Physio-pharmacological effects of intravenous anesthetic agent ; Propofol on respiratory depression

在第一年，我们比较了异丙酚和七氟醚麻醉对肾功能正常的ASA分级I级和II级患者尿酸(UA)排泄的影响。异丙酚组(n=11)在异丙酚麻醉诱导后注入异丙酚-一氧化二氮-芬太尼，七氟醚组(n=12)在硫代戊醛麻醉诱导后注入七氟醚-一氧化二氮-芬太尼。分别于麻醉诱导前、麻醉诱导后1、2、3h及术后第1天测定血尿酸、肌酐、尿尿素氮浓度。同时检测N-乙酰-β-D-氨基葡萄糖苷酶、β_2-微球蛋白浓度和尿液pH值。计算尿酸(CUA)和肌酐(Ccr)的血浆清除率。尿尿酸的小时浓度和排泄量均显著高于七氟醚。每小时尿量与尿酸浓度之间存在显著的相关性。异丙酚组的CUA明显高于七氟醚组。在其他肾脏变量上，两组之间没有显著差异。这项研究表明，异丙酚麻醉时尿酸排泄增加，而七氟醚麻醉时尿酸排泄保持稳定。第二年，我们观察了异丙酚和硫柳汞对26名成年志愿者吞咽反射的影响。分别用异丙酚(P组，n=16)或硫代戊醛(T组，n=10)镇静。咽腔内注入蒸馏水0.25、0.5、0.75和1.0mL，通过硬膜外导管诱导吞咽。根据燕子的数量和反应的潜伏期来分析对注射水的反应。F组大鼠的吞咽潜伏期延长，吞咽次数减少，而T组则无明显变化。提示异丙酚对吞咽反射的抑制作用强于硫柳汞。

In the first year, we compared the effect of propofol with that of sevoflurane anesthesia on uric acid (UA) excretion in ASA physical status I and II patients with normal renal function. A propofol group (n=11) received propofol-nitrous oxide-fentanyl after induction of anesthesia by propofol while a sevoflurane group (n= 12) received sevoflurane-nitrous oxide-fentanyl after induction of anesthesia by thiamylal. UA, creatinine (Cr), and urea nitrogen concentrations in serum and urine were measured before induction of anesthesia, 1, 2, and 3h after induction, and at 1 postoperative day. N-acety1-beta-D-glucosaminidase, beta_2-microglobulin concentrations and pH in urine were also examined. Plasma clearance of UA (CUA) and Cr (CCr) were calculated. The hourly concentration and excretion of urine UA were significantly higher than those of the sevoflurane. Significant correlations were noted between the hourly urine volume and UA concentration. The CUA of the propofol group was significantly higher than that of the sevoflurane group. There were no significant differences in other renal variables between the two groups. This study demonstrated that the UA excretion increased during propofol anesthesia, while it remained stable during sevoflurane anesthesia.In the second year, we investigated the effects of propofol and thiamylal on swallowing reflex in 26 adult volunteers. They were sedated with either propofol (Group P : n=16) or thiamylal (Group T : n=10). Swallowing was induced by bolus injections of distilled water (0.25, 0.5, 0.75 and 1.0 mL) into the pharynx via an epidural catheter. The responses to injections of water were analyzed in terms of the number of swallows elicited and the latency of response. The latency was prolonged and the number of swallows were decreased in Group F, but not in Group T.These results suggest that propofol depresses swallowing reflex greater than that of thiamylal.