phone badge had a detectable level of 1 mrem. The annual extrapolated exposure for the subject with the highest radiation level would have been 50 mrem, below the 5000 mrem exposure limit for health care workers. CONCLUSION/CONCLUSIONS:Emergency physicians working in an urban, academic, level I trauma center ED do not appear to be at risk of exceeding the NCRP dose limits for ionizing radiation exposure to their torso or extremities.