PetCO2, VCO2 and CorPP Values in the Successful Prediction of the Return of Spontaneous Circulation: An Experimental Study on Unassisted Induced Cardiopulmonary Arrest.

Abstract

INTRODUCTION: During cardiac arrest, end-tidal CO(PetCO), VCOand coronary perfusion pressure fall abruptly and tend to return to normal levels after an effective return of spontaneous circulation. Therefore, the monitoring of PetCOand VCOby capnography is a useful tool during clinical management of cardiac arrest patients. OBJECTIVE: To assess if PetCO, VCOand coronary perfusion pressure are useful for the prediction of return of spontaneous circulation in an animal model of cardiac arrest/cardiopulmonary resuscitation treated with vasopressor agents. METHODS: 42 swine were mechanically ventilated (FiO=0.21). Ventricular fibrillation was induced and, after 10 min, unassisted cardiac arrest was initiated, followed by compressions. After 2 min of basic cardiopulmonary resuscitation, each group received: Adrenaline, Saline-Placebo, Terlipressin or Terlipressin + Adrenaline. Two minutes later (4min of cardiopulmonary resuscitation), the animals were defibrillated and the ones that survived were observed for an additional 30 min period. The variables of interest were recorded at the baseline period, 10 min of ventricular fibrillation, 2min of cardiopulmonary resuscitation, 4min of cardiopulmonary resuscitation, and 30 min after return of spontaneous circulation. RESULTS: PetCOand VCOvalues, both recorded at 2 min and 4 min of cardiopulmonary resuscitation, have no correlation with the return of spontaneous circulation rates in any group. On the other hand, higher values of coronary perfusion pressure at the 4th min of cardiopulmonary resuscitation have been associated with increased return of spontaneous circulation rates in the adrenaline and adrenaline + terlipressin groups. CONCLUSION: Although higher values of coronary perfusion pressure at the 4th min of cardiopulmonary resuscitation have been associated with increased return of spontaneous circulation rates in the animals that received adrenaline or adrenaline + terlipressin, PetCOand VCOhave not been shown to be useful for predicting return of spontaneous circulation rates in this porcine model.