Kellum MJ, Kennedy KW, Ewy GA: Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest. American Journal of Medicine. 2006. 119(4):335–340.
A paramedic service in my home state of Wisconsin, along with two services in Tucson, Ariz., elected to study the effect of compression only CPR in witnessed cardiac arrest. All patients had an oral airway placed and 100 percent oxygen applied by non-rebreather mask. Artificial ventilations were withheld until three rounds (two minutes of 100 compression/min) of CPR along with AED if in a shockable rhythm or return of spontaneous circulation. Two minutes of CPR was performed before AED use, and only one shock was administered at a time, which was then followed by immediate CPR. Prior to the study, 19 percent of patients with witnessed cardiac arrests found in a shockable rhythm survived. Following implementation of the new protocols, 57 percent survived.
This is the first cardiac arrest outcomes study using anything similar to the new AHA 2005 guidelines. The decision to defer ventilations is consistent with what many feel to be the circulatory phase of cardiac arrest, during which the primary goal is to promote coronary and cerebral artery perfusion with effective chest compression. Studies demonstrate that artificial ventilations impede perfusion in this phase of cardiac arrest, speculated to be from four to 10 minutes after collapse, which is when the majority of EMS arrivals occur. Now that the 2005 AHA guidelines are being taught, it will be interesting to see if these results can be duplicated.