The aim of this study was to investigate the effect of remifentanil infusion on oral
tissue blood flow including submandibular gland tissue blood flow (SBF) and internal
carotid artery blood flow (ICBF) in rabbits during sevoflurane anesthesia. Twelve male
Japan White rabbits were anesthetized with sevoflurane and remifentanil. Remifentanil was
infused at 0.2 and 0.4 µg/kg/min. Measurements included circulatory
variables, common and external carotid artery blood flow (CCBF, ECBF), ICBF, tongue
mucosal blood flow (TMBF), masseter muscle tissue blood flow (MBF), mandibular bone marrow
tissue blood flow (BBF), tongue muscle tissue blood flow (TBF) and SBF. Vascular
resistances for each tissue, including the tongue mucosa, masseter muscle, mandibular bone
marrow, tongue muscle and submandibular gland, were calculated by dividing the mean
arterial pressure by the respective tissue blood flow. Remifentanil infusion decreased
oral tissue blood flow and circulatory variables. CCBF, ECBF and ICBF did not change. The
calculated vascular resistance in each oral tissue, except for the tongue mucosa,
increased in an infusion-rate-dependent manner. These results showed that remifentanil
infusion reduced TMBF, MBF, BBF, TBF and SBF in an infusion-rate-dependent manner without
affecting ICBF under sevoflurane anesthesia.