Transpulmonary cardiac output measurement in a rat model of cardiac arrest and CPR: impact of vascular access.

Abstract

OBJECTIVE: The present study investigated the impact of the vascular access site for cardiac output (CO) measurement by thermodilution on survival and neurohistopathological injury in a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Secondary the influence of the vascular access site on cardiac output measurements was examined. METHODS: Rats underwent asphyxial CA and CPR. Thermocouple probes were either placed via the femoral artery into the bifurcation of abdominal aorta/iliac artery (Femoral) or via the carotid artery into the aortic arch (Carotid). CPR was initiated after 9 min CA. Local cerebral blood flow (lCBF) and CO were assessed for 120 min after restoration of spontaneous circulation. Neurohistopathological injury was determined using Fluoro-Jade B staining. RESULTS: Survival was reduced in the Carotid group compared to the Femoral group (p<0.01). Fluoro-Jade B staining in the hippocampus showed no difference between CA groups. CO measurements were comparable between femoral and carotid artery access sites. lCBF revealed a delayed hyperperfusion in the Carotid group only. CONCLUSIONS: The present study demonstrates the influence of the vascular access site for placing thermocouple probes for CO measurement on animal survival after CA/CPR. CO did not differ between the two access sites with consequential different detection sites. Use of the femoral access for CO measurement is recommended for long-term survival after CA/CPR.