The aim of this study was to investigate the effect of changes in end-tidal carbon dioxide tension (ETCO2) during remifentanil (Remi) infusion on oral tissue blood flow in rabbits. Eight male tracheotomized Japan White rabbits were anesthetized with sevoflurane under mechanical ventilation. The infusion rate of Remi was 0.4 μg/kg/min. Carbon dioxide was added to the inspired gas to change the inspired CO2 tension to prevent changes in the ventilating condition. Observed variables were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), common carotid artery blood flow (CCBF), tongue mucosal blood flow (TBF), mandibular bone marrow tissue blood flow (BBF), masseter muscle tissue blood flow (MBF), upper alveolar tissue blood flow (UBF), and lower alveolar tissue blood flow (LBF). The CCBF, TBF, BBF, UBF, and LBF values were increased, while MBF was decreased, under hypercapnia, and vice versa. The BBF, UBF, and LBF values were increased, while the MBF value was decreased, under hypercapnia during Remi infusion, and vice versa. The BBF, MBF, UBF, and LBF values, but not the CCBF and TBF values, changed along with ETCO2 changes during Remi infusion.Abstract
Comparisons of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) during remifentanil (Remi) infusion with those during no Remi infusion. All variables were decreased during Remi infusion when compared under identical end-tidal carbon dioxide tension (ETCO2) level. The DBP level was increased and HR was decreased along with ETCO2 elevation during Remi infusion. Data are shown as mean ± SD (n = 8). *P < .05 versus respective values at ETCO2 30 mm Hg. #P < .05 between two values at the same ETCO2 level.
Comparisons of common carotid artery blood flow (CCBF), tongue mucosal blood flow (TBF), mandibular bone marrow tissue blood flow (BBF), upper alveolar tissue blood flow (UBF), lower alveolar tissue blood flow (LBF), and masseter muscle tissue blood flow (MBF) during remifentanil (Remi) infusion with those during no Remi infusion. All variables were decreased during Remi infusion when compared under identical end-tidal carbon dioxide tension (ETCO2) level. The BBF, UBF, and LBF values were increased and MBF was decreased along with ETCO2 elevation during Remi infusion. Data are shown as mean ± SD (n = 8). *P < .05 versus respective values at ETCO2 30 mm Hg. #P < .05 between 2 values at the same ETCO2 level.
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