Open chest selective aortic arch perfusion vs open cardiac massage as a means of perfusion during in exsanguination cardiac arrest: a comparison of coronary hemodynamics in swine

Aim: To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine. Methods: Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5 min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1 min of OCSAAP at a rate of 10 mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared. Results: At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP > 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP. Conclusion: OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT).