Abstract 319: Return of Spontaneous Circulation is Not Affected by Gastric Distension

Abstract

Introduction: Gastric distension is a common complication after CPR and is caused by excess gastric inflation. Consequently, regurgitation of gastric contents and diaphragmatic eventration with increased intrathoracic pressure can occur, which may lead to anoxia and ventricular diastolic dysfunction. We measured gastric volume of out-of-hospital cardiac arrest (OHCA) patients using computed tomography (CT) scan images, and examined the effect of gastric distension on the return of spontaneous circulation (ROSC). Hypothesis: Gastric distension from over-inflation is associated with decreased incidence of ROSC. Methods: We conducted a retrospective observational study with OHCA patients transported to Tsuyama Chuo Hospital from 2014 - 2017. We included cases with total body CT scan examined after ROSC or death. We excluded inter-facility transport and insertion of gastric tube before CT. We measured the total gastric volume using 3D imaging software (FUJIN Anatomia, AZE, Tokyo). Primary outcome: Comparison of gastric volume between patients with and without ROSC. Secondary outcome: Factors associated with increased gastric volume. Mann Whitney U-test was used for the primary outcome. Multivariable regression analysis was used for the secondary outcome. Results: 446 cases were included in the study. Median age was 79 [IQR: 68 - 86], 55% was male, 4% with initial rhythm VF/VT, 45% was estimated cardiac origin, 37% was witnessed arrest, 27% had ROSC. The total gastric volume was 400ml [192 - 793]. There was no difference in gastric volume between ROSC group and no-ROSC group (418 [232 - 733] vs 389 [183 - 824], p = 0.46). Airway management maneuver on arrival did not affect gastric volume (bag-valve-mask β: -99; 95% CI: -250 - 52, laryngeal tube β: -85; 95% CI: -228 - 59, endotracheal intubation: reference). Longer transport time was associated with increased the gastric volume (β: 5.6; 95% CI: 1.0 - 10) as was a non-cardiac origin of arrest (β: 121; 95% CI: 34 - 208). Conclusion: Abdominal distention was not associated with ROSC. Type of initial airway management did not significantly affect gastric volume. Factors associated with increased gastric volume at emergency department arrival were longer transportation time and non-cardiac origin of arrest.