Author Block:

Gordon A Ewy, Ronald W Hilwig, Karl B Kern, Arthur B Sanders, Melinda M Hayes, Charles W Otto, Robert A Berg, Univ of Arizona, Tucson, AZ

Disclosure Block:

 G.A. Ewy, None; R.W. Hilwig, None; K.B. Kern, None; A.B. Sanders, None; M.M. Hayes, None; C.W. Otto, None; R.A. Berg, None.

Abstract Body:

Background: Bystander CPR is crucial to optimizing long-term neurologically-intact survival following out-of-hospital cardiac arrest (OOH CA). The 2005 AHA/ILCOR Guidelines recommend a new compression to ventilation ratio of 30:2 to increase the circulatory support by increasing the number of compressions delivered during bystander CPR. Previous studies have shown that single lay rescuers interrupt chest compressions for an average of 16 sec each time they attempt the required 2 mouth-to-mouth breaths. We studied the hypothesis that such interruptions would compromise 24-hr neurologically-intact survival compared to continuous chest compressions (CCC). Methods: Domestic swine (25±5 kg; n=28) were anesthetized, instrumented, and electrically fibrillated. Mimicking an OOH CA, 3 min of VF then 9 min of bystander CPR or 4 min of VF and 8 min of bystander CPR were performed. Animals were randomized to receive simulated bystander CPR with either 30:2 (with 16 sec interruption of CC for the delivery of 2 breaths) or continuous chest compression (without interruption or assisted ventilation). ACLS including defibrillation was provided after 12 minutes of CA. All resuscitated animals were assessed for neurological function at 24 hours. Results: No significant difference in outcome was found between the two different forms of bystander CPR.

Conclusion: This study found no difference in normal neurological function at 24 hours with either form of bystander CPR prior to the use of ACLS. Preference should be given to the technique that best encourages bystander willingness to begin resuscitation efforts prior to the arrival of the professional EMS providers.