Abstract 251: Brain Computed Tomography After In-Hospital Cardiac Arrest

Background: Brain computed tomography (CT) is useful to identify early cerebral edema after cardiac arrest and neurological causes arrest. Most early CT data come from out-of-hospital cardiac arrest (OHCA). The prevalence of edema and neurological causes of arrest is unknown after in-hospital cardiac arrest (IHCA). Purpose: To compare the frequency of edema and neurologic causes of arrest after IHCA and OHCA. Methods: We identified patients treated at a single medical center between January 2010 and August 2020 who had a brain CT within 24 hours of arrest. We abstracted age, sex, initial cardiac rhythm, duration of arrest, and survival to hospital discharge in all patients, and cause of death in decedents. We measured grey to white matter ratio (GWR) at the level of the basal ganglia. We categorized GWR as normal (1.30), mild edema (>1.20 and <1.30), and severe (1.20). We compared age, duration of arrest, GWR and edema category by arrest location using Wilcoxon-Rank-Sum and Fisher’s Exact tests. Results: Of 2,413 subjects (464 (19%) IHCA and 1949 (81%) OHCA), 1,725 had a brain CT within 24 hours of collapse (IHCA n=157, 9%; OHCA n=1,568, 91%) and were included. Subjects who suffered IHCA were significantly older (median 64 [interquartile range (IQR) 54 - 74] years vs 59 [IQR 49-70] years), had shorter CPR durations (IHCA median 10 [IQR 5-18] vs OHCA median 21 [IQR 13 - 34], p <0.001) and higher GWR (IHCA median 1.33 [1.29 - 1.41], OHCA median 1.3 [1.20 - 1.36], p<0.001). Severe edema was less common in IHCA (n=8, 5%) than OHCA (n=270, 24%). Mild edema was common after IHCA (n=49, 32%). Few CT scans revealed a neurological etiology of arrest (IHCA n=3, 2%; OHCA n=63, 4%). In-hospital death increased with edema, (no edema, n=48, 50%; mild, n=36, 73%; severe, n=8, 100%). Among deaths, 50% were attributed to perceived poor neurological prognosis. Conclusions: While severe edema is not as common as after OHCA, mild edema is relatively common after IHCA. Preventing and treating cerebral edema is important for survivors of IHCA.