Abstract 8: Influence of Receiving Hospital Characteristics on Survival after Cardiac Arrest

Hospital management of out-of-hospital cardiac arrest (OHCA) patients after return of spontaneous circulation (ROSC) can influence patient survival via interventions such as hypothermia and cardiac catheterization (CATH). This study tested the hypothesis that survival differed between different types of hospitals for subjects with ROSC after OHCA. Methods: Adult (≥ 18 years) subjects with paramedic-documented ROSC or who lived &gt;1 day after OHCA were identified with their receiving hospital in a prospective database from 9 regions in the US and Canada. Hospitals were characterized using the American Hospital Directory or the Guide to Canadian Healthcare Facilities. Hospitals were categorized by bed number (large &gt;400; medium 250 – 400; small &lt;250) and CATH capability. Associations between clinical variables, hospital categories, survival time, and survival to hospital discharge were determined using Cox regression and analysis of variance. Results: Between December 2005 and July 2007, 3644 OHCA subjects were treated in 254 hospitals, with similar numbers in large (1026), medium (1094) and small (1276) hospitals. CATH hospitals treated 2123 (58%) subjects, and patient features (63% male, 42% VF/VT, 67% witnessed collapse, and mean call-arrival interval of 5.7 (SD 2.8) minutes) did not differ between hospital categories. CATH hospitals had higher survival than non-CATH hospitals in large (35.1% vs. 27.7%), medium (34.4% vs. 30.7%) and small (38.6% vs. 26.5%) categories (F=19.55; p&lt;0.001). VF/VT (p &lt; 0.001), age (p &lt; 0.001) and witnessed collapse (p &lt; 0.001) were associated with survival time. When adjusted for initial rhythm, call-arrival interval, witnessed collapse, age, sex, region, teaching institution, and trauma center level, there was no significant effect of CATH. However, the interaction of large hospital and CATH was associated with lower hazard of death (0.71, 95% CI [0.54, 0.93]). Conclusions: Transport to a CATH hospital is associated with increased probability of survival to discharge after OHCA. These data cannot determine whether cardiac catheterization was performed or if CATH hospital is a surrogate for more comprehensive cardiac care. Therefore, further work should examine what aspects of in-hospital care affected outcome.</jats:p

Abstract 236: Regional Incidence and Outcome of Out-of-Hospital Cardiac Arrest Associated with Overdose

Introduction: The frequency of lethal overdose due to prescription and non-prescription drugs is increasing in North America. The contribution of drug overdose (OD) to regional variation in the incidence and outcome out-of-hospital cardiac arrest (OHCA) is unclear. Objective: To estimate overall and regional variation in incidence and outcomes of emergency medical services (EMS)-treated OD-OHCA cases across North America. Methods: The Resuscitation Outcomes Consortium (ROC) is a clinical research network with 10 regional clinical centers in United States (US) and Canada that uses uniform methods for surveillance of all EMS-treated OHCA in participating regions. Cases of OHCA from 2006 to 2010 were reviewed for evidence of association with or without OD. Incidence of OD-OHCA was calculated as the number of OD-OHCA in a region per 100,000 cumulative person-years, using 2000 US Census and 2006 Statistics Canada population counts. Patient and EMS characteristics as well as outcome were described. Multiple logistic regression was used to describe the association between OD status on return of spontaneous circulation (ROSC) and survival to hospital discharge, while adjusting for case characteristics and consortium center. Results: Included were 56,272 cases of OHCA. Regional incidence of OD-OHCA varied between 0.5 and 2.7 per 100,000 person years (p&lt;0.001), and proportion of OD-OHCA among all EMS-treated OHCA ranged from 0.9% to 3.8%. Table 1 shows outcomes and characteristics stratified by OD status; OD-OHCA were younger, less likely to be witnessed, and less likely to present with a shockable rhythm. Compared to non-OD, OD-OHCA was associated with ROSC (OR: 1.55; 95%CI: 1.35-1.78) and survival (OR: 2.14; 95%CI: 1.72-2.65). Conclusions: OD-OHCA are a small proportion of all OHCA, although incidence varied up to 5-fold across regions. OD-OHCA were more likely to survive than non-OD-OHCA. </jats:p