Alfred P. Hallstrom

BACKGROUND: Despite extensive training of citizens of Seattle in cardiopulmonary resuscitation (CPR), bystanders do not perform CPR in almost half of witnessed cardiac arrests. Instructions in chest compression plus mouth-to-mouth ventilation given by dispatchers over the telephone can require 2.4 minutes. In experimental studies, chest compression alone is associated with survival rates similar to those with chest compression plus mouth-to-mouth ventilation. We conducted a randomized study to compare CPR by chest compression alone with CPR by chest compression plus mouth-to-mouth ventilation. METHODS: The setting of the trial was an urban, fire-department-based, emergency-medical-care system with central dispatching. In a randomized manner, telephone dispatchers gave bystanders at the scene of apparent cardiac arrest instructions in either chest compression alone or chest compression plus mouth-to-mouth ventilation. The primary end point was survival to hospital discharge. RESULTS: Data were analyzed for 241 patients randomly assigned to receive chest compression alone and 279 assigned to chest compression plus mouth-to-mouth ventilation. Complete instructions were delivered in 62 percent of episodes for the group receiving chest compression plus mouth-to-mouth ventilation and 81 percent of episodes for the group receiving chest compression alone (P=0.005). Instructions for compression required 1.4 minutes less to complete than instructions for compression plus mouth-to-mouth ventilation. Survival to hospital discharge was better among patients assigned to chest compression alone than among those assigned to chest compression plus mouth-to-mouth ventilation (14.6 percent vs. 10.4 percent), but the difference was not statistically significant (P=0.18). CONCLUSIONS: The outcome after CPR with chest compression alone is similar to that after chest compression with mouth-to-mouth ventilation, and chest compression alone may be the preferred approach for bystanders inexperienced in CPR.

The automatic external defibrillator is a simple device that can be used by nonprofessional rescuers to treat cardiac arrest. In 1287 consecutive patients with out-of-hospital cardiac arrest, we assessed the results of initial treatment with this device by firefighters who arrived first at the scene, as compared with the results of standard defibrillation administered by paramedics who arrived slightly after the firefighters. Of 276 patients who were initially treated by firefighters using the automatic defibrillator, 84 (30 percent) survived to hospital discharge (expected rate according to a logistic model, 17 percent; P less than 0.001), as compared with 44 (19 percent) of 228 patients when fire-fighters delivered only basic cardiopulmonary resuscitation and the first defibrillation was performed after the arrival of the paramedic team. Few patients with conditions other than ventricular fibrillation survived. In a multivariate analysis of characteristics that influenced survival after ventricular fibrillation, a better survival rate was related to a witnessed collapse (odds ratio, 3.9; 95 percent confidence interval, 2.0 to 7.6), younger age (odds ratio, 1.2; 95 percent confidence interval, 1.0 to 1.4), the presence of "coarse" (higher-amplitude) fibrillation (odds ratio, 4.2; 95 percent confidence interval, 1.6 to 11.0), a shorter response time for paramedics (odds ratio, 1.4; 95 percent confidence interval, 1.0 to 2.1), and initial treatment by firefighters using an automatic external defibrillator (odds ratio, 1.8; 95 percent confidence interval, 1.1 to 2.9). These findings support the widespread use of the automatic external defibrillator as an important part of the treatment of out-of-hospital cardiac arrest, although the overall impact of the use of this device on community survival rates is still uncertain.

The survival rate for patients with out-of-hospital cardiac arrest is low in communities where emergency service is provided solely by emergency medical technicians. We trained such technicians in a suburban community of 79,000 to recognize and treat out-of-hospital ventricular fibrillation with up to three defibrillatory shocks without the use of medications or special airway protection. Outcomes from cardiac arrest due to underlying heart disease were determined during two periods: two years with standard care by emergency medical technicians and one year with defibrillator-trained technicians. During the period with standard care, four of 100 patients with cardiac arrest were resuscitated and discharged alive from the hospital, as compared with 10 of 54 patients during the period with defibrillator-trained technicians (P less than 0.01). In 12 of 38 patients with ventricular fibrillation, a stable perfusing cardiac rhythm followed defibrillatory shocks given by defibrillator technicians. The enhanced survival after cardiac arrest is encouraging, and further trials of defibrillation by emergency medical technicians are warranted.