Abstract
In Japan the survival rate for patients with out-of-hospital cardiopulmonary arrest cases is very low, because emergency personnel are not permitted to perform advanced life support measures. In this study we investigated cardiac rhythm at the emergency scene, witnessed vs unwitnessed arrest, restoration of heart beat, duration of arrest, and blood chemistry of patients with out-of-hospital cardiac arrest in an attempt to determine what can be done to increase the resuscitation rate for such patients. Electrocardiograms (ECG) at the emergency scene were obtained in 131 patients (mean age 63.2yr) seen in our emergency room over the past 9 months. Fifty-four (41.2%) of these patients suffered acute cardiac arrest that occurred suddenly without other symptoms. Ventricular fibrillation (Vf) detected in was 29% and asystole in 42% at the emergency scene. On ECG upon admission Vf had decreased to 19.8% and asystole had increased to 49%; moreover, 4 patients (15.4%) with Vf and 14 patients (21.3%) with asystole regained a palpable pulse in the emergency room. Among patients with electromechanical dissociation, there were a large number of witnessed arrests, so the restoration rate was high. Of 40 patients (30.5%) who regained a spontaneous pulse, 10 (7.6%) had already regained it before arrival at the hospital; 8 (6.1%) died in the emergency room. Of the remaining 32 patients, who were admitted to the hospital, only 4 (3.1%) recovered consciousness, but of these 4, 3 had regained their pulse before arrival. Only 5 patients (3.8%) received bystander CPR; among them, the restoration rate was high (60%). The time from cardiac arrest to initiation of basic life support measures was significantly shorter for patients who regained their pulse before hospital arrival (p<0.02). Duration of CPR was also shorter in patients who regained their pulse. Serum potassium and base excess were also significantly lower in patients who regained their pulse (p<0.05). Duration of arrest probably influences serum potassium and base excess, so these data may provide us with clues to the likelihood of resuscitation. We conclude that to improve the resuscitation rate advanced life support measures, especially defibrillatory shock, must be performed by emergency personnel when needed. Moreover, it is necessary to increase CPR training of the public.
