可乐定用于原发性高血压病人术后自控硬膜外镇痛的效应

Clonidine for postoperative patient-controNed epidural analgesia (PCEA) in patients with essential hypertension

目的 观察可乐定用于原发性高血压病人术后自控硬膜外镇痛(PCEA)的效果、对血液动力学和血浆内皮素-1(ET-1)、降钙素基因相关肽(CGRP)浓度的影响。方法60例ASA Ⅰ-Ⅱ级择期行盆腔手术的原发性高血压病人,均采用全麻复合硬膜外阻滞。术后随机分为三组(n=20),均行PCEA。镇痛药液:A组吗啡2 mg和罗哌卡因75 mg;B组可乐定150μg、吗啡2 mg和罗哌卡因75 mg;C组可乐定300μg、吗啡2 mg和罗哌卡因75 mg。监测术前、后血压(BP)、心率(HR)及进行VAS评分、Remesay镇静评分,记录24h总按压次数、实进次数、镇痛药总用量,并测定麻醉诱导前、术后6、24 h血浆ET-1和CGRP浓度。结果 术后24 h VAS评分:A组高于B组(P<0.01),B组高于C组(P<0.05)。B、C组24 h总按压次数、实进次数、镇痛药总用量显著性低于A组(P<0.01),且C组低于B组(P<0.01)。A、B、C组镇静评分分别为2.5±0.4、2.9±0.7、(3.9±0.7)分,A组低于B组,B组低于C组(P<0.05或0.01)。与术前相比,A、B两组术后BP、HR、血浆ET-1和CGRP浓度差异无统计学意义(P>0.05),而C组术后BP、HR和血浆ET-l浓度均显著性降低,CGRP浓度显著性升高(P<0.01)。结论 可乐定用于原发性高血压病人术后PCEA不仅能发挥良好镇痛作用,而且降低动脉BP,使血浆缩血管/舒血管神经肽比例平衡,可防止术?

Objective To evaluate the effect of clonidine as an adjuvant of PCEA with morphine and ropivacaine in patients with essential hypertension and it' s effects on hemodynamics and plasma concentrations of endothelin-1 ( ET-1) and calcium gene-related peptide ( CGRP) . Methods Sixty ASAⅠ - Ⅱ patients of both sexes (24 males, 36 females) with a history of essential hypertension for 1-2 years were included in this study. The patients ranged in age from 45-72 yrs and in body weight 55-70 kg and were scheduled for elective pelvic surgery under combined general-epidural anesthesia. An epidural catheter was placed at T12-L1 or L1-2 interspace before induction of general anesthesia. Anesthesia was induced with fentanyl 4 μg · kg-1 , propofol 2 mg·kg-1 and vecuronium 0.1 mg·kg-1 and maintained with isoflurane and epidural analgesia. The patients received PCEA after operation. The PCEA regimen included a loading dose of 5 ml followed by background infusion at 2 ml·h-1 with an 1 ml bolus dose and a 15 min lockout interval. The PCEA solution contained morphine 2 mg + ropivacaine 75 mg in group A (n = 20); clonidine 150 μg + morphine 2 mg + ropivacaine 75 mg in group B ( n = 20) ; clonidine 300 μg + morphine 2 mg + ropivacaine 75 mg in group C ( n = 20) in 60 ml of normal saline. BP, HR, VAS pain score (0 = no pain, 10 worst pain) and Ramsay sedation score (1 = wide awake, 5-6 over sedated) were recorded one day before operation (T0), before induction of anesthesia (T1 ), 0, 5, 15, 30, 60 min, 2, 4, 8, 20, 24 h (T2-11 ) after PCEA was commenced. Blood samples were taken before induction of anesthesia (baseline) and 6 and 24 h after operation for determination of plasma concentrations of ET-1 and CGRP. The total number of button pressing (D1) and the number of actual delivery of bolus dose (D2) and the consumption of PCEA solution were also recorded. Results VAS pain score was significantly higher in group A than that in group B and C ( P <0.01) Ramsay sedation score in group C was the highest among the 3 groups. The consumption of PCEA solution and D1 D2 were significantly higher in group A than in group B and C (P<0.01).BP and HR were significandy decreased after operation in group C compared with the baseline value before anesthesia (P<0.01), whereas in group A and B there was no significant difference in BP and HR before and after operation. In group C the plasma ET-1 level was significandy lower while plasma CGRP level was significandy higher after operation compared with those before operation ( P<0.01). But there was no significant difference in plasma ET-1 and CGRP levels before and after operation in group A and B.Conclusion Clonidine as an adjuvant of PCEA with morphine and ropivacaine can not only provide better analgesia but also significandy decrease BP, suppress plasma ET-1 level and increase plasma CGRP concentration thus effectively preventing hypertension from deteriorating.