Abstract 3: The Survival Rate from Out-of-Hospital Cardiac Arrest is Superior with Passive Oxygen Insufflation Compared to Active Assisted Ventilation
OBJECTIVE: Experimental evidence suggests that excessive volume and rates of positive pressure ventilation during resuscitative efforts for out-of-hospital cardiac arrests (OOHCA) may be deleterious. The optimal ventilation technique for OOHCA, including method, timing, rate, and tidal volume have not been determined. We sought to compare survival rates for adults with OOHCA receiving cardiocerebral resuscitation (CCR) between those receiving passive oxygen insufflation and those receiving oxygen via active bag-valve-mask (BVM) ventilation.
METHODS: The Save Hearts in Arizona Registry and Education (SHARE) program collected Utstein style data on consecutive adults with OOHCA from 11 different fire departments in Arizona utilizing CCR between May 2005 and December 2006. Passive insufflation was defined as an oro-pharyngeal airway device, and high flow oxygen at 15 L/min provided via a non-rebreather facemask without assisted ventilation while active ventilation was defined as BVM ventilation by paramedics at a recommended rate of 8/minute. The primary outcome was survival to hospital discharge in all arrests and for the subgroup with witnessed ventricular fibrillation (VF). Outcomes were obtained from the Office of Vital Statistics as well as local hospitals and were compared using chi square testing; alpha = 0.05.
RESULTS: 442 adult OOHCAs received CCR and were consecutively enrolled. Standard characteristics did not differ between the passive insufflation and active ventilation groups. 142/442 (32%) received passive insufflation and 300/442 (68%) received BVM ventilation. Overall survival did not differ between the passive insufflation group and the active ventilation group (12.7% (18/142) vs. 8% (24/300), p > 0.05). Survival for witnessed VF was significantly higher in the passive insufflation group compared to the active ventilation group (48.6% (17/35) vs. 20.0% (12/60), p < 0.01). The odds of survival was 7.2 times higher in the passive insufflation group when compared to the active ventilation group (95% CI 2.4,21.6).
CONCLUSION: The survival rate of adults with witnessed VF OOHCA was superior in victims receiving passive oxygen insufflation than in victims receiving active ventilation during cardiocerebral resuscitation.