195 Screening Electrocardiograms in Cocaine-Positive Chest-Pain-Free Psychiatric Patients Requiring Medical Clearance

Abstract

Current practice at our large, public, urban academic emergency department (ED) is to obtain a screening electrocardiogram (ECG) as part of the medical clearance process on all patients who require transfer to an inpatient psychiatric facility and test positive for cocaine on a urine toxicology screen regardless of the presence or absence of chest pain. The purpose of this retrospective quality improvement study is to examine the utility and impact of a screening ECG for patients with urine toxicology screening positive for cocaine who are chest-pain-free and require medical clearance prior to transfer to an inpatient psychiatric facility. An institutional review board-approved, retrospective chart review between January 2014 - December 2015 was performed of all ED patients (1) over 18 years of age, (2) without chest pain documented in the medical record, (3) who required medical clearance in the ED prior to transfer to an inpatient psychiatric facility, (4) who tested positive for cocaine on a screening urine toxicology test, and (5) for whom a screening ECG was obtained. All ECGs were interpreted by an attending physician. Abnormal ECGs were defined as: nonspecific ST changes, T wave inversions, sinus tachycardia, ST elevation, or ST depression. All abnormal ECGs were compared to prior ECGs if available, and if no change noted then these were categorized as normal. Primary outcome was disposition of the patient to an inpatient psychiatric facility versus inpatient medical admission. Secondary outcomes were rates of a subsequent cardiac workup, including inpatient medical admission, cardiac enzymes, stress testing, cardiology consultation, and cardiac catheterization. During the study period, 1968 ED patients tested positive for cocaine on a urine toxicology screen and 853 met inclusion criteria. ECGs were normal in 809 (95%, 95% CI [93%, 96%]) patients, and abnormal in 44 (5%, 95% CI [4%, 7%]) patients. Of the 44 patients with abnormal ECGs, 4 were admitted for a cardiac workup. Two patients had positive troponins in the ED. Two patients had cardiology consultations and 3 had further cardiac stress testing performed, all of which were negative or non-diagnostic. No cardiac catheterizations were performed on any patients. Based on the results of our study, the majority of ED patients with recent cocaine use but without chest pain have a normal ECG. Of the minority of patients with an abnormal ECG, there were no cases of acute myocardial ischemia or infarction identified in the absence of chest pain. Therefore, a screening ECG in patients without chest pain simply because of a cocaine-positive urine toxicology test does not appear to identify any cases of myocardial ischemia or infarction and may, in fact, lead to over-testing, increased admission, misuse of resources, and increased cost. Limitations of this study include its retrospective, chart review design. Additionally, there is the possibility of a patient not being forthcoming regarding the presence or absence of chest pain and being categorized incorrectly.