硝普钠不同程度降压对颅脑手术患者肝肾功能的影响

Effects of sodium nitroprusside-induced controlled hypotension to different degree on liver and renal function in patients undergoing neurosurgical operation

目的采用新的肝肾功能敏感指标，评估颅脑手术患者硝普钠不同程度控制性降压的安全性。方法择期行颅脑手术的患者45例。随机数字表法分为3组，每组15例。A组、B组于去骨瓣后微量泵输注硝普钠行控制性降压，降至目标血压后维持60min，A组平均动脉压（MAP）控制在50～55mmHg，B组MAP控制在60～65mmHg，C组（对照组）不行控制性降压。分别于开始降压时（T0）、降至目标压后60min（T1）、停止降压后60min（T2）、停止降压后24h（T3）采集动脉血，测定血清α-谷胱甘肽-S-转移酶（α-GST）、血清胱抑素C浓度。结果在T1时A组、B组、C组之间MAP比较从低到高依次为A组〈B组〈C组（均P〈0．05）。A组和B组的MAP在T1时显著低于T0（均P〈0．01）。A组的血清α-GST浓度在T，和T2时显著高于T0（均P〈0．01），并显著高于B组和C组（均P〈0．01）。A组的血清胱抑素C浓度在T，时显著高于T0（P〈001），并显著高于B组和C组（均P〈0．05）。结论硝普钠行控制性降压至50～55mmHg可以引起可逆性肝细胞损害及肾小球滤过功能下降，控制性降压程度以60～65mmHg为宜。

Objective To investigate the influence of controlled hypotension （CH） induced by sodium nitroprusside to different degree on liver and renal function in patients undergoing neurosurgical operation. Methods 45 patients scheduled for elective neurosurgical operation were randomly divided into three groups （n=15 per group）： In group A, mean arterial pressure （MAP） was kept between 50-55 mmHg, In group B, MAP was kept between 60-65 mmHg, in groupC （Control group）, no hypotension was performed. All patients were intubated and mechanically ventilated after induction of general anesthesia. In group A and B CH were conducted after removal of bone flap by continuous infusion of sodium nitroprusside at 0.5-5μg·kg^-1·min^-1, MAP was reduced to target pressure in 20 min and maintained for 60 min. Blood samples were taken and urine was collected before induced hypotension （T0）,at 60 min during hypotension （T1） and 60 rain after hypotension （T2） and 24h after hypotension （T3） for determination of serum levels of alpha-glutathione-S-transferase （alpha-GST） and standard liver enzymes （alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase） and serum cystatin C （SCysC） and urinary al-microglobulin （α-MG）, N-acetyl-beta-D-glucosaminidase （NAG）. Results The group order of MAP at T1 was group A 〈 group B 〈 group C （ P〈0.01 or 0.05）. MAP in group A and B were significantly decreased at T1 as compared with To （P〈 0.01）. In group A alpha-GST concentrations at T1 and T2 were significantly increased as compared with To （P 〈 0.01） and significantly higher than those in group B and C （P〈0.01）. In group A SCysC concentrations at T1 were significantly increased as compared with To （P〈0.01）and significantly higher than those in group B and C （P〈0.05）. Conclusion Controlled hypotension induced by sodium nitroprusside （MAP kept between 50-55 mm Hg） induced a transient damage of hepatocellular integrity,also decreased glomerular filtration rate, suggesting that the margin of safety for controlled hypotension, a lower limit of 60 mmHg for MAP might be more adequate for liver perfusion and kidney microcirculationo