Early Head to Pelvis Computed Tomography in Out‐of‐Hospital Circulatory Arrest Without Obvious Etiology

OBJECTIVES Patients resuscitated from an out-of-hospital circulatory arrest (OHCA) commonly present without an obvious etiology. We assessed the diagnostic capability and safety of early head-to-pelvis computed tomography (CT) imaging in such patients. METHODS From 11/2015 to 2/2018, we enrolled 104 patients resuscitated from OHCA without obvious cause (idiopathic OHCA) to an early sudden death CT (SDCT) scan protocol within 6 hours of hospital arrival. The SDCT protocol included a non-contrast CT head, an electrocardiogram-gated cardiac and thoracic CT angiogram, and a non-gated venous phase abdominopelvic CT angiogram. Patients needing urgent cardiac catheterization or hemodynamically unable to tolerate SDCT were excluded. Cardiac CT analyses were blinded, but other SDCT findings were clinically available. Primary endpoints were the number of OHCA causes identified by SDCT compared to the adjudicated cause, and critical diagnoses identified by SDCT, including resuscitation complications. Safety endpoints were acute kidney injury and inappropriate treatments based on SDCT findings. Acute coronary syndrome was the presumed etiology if any major coronary artery had a >50% stenosis without another OHCA cause. RESULTS SDCT scans occurred within 1.9±1.0 h of hospital arrival and identified 39% (41/104) of all OHCA causes and 95% (39/41) of causes potentially identifiable by SDCT. Critical findings were identified by SDCT in 98% (43/44) of patients that included potentially life-threatening resuscitation complications of liver or spleen laceration (n=6), pneumothorax or thoracic organ laceration (n=8), and mediastinal, pericardial, or vascular hemorrhage (n=3). SDCT exclusively identified 13 (13%) OHCA causes that would otherwise not be identified without SDCT imaging. No inappropriate treatments resulted from SDCT findings. Acute kidney injury was common (28%) but only 1 (1%) patient required new dialysis. CONCLUSIONS This observational cohort study suggests that early SDCT scanning is safe, can expedite the diagnosis of potential causes, and can meaningfully change clinical management after idiopathic OHCA.