具抵抗性高血壓和腎功能不良老人對propofol和笑氣麻醉有蘇醒緩慢現象－臨床病例分析

Propofol和笑氣麻醉對大多數病人具有降血壓和蘇醒快速的特點，但作者於150個案 中，却發現propofol若高劑量灌注於具抵抗性高血壓和腎功能欠佳之老病人時 ，術後蘇醒速度嚴重延緩，此高劑量平均為9.8mg/kg/h。若腎功能正常，而劑量於後 半期急降並使用抗高血藥劑維持正常血壓，則病人蘇醒快速。若病人之高血壓對 propofol反應敏銳，則不需抗高血壓劑，小量之propofol和笑氣即可維持麻醉和正常 血壓。腎功能正常與否並非絕對能定propofol之排泄速度，但年紀越大，propofol擴 清速度越慢。高劑量長期灌注propofol作為抗高血壓劑以維持正常血壓乃是病人蘇醒 緩慢之根本原因。 Propofol , nitrous oxide and oxygen anesthesia usually causes hypotension and early awakening is expected generally. However, the authors found a case of delayed awakening among 150 patients. The patient was an elder with poor renal function and sustained hypertension. Her blood pressure was controlled with prolonged high dose infusion (mean dose =9.8 mg/kg per h) of propofol. Two other cases in similar situation but recovered early from the anesthesia are included in this report for comparison. One of the two was an elderly patient with sustained hypertension but normal renal function, the dose of propofol was kept minimal and the blood pressure was controlled with antihypertensive agents during the last period of operation. The other patient was also an elder with hypertension and renal insufficiency, but the hypertension was very sensitive to propofol, adequate blood pressure and depth of anesthesia were maintained by low dose of propofol. The clearance of propofol is not influenced significantly by the renal function. But with aging, the clearance is reduced. Prolonged infusion of propofol in high dose to control sustained perioperative hypertension may cause delayed awakening