Effect of diabetes and pre-hospital blood glucose level on survival and recovery after out-of-hospital cardiac arrest

Objective: Diabetes mellitus and blood glucose level (BGL) are emerging as important prognosticators of outcome in critically ill patients. We evaluated the effect of diabetes and pre-hospital BGL on survival to hospital discharge and on 12-month functional recovery after out-of-hospital cardiac arrest (OHCA). Design, setting and participants: We performed a retrospective analysis of data from a statewide cardiac arrest registry in Victoria, Australia. We included 11 873 adult patients who had had an OHCA of presumed cardiac aetiology between 1 January 2007 and 30 June 2015. Of these, 2438 (20.5%) had documented diabetes. Main outcome measures: Survival to hospital discharge and 12-month functional recovery, measured using the Extended Glasgow Outcome Scale. Results: Crude survival to hospital discharge differed among patients with and without diabetes (6.8% v 13.4%; P < 0.001). Diabetes significantly reduced the odds of survival to hospital discharge for patients presenting with a shockable rhythm (adjusted odds ratio [OR], 0.57; 95% CI, 0.38-0.86; P = 0.007) and reduced the odds of good 12-month functional recovery for patients discharged alive (OR, 0.57; 95% CI, 0.35-0.95; P = 0.03). In contrast, a mild-to-moderate elevation of pre-hospital BGL (8.0- 15.9 mmol/L) was present in 695 of 1319 patients with available data (52.7%) and was associated with improved survival and functional recovery outcomes, which were independent of diabetes status. Conclusions: Diabetes affects at least one in five patients who have had an OHCA and is associated with poorer survival and 12-month functional recovery after OHCA. In comparison, an elevated pre-hospital BGL is common in the peri-arrest period and may be associated with improved outcomes.