Letter to the Editor
Many emergency physicians were surprised and even concerned by the high prevalence of pulmonary embolism in patients hospitalized for a first episode of syncope in the PESIT study (97/560=17.3%), discussed in Dr. Rory Speigel's article. (“Statistical Hoodwinkery and Bad Medicine: All Syncope Patients Don't Need a PE Workup,” EMN 2017;39:31; http://bit.ly/2j4wlI0.) This was not a study of emergency department patients, nor did the authors present it as such. If one uses the number of patients who presented to the emergency department with syncope as the denominator, the prevalence was 97/2584=3.8 percent.
Patients in one study whose pulmonary embolism was hemodynamically significant enough to cause syncope usually had hypotension on arrival in the emergency department and always had room air hypoxia. (JAMA 1977;238:2509.) PIOPED II found that dyspnea or tachypnea occurred in 92 percent of patients with pulmonary embolism in main or lobar pulmonary arteries. (Am J Med 2007;120:871.) This study is a useful reminder that pulmonary embolism is an important potential cause of syncope, but a workup for pulmonary embolism is not indicated if an emergency department patient who was brought in for syncope is now breathing comfortably and has normal blood pressures and oximetry.
Michael A. Kohn, MD, MPP