Mild induced hypothermia and survival after out-of-hospital cardiac arrest in a Swedish urban area

Background: Mild induced hypothermia (MIH) was introduced for post cardiac arrest care in Sweden in 2003, based on two clinical trials. This retrospective study evaluated its association with 30-day survival after out-of-hospital cardiac arrest (OHCA) in a Swedish community from 2003 to 2015. Methods: Out of 3680 patients with OHCA, 1100 were hospitalized after return of spontaneous circulation and 871 patients who remained unconscious were included in the analysis. Prehospital data were extracted from the Swedish Registry of Cardiopulmonary Resuscitation and in-hospital data were extracted from clinical records. Propensity score analysis on complete data sets and multivariable logistic regression with multiple imputations to compensate for missing data were performed. Results: Unadjusted 30-day survival was 23.5%; 37% in 386/871 (44%) MIH treated and 13% in 485/871 (56%) non-MIH treated patients. Unadjusted odds ratio (OR) for 30-day survival in patients treated with MIH compared to non-MIH treated patients was 3.79 (95% CI 2.71-5.29; p. <. 0.0001). Using stratified propensity score analysis and in addition adjusting for in-hospital factors, 30-day survival was not significantly different in patients treated with MIH compared to non-MIH treated patients; OR 1.33 (95% CI 0.83-2.15; p = 0.24). Using multiple imputations to handle missing data yielded a similar adjusted OR of 1.40 (95% CI 0.88-2.22; p = 0.15). Good neurologic outcome at hospital discharge was seen in 82% of patients discharged alive. Conclusion: Treatment with MIH was not significantly associated with increased 30-day survival in patients remaining unconscious after OHCA when adjusting for potential confounders

Early predictors of poor outcome after out-of-hospital cardiac arrest

Abstract Background Early identification of predictors for a poor long-term outcome in patients who survive the initial phase of out-of-hospital cardiac arrest (OHCA) may facilitate future clinical research, the process of care and information provided to relatives. The aim of this study was to determine the association between variables available from the patient’s history and status at intensive care admission with outcome in unconscious survivors of OHCA. Methods Using the cohort of the Target Temperature Management trial, we performed a post hoc analysis of 933 unconscious patients with OHCA of presumed cardiac cause who had a complete 6-month follow-up. Outcomes were survival and neurological function as defined by the Cerebral Performance Category (CPC) scale at 6 months after OHCA. After multiple imputations to compensate for missing data, backward stepwise multivariable logistic regression was applied to identify factors independently predictive of a poor outcome (CPC 3–5). On the basis of these factors, a risk score for poor outcome was constructed. Results We identified ten independent predictors of a poor outcome: older age, cardiac arrest occurring at home, initial rhythm other than ventricular fibrillation/tachycardia, longer duration of no flow, longer duration of low flow, administration of adrenaline, bilateral absence of corneal and pupillary reflexes, Glasgow Coma Scale motor response 1, lower pH and a partial pressure of carbon dioxide in arterial blood value lower than 4.5 kPa at hospital admission. A risk score based on the impact of each of these variables in the model yielded a median (range) AUC of 0.842 (0.840–0.845) and good calibration. Internal validation of the score using bootstrapping yielded a median (range) AUC corrected for optimism of 0.818 (0.816–0.821). Conclusions Among variables available at admission to intensive care, we identified ten independent predictors of a poor outcome at 6 months for initial survivors of OHCA. They reflected pre-hospital circumstances (six variables) and patient status on hospital admission (four variables). By using a simple and easy-to-use risk scoring system based on these variables, patients at high risk for a poor outcome after OHCA may be identified early