Dose-Dependent Remifentanil Decreases Oral Tissue Blood Flow During Sevoflurane and Propofol Anesthesia in Rabbits

Abstract

The aim of this study was to investigate the effect of remifentanil continuous infusion on the blood flow in rabbit oral tissue during propofol and sevoflurane anesthesia, as well as its dose dependency. Sixteen male tracheotomized Japan white rabbits were anesthetized with propofol or sevoflurane under mechanical ventilation. The infusion rate of remifentanil was 0.1, 0.2, 0.4, 0.8, and 1.6 μg·kg(-1)·min(-1), respectively, for 20 minutes. Observed variables were systolic blood pressure (SBP), diastolic blood pressure, mean arterial pressure (MAP), heart rate (HR), common carotid artery blood flow, tongue mucosal blood flow (TBF), mandibular bone marrow blood flow (BBF), masseter muscle blood flow (MBF), upper alveolar tissue blood flow (UBF), and lower alveolar tissue blood flow (LBF). HR, SBP, MAP, TBF, BBF, MBF, UBF, and LBF showed dose-dependent decreases during remifentanil infusion with both propofol and sevoflurane anesthesia. The decreases in BBF, MBF, UBF, and LBF explained as a percent change were greater than those in HR, SBP, MAP, and TBF. In the sevoflurane group, there were no changes in diastolic blood pressure and common carotid artery blood flow during remifentanil infusion. Our findings suggest that infusion of remifentanil reduces TBF, BBF, MBF, UBF, and LBF in a dose-dependent manner without a significant reduction in MAP during propofol and sevoflurane anesthesia.