Characteristics and outcome among patients suffering from out of hospital cardiac arrest of non-cardiac aetiology

Abstract

Aim: To describe the epidemiology for out of hospital cardiac arrest of a non-cardiac aetiology. Patients: All patients suffering from out of hospital cardiac arrest in whom resuscitation efforts were attempted in the community of Göteborg between 1981 and 2000. Methods: Between October 1, 1980 and October 1, 2000, all consecutive cases of cardiac arrest in which the emergency medical service (EMS) system responded and attempted resuscitation were reported and followed up to discharge from hospital. Results: In all, 5415 patients participated in the evaluation. Among them 1360 arrests (25%) were judged to be of a non-cardiac aetiology. Among these 24% were caused by a surgical cause or accident, 20% by obstructive pulmonary disease, 13% by drug abuse and the remaining 43% by ‘another cause’. Of the patients with out of hospital cardiac arrest of a non-cardiac aetiology 4.0% survived to discharge from hospital as compared with 10.1% of the patients with a cardiac aetiology ( P<0.0001). In the various subgroups survival was highest in those with drug abuse (6.8%) and lowest in those with ‘another cause’ (4.2%). Cerebral performance categories (CPC) score at hospital discharge tended to be worse among survivors from an arrest of non-cardiac than cardiac aetiology. Patients with a cardiac arrest of a non-cardiac aetiology differed from the remaining patients by being younger, including more women, less frequently having a witnessed arrest and less frequently being found in ventricular fibrillation/tachycardia. When simultaneously considering age, sex, witnessed status, presence of bystander cardiopulmonary resuscitation (CPR) and initial arrhythmia, the aetiology (non-cardiac vs. cardiac aetiology) was not an independent predictor of survival. Conclusion: Among patients with out of hospital cardiac arrest in whom resuscitation was attempted 25% were judged to be of a non-cardiac aetiology. These patients had a lower survival than patients with a cardiac arrest of cardiac aetiology. However, this was mainly explained by a lower occurrence of ventricular fibrillaltion and witnessed cardiac arrest.