ORIGINAL CONTRIBUTION Bedside Echocardiography by Emergency Physicians From the Department of Emergency Diku P. Mandavia, MD, FRCPC Study objective: Timely diagnosis of a pericardial effusion is Medicine, Los Angeles County+ Richard J. Hoffner, MD often critical in the emergency medicine setting, and echocar- University of Southern California Kevin Mahaney, MD Medical Center, Keck School of diography provides the only reliable method of diagnosis at the Sean O. Henderson, MD Medicine at the University of bedside. We attempt to determine the accuracy of bedside Southern California, Los Angeles, CA. echocardiography as performed by emergency physicians to Author contributions are provided detect pericardial effusions in a variety of high-risk populations. at the end of this article. Received for publication Methods: Emergency patients presenting with high-risk crite- September 26, 2000. Revision ria for the diagnosis of pericardial effusion underwent emer- received March 29, 2001. Accepted gency bedside 2-dimensional echocardiography by emergency for publication June 27, 2001. physicians who were trained in ultrasonography. The presence Presented in part at the Society for Academic Emergency Medicine or absence of a pericardial effusion was determined, and all annual meeting, Chicago, IL, images were captured on video or as thermal images. All emer- May 1998; the California Chapter- gency echocardiograms were subsequently reviewed by the American College of Emergency Physicians Scientific Assembly, Department of Cardiology for the presence of a pericardial effu- Monterey, CA, June 1998; and the sion. Seventh International Conference on Emergency Medicine, Vancouver, Results: During the study period, a total of 515 patients at British Columbia, Canada, high risk were enrolled. Of these, 103 patients were ultimately March 1998. deemed to have a pericardial effusion according to the compar- Address for reprints: ative standard. Emergency physicians detected pericardial effu- Diku P. Mandavia, MD, FRCPC, Department of Emergency Medicine, sion with a sensitivity of 96% (95% confidence interval [CI] Cedars-Sinai Medical Center, Room 90.4% to 98.9%), specificity of 98% (95% CI 95.8% to 99.1%), 1110, 8700 Beverly Boulevard, Los and overall accuracy of 97.5% (95% CI 95.7% to 98.7%). Angeles, CA 90048; E-mail [email protected]. Conclusion: Echocardiography performed by emergency Copyright © 2001 by the American physicians is reliable in evaluating for pericardial effusions; this College of Emergency Physicians. bedside diagnostic tool may be used to examine specific patients 0196-0644/2001/$35.00 + 0 at high risk. Emergency departments incorporating bedside 47/1/118224 doi:10.1067/mem.2001.118224 ultrasonography should teach focused echocardiography to evaluate the pericardium. [Mandavia DP, Hoffner RJ, Mahaney K, Henderson SO. Bedside echocardiography by emergency physicians. Ann Emerg Med. October 2001;38:377-382.] OCTOBER 2001 38:4 ANNALS OF EMERGENCY MEDICINE 377 BEDSIDE ECHOCARDIOGRAPHY BY EMERGENCY PHYSICIANS Mandavia et al INTRODUCTION approximately 3,600 to 4,000 are for major trauma patients. Few applications of emergency bedside ultrasonography The study was conducted prospectively from July 1997 are more time critical and potentially life-saving as 2- to December 1999. Consecutive emergency patients who dimensional echocardiography.1 It is well documented were at high risk for pericardial effusion according to both that ultrasonography can be learned by emergency physi- criteria and physician judgement underwent 2-dimensional cians2,3 and that this bedside tool is extremely valuable as echocardiography performed by the treating emergency part of the focused examination for trauma.4 The ability physician after informed consent. Three departmental to rapidly and accurately diagnose pericardial effusions in ultrasonography machines (Aloka models 1400 and the emergency department facilitates a wide variety of 1700, Aloka Company, Wallingford, CT; ATL 4, ATL, traumatic and nontraumatic symptoms; echocardiography Bothell, WA) with 2.5- to 3.0-MHz microconvex probes is the undisputed test of choice for the detection of peri- were used by emergency physicians during the study cardial effusion.5 Few data exist in this focused area of period. No clinical interventions were performed on the emergency ultrasonography, especially in a general emer- basis of the emergency physician echocardiographic gency population. This study prospectively examined the examination. If the patient was deemed to need a formal accuracy of echocardiography performed by emergency echocardiographic examination on an emergency basis, physicians in the detection of pericardial effusion. the Department of Cardiology performed the study. All participating physicians had previously taken a METHODS standardized 16-hour course on emergency ultrasonog- raphy that included 1 hour of instruction and 4 hours of This study was designed to assess the accuracy of echo- practical training dedicated to echocardiography.2 Echo- cardiography performed by emergency physicians to de- cardiography was taught in a focused manner, with the tect pericardial effusions. Emergency patients at high risk primary goal being the detection of a pericardial effusion. were defined before the study and are outlined in Figure All physicians were taught the following conventional 1. We prospectively identified cases, and 2-dimensional cardiac views: parasternal view, apical view, and subcostal echocardiography was performed on these selected view.6 A combination of these views using the long axis, patients. The captured studies were subsequently reviewed short axis, or 4-chamber plane was used by the emergency by a single echocardiographer from the Department of physician for the echocardiographic examination. Cardiology to determine the presence or absence of an All studies were recorded on videotape or thermal effusion; this overread was used as the comparative stan- paper, and special data collection forms were completed. dard. This study was approved by the local institutional The indication and presence or absence of a pericardial review board. effusion were noted. Echocardiograms were subse- Los Angeles County+University of Southern California quently reviewed by a single echocardiographer from the Medical Center hosts a large training program in emer- Department of Cardiology in a blinded fashion. gency medicine, is a Level I trauma center, and has an ED Sensitivity, specificity, positive and negative predictive that serves a local population of between 1.5 and 2 mil- values, overall accuracy, and 95% confidence intervals lion local inhabitants. Of the 155,000 annual ED visits, (CIs) were calculated using the F-distribution. SAS ver- sion 6.12 (SAS, Cary, NC) software was used for statistical analysis. Technically inadequate examinations were Figure 1. defined as images with poor image quality such that the High-risk populations for pericardial effusions. presence or absence of a pericardial effusion could not be discerned; these studies were excluded from analysis. 1. Unexplained hypotension or dyspnea 2. Cancer with chest pain or dyspnea RESULTS 3. Congestive heart failure/enlarged cardiac silhouette 4. Blunt chest injury A total of 515 echocardiographic examinations were com- 5. Penetrating chest injury 6. Uremia with chest pain or dyspnea pleted; of these, 478 (93%) examinations were considered 7. Pericarditis technically adequate. Breakdown by clinical indication 8. Systemic lupus erythematosis with chest pain or dyspnea and final result is shown in Table 1. The majority of exami- nations were performed for congestive heart failure, fol- 378 ANNALS OF EMERGENCY MEDICINE 38:4 OCTOBER 2001 BEDSIDE ECHOCARDIOGRAPHY BY EMERGENCY PHYSICIANS Mandavia et al lowed by blunt chest injury and patients with suspected strated its use in the noninvasive evaluation of cardiac pericarditis. A total of 103 pericardial effusions were trauma compared with subxiphoid pericardiotomy or detected. The overall sensitivity was 96% (95% CI 90.4% thoracotomy. Unfortunately, although echocardiography to 98.9%), and specificity was 98% (95% CI 95.8% to is being performed by surgeons with increasing frequency 99.1%). Positive predictive value was 92.5% (95% CI at many trauma centers, many of these studies only include 85.8% to 96.7%), and negative predictive value was 98.9% echocardiographic studies performed by echocardiogra- (95% CI 97.3% to 99.7%). Overall accuracy was excellent phers or cardiologists.4,12,13,15,17 at 97.5% (95% CI 95.7% to 98.7%) (Table 2). Table 3 Although many studies address ultrasonography per- details the study results according to individual indication. formed by emergency physicians, few studies have focused on echocardiography for the evaluation of pericardial effu- 18 DISCUSSION sions. In 1989, Mayron et al evaluated bedside echocar- diography in 156 patients, including those with nonper- Bedside echocardiography allows rapid, noninvasive fusing cardiac rhythms, hypotension, and chest trauma. In diagnosis of pericardial effusions and acute pericardial this study, emergency physicians were trained during a 4- tamponade.7 Physical examination findings such as Beck’s hour ultrasonography course. They detected 7 acute peri- triad, although commonly emphasized, are notoriously cardial effusions and felt that patient care had been unreliable and do not have a definitive role in modern enhanced in these cases. In 1995, Ma et al19 reported 245 medicine.8,9 Bedside 2-dimensional echocardiography