Resuscitation from cardiac arrest: assessment of a system providing only basic life support outside of hospital.

Resuscitation outside of hospital of victims of cardiac arrest is a major challenge to our emergency care system. Most cities in Canada do not have a mobile advanced life support service; instead they rely on basic life support outside of hospital. The outcome in such cases and the factors affecting the outcome are largely unknown. Thus, it is difficult to estimate the lifesaving potential of adding advanced life support to the existing measures available for care outside of hospital.A prospective study of all resuscitation attempts begun outside of hospital was conducted during 18 consecutive months in 1977-78 in Winnipeg; at that time only basic life support was available outside of hospital. Resuscitation was attempted 849 times, and 33 patients (4%) survived to be discharged from hospital. Data analysis revealed that: (a) none of the 58% of patients in asystole at the time of arrival at a hospital survived to be discharged, but 11% of the patients with ventricular fibrillation or tachycardia (27% of the entire group) survived; (b) the survival rate was lower when the interval from the emergency telephone call to the patient's arrival at the hospital exceeded 10 minutes; and (c) basic life support was begun immediately in 29% of the patients with ventricular fibrillation or tachycardia, and increased the survival rate fivefold.The training of private citizens in basic life support is a vital component of total emergency cardiac care. A mobile advanced life support service will be effective in saving lives if it reduces the delay before definitive care is instituted, preferably to less than 10 minutes.