全麻复合硬膜外麻醉用于胸科手术对细胞因子及内脏缺血的影响

Effect of thoracic epidural anesthesia combined with general anesthesia on cytokine production and gut mucosal perfusion

目的 了解胸部手术时细胞因子、粘膜内pH(pHi)、组织动脉CO2分压差P(t-a)CO2的变化及相关关系,并观察全麻复合硬膜外阻滞(GEA)对细胞因子和粘膜缺血的影响。方法 20例肺叶或肺叶局部切除手术病人随机分为两组,GEA组和单纯全麻(GA)组,于术前、切皮时、切皮后2h、4h、6h、术后第一、三日晨取血测定白介素-6(IL-6)、白介素-10(IL-10)水平及术前、切皮时、切皮后1h、2h、4h、6h的pHi、P(t-a)CO2值。结果 (1)两组IL-6、IL-10手术开始后升高,组间无统计学差异。(2)pHi呈降低趋势,组间无显著差异;P(t-a)CO2,呈渐升高趋势,与pHi负相关(r=-0.318),P(t-a)-CO2在切皮后4h GEA组低于GA组(P<0.01)。(3)pHi与IL-6呈显著负相关(r=-0.252)。结论 (1)胸部手术引起细胞因子改变,并且不受硬膜外阻滞影响。(2)胸科手术导致胃肠道粘膜缺血,P(t-a)CO2可反映内脏组织灌流,胸段硬膜外阻滞可改善内脏组织灌流。(3)胃肠道粘膜缺血与细胞因子可能有相互影响。

Objective To investigate the changes in plasma concentrations of IL-6 and IL-10, pHi and the difference between tissue and arterial PCO2 [(P(t-a)CO2 ] during pulmonary surgery and the effects of thoracic epidural anesthesia on cytokine production and gut mucosal perfusion. Methods Twenty ASA class Ⅰ - Ⅱ patients undergoing elective pulmonary surgery, were randomly assigned to be operated upon under general anesthesia (group GA , n = 10) or under general anesthesia combined with thoracic epidural anesthesia (group GEA, n - 10) . Premedication in both groups consisted of pethidine 50mg and scopolamine 0.3 mg im 30 min prior to surgery and oral ranitidine 150 mg the night and 1 h before operation. Anesthesia was induced with fentanyl 2 ug·kg-1 , droperidol 1 mg, propofol 1.5-2.5 mg·kg-1 and succinylcholine 1-2 mg·kg-1 and maintained with inhalation of 1%-2.5% isoflurane and 50% N2O in oxygen and intermittent iv boluses of fentanyl and vecuronium. In GEA group epidural catheter was inserted through the needl placed at T7-8 or T8-9 and advanced cephalad for 2.5-3.0 cm. A loading dose of morphine 2 mg was given followed by epidural infusion of 0.4% ropivacaine at a rate of 6 ml·h-1 during maintenance of anesthesia and the concentration of isoflurance inhaled was reduced to 0.6%-1. 5% . Postoperative analgesia was provided by epidural infusion of 0.25% ropivacaine at 6-8 ml/2h until the morning of the 3rd postoperative day. Blood samples were taken before induction, at incision and 2 h, 4 h and 6 h after the incision and on the 1st and the morning of the 3rd postoperative day for determination of IL-6 ( by radioimmunoassay) and IL-10 (ELISA) . P(t-a)CO2 and pHi were assessed by tonometry before induction, at incision and 1 h, 2 h, 4 h and 6 h after the incision. Results (1) IL-6 and IL-10 increased significantly during operation as compared with the baseline value before induction in both groups and there was no significant difference between the two groups. (2) pHi decreased significantly during operation in both groups and there was no significant difference between the two groups. pHi was negatively correlated with IL-6. (3) P(t-a)CO2 increased significantly during operation in both groups and was negatively correlated with pHi. P(t-a)CO2 was significantly higher in GA group than that in GEA group at 4h after skin incision. Conclusion Pulmonary surgery elicits both pro- and and-inflammatory cytokine response which is not affected by thoracic epidural analgesia. Thoracic surgery leads to gut mucosal hypoperfusion of which P(t-a)CO2 is an indicator. Thoracic epidural anesthesia can improve gut mucosal perfusion. There may be some correlation between cytokine production and gut mucosal hypoperfusion.