Irikura K, Miyasaka Y, Nagai S, Yuzawa I, Morii S, Fujii K
Department of Neurosurgery, Kitasato University School of Medicine, Kanagawa, Japan.
J Cereb Blood Flow Metab. 1998 Dec;18(12):1294-7. doi: 10.1097/00004647-199812000-00003.
Two types of acid-base strategies are available for the blood gas management of patients during hypothermia: alpha-stat and pH-stat management. However, the more suitable strategy for therapeutic hypothermia is unclear. We studied the effects of hypothermia (30 degrees C) and acid-base management on reactivity to hypercapnia and hypotension in rat pial arterioles, using a closed cranial window. The baseline diameter during hypothermia decreased in the alpha-stat (PaCO2 was maintained at 35 mm Hg when measured at 37 degrees C, n = 8), but not in the pH-stat (PaCO2 was maintained at 35 mm Hg when corrected to the animal's actual temperature, n = 7). Vasodilation induced by hypotension was significantly reduced in hypothermic groups compared with the normothermic group (n = 7), whereas responses to hypercapnia were preserved. Moreover, hypotensive vasodilation was more attenuated in the pH-stat, than the alpha-stat, management. These findings show that moderate hypothermia and acid-base management alter cerebrovascular autoregulation.
在低温期间，有两种酸碱策略可用于患者的血气管理：α-稳态和pH-稳态管理。然而，治疗性低温更合适的策略尚不清楚。我们使用封闭颅窗研究了低温（30摄氏度）和酸碱管理对大鼠软脑膜小动脉对高碳酸血症和低血压反应性的影响。低温期间的基线直径在α-稳态管理中减小（当在37摄氏度测量时，PaCO2维持在35 mmHg，n = 8），但在pH-稳态管理中未减小（当校正至动物实际体温时，PaCO2维持在35 mmHg，n = 7）。与正常体温组（n = 7）相比，低温组中低血压诱导的血管舒张显著降低，而对高碳酸血症的反应得以保留。此外，pH-稳态管理中低血压性血管舒张比α-稳态管理中更减弱。这些发现表明，中度低温和酸碱管理会改变脑血管自动调节。
