Sazuka Shoichiro, Matsuura Nobuyuki, Ichinohe Tatsuya
Department of Dental Anesthesiology, Tokyo Dental College, Chiba, Japan.
J Oral Maxillofac Surg. 2012 Aug;70(8):1808-14. doi: 10.1016/j.joms.2012.02.022. Epub 2012 May 24.
The aim of the present study was to investigate the effect of dexmedetomidine (DEX) continuous infusion on blood flow in rabbit oral tissues during sevoflurane or propofol anesthesia.
A total of 24 male tracheotomized Japanese white rabbits were anesthetized with sevoflurane or propofol under mechanical ventilation. An initial loading dose of 6.0 μg/kg/hr DEX was administered for 10 minutes. DEX was then maintained at 0.2, 0.4, and 0.6 μg/kg/hr for 1 hour, respectively. The observed variables were systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, 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), lower alveolar tissue blood flow (LBF), and vascular resistance for each tissue (tongue mucosal vascular resistance, mandibular bone marrow vascular resistance, masseter muscle vascular resistance, upper alveolar tissue vascular resistance, and lower alveolar tissue vascular resistance).
The heart rate, systolic blood pressure, mean arterial pressure, common carotid artery blood flow, TBF, BBF, MBF, UBF, and LBF showed dose-dependent decreases during DEX infusion during both sevoflurane and propofol anesthesia. The decreasing ratios in TBF, BBF, MBF, UBF, and LBF were greater than those in heart rate, systolic blood pressure, mean arterial pressure, and common carotid artery blood flow. The vascular resistance of the oral tissues was increased in a dose-dependent manner during DEX infusion in both sevoflurane and propofol anesthesia.
Our findings suggest that infusion of DEX decreases TBF, BBF, MBF, UBF, and LBF in a dose-dependent manner without significant changes in systemic hemodynamic variables during sevoflurane or propofol anesthesia.
本研究旨在探讨在七氟醚或丙泊酚麻醉期间持续输注右美托咪定（DEX）对兔口腔组织血流的影响。
将24只雄性气管切开的日本白兔在机械通气下用七氟醚或丙泊酚麻醉。先以6.0μg/kg/hr的初始负荷剂量输注DEX 10分钟。然后分别以0.2、0.4和0.6μg/kg/hr的剂量维持输注1小时。观察的变量包括收缩压、舒张压、平均动脉压、心率、颈总动脉血流量、舌黏膜血流量（TBF）、下颌骨骨髓血流量（BBF）、咬肌血流量（MBF）、上牙槽组织血流量（UBF）、下牙槽组织血流量（LBF）以及各组织的血管阻力（舌黏膜血管阻力、下颌骨骨髓血管阻力、咬肌血管阻力、上牙槽组织血管阻力和下牙槽组织血管阻力）。
在七氟醚和丙泊酚麻醉期间输注DEX时，心率、收缩压、平均动脉压、颈总动脉血流量、TBF、BBF、MBF、UBF和LBF均呈剂量依赖性下降。TBF、BBF、MBF、UBF和LBF的下降比例大于心率、收缩压、平均动脉压和颈总动脉血流量的下降比例。在七氟醚和丙泊酚麻醉期间输注DEX时，口腔组织的血管阻力均呈剂量依赖性增加。
我们的研究结果表明，在七氟醚或丙泊酚麻醉期间，输注DEX可使TBF、BBF、MBF、UBF和LBF呈剂量依赖性下降，而全身血流动力学变量无明显变化。
