Low chance of survival among patients requiring adrenaline (epinephrine) or intubation after out-of-hospital cardiac arrest in Sweden

Abstract

Aim: To relate the outcome of out-of-hospital cardiac arrest to whether medication with adrenaline (epinephrine) was given and whether patients were intubated.

Patients: A national survey in Sweden between 1990-1995 among patients suffering out-of-hospital cardiac arrest and in whom resuscitation was attempted. Sixty per cent of ambulance organisations in Sweden participated.

Design: Prospective evaluation. Survival was defined as survival 1 month after cardiac arrest.

Results: In all, 14065 patients were included in the evaluation. Of these, resuscitation was attempted in 10966 cases. Among these adrenaline (epinephrine) was given in 42.4 and 47.5% were intubated. In an univariate analysis treatment with adrenaline (epinephrine) and intubation was associated with a lower survival when all patients were evaluated. In a multivariate analysis including age, sex, place of arrest, bystander-CPR, initial arrhythmia, arrest being witnessed and aetiology, treatment with adrenaline (epinephrine) (OR 0.43, CI 0.27-0.66) and intubation (OR 0.71, CI 0.51-0.99) were both independent predictors of a lower chance of survival. When separately analysing patients with bystander witnessed cardiac arrest found in ventricular fibrillation and requiring more than 3 defibrillatory shocks neither treatment with adrenaline (epinephrine) nor intubation was associated with survival. Among patients with a non-shockable rhythm treatment with adrenaline (epinephrine) was a significant independent predictor for lower survival (OR 0.30, CI 0.07-0.82).

Conclusion: In a national survey in Sweden including 10966 cases of out-of-hospital cardiac arrest the outcome was related to whether medication with adrenaline (epinephrine) was given and whether patients were intubated. Neither in total nor in any subgroup did we find results indicating beneficial effects of any of these two interventions. Whether treatment with adrenaline (epinephrine) or intubation will increase survival after out-of-hospital cardiac arrest needs to be confirmed in prospective randomised trials.