Abstract P114: Higher Pulse-oximetry Values are Associated with Greater Hemodynamics During Cpr And Success of Resuscitation
Objectives. The use of peripheral pulse-oximetry during CPR has been controversial. We investigated peripheral oxygen saturation (SpO2) as an indicator of blood flow generated during CPR in a porcine model of cardiac arrest and resuscitation. We hypothesized that SpO2 measured with peripheral pulse-oximetry would be an indicator of forward blood flow generated by CPR and therefore predict the success of resuscitation.
Materials and methods. 19 domestic male pigs, weighing 40 ± 2 kg, were anesthetized, endotracheal intubated and mechanically ventilated. The right femoral artery and vein were cannulated and SpO2 was measured with an external pulse-oximeter (Masimo SET, Masimo Corp., CA) applied in the right ear. Ventricular fibrillation (VF) was electrically induced and untreated for 7 min. CPR, including mechanical chest compression and ventilation with oxygen with a compression/ventilation ratio of 30:2, was then performed for 4 min prior to defibrillation.
Results. 11 animals were successfully resuscitated. SpO2 decreased from baseline value of 98% ± 2 to 0 during VF. CPR increased SpO2 to an average value of 50% over the 4 min interval (p<0.01). SpO2 was significantly greater in animals in which CPR generated greater coronary perfusion pressures (CPP) and that were resuscitated compared to those that were not (Figure⇓).
Conclusions. Higher values of SpO2 were observed in animals in which CPR produced greater CPP and that were successfully resuscitated, compared to those in which CPR produced lower CPP and return of spontaneous circulation was not achieved. Pulse-oximetry is simple to use and provides additional information regarding the quality of CPR.