The deleterious effects of positive pressure ventilation may be prevented by substituting passive oxygen insufflation during advanced cardiac life support (ACLS) cardiopulmonary resuscitation (CPR).We compared 24-h neurologically normal survival among three different ventilation scenarios for ACLS in a realistic swine model of out-of-hospital prolonged ventricular fibrillation (VF) cardiac arrest. No bystander CPR was provided during the first 8min of untreated VF before the simulated arrival of an emergency medical system (EMS). Thirty-six swine were randomly assigned to one of three experimental groups. Group I (standard ventilation) was mechanically ventilated at 10 respirations per minute (RPM) at a tidal volume (TV) of 10ml/kg with 100% oxygen. Group II (hyperventilation) was ventilated at 35RPM at a TV of 20ml/kg with 100% oxygen. In Group III (insufflation) animals, a nasal cannula was placed in the oropharynx to administer oxygen continuously at 10l/min.There was no significant difference in the 24h neurologically normal survival among groups (standard: 2/12, hyperventilation: 2/12, insufflation: 4/12; p=.53).Passive insufflation may be an acceptable alternative to the currently recommended positive pressure ventilation during resuscitation efforts for out-of-hospital VF cardiac arrest. Potential advantages of this technique include: (1) easier to teach, (2) easier to administer, (3) prevention of the adverse effects of positive pressure ventilation and (4) allows EMS personnel to concentrate upon other critically important duties.