冠状动脉搭桥术患者围术期褪黑激素的分泌节律

目的研究冠状动脉搭桥术患者围术期褪黑激素和考的松的分泌节律。方法选择11名择期在低温体外循环下行冠状动脉搭桥术的男性患者进行研究。麻醉诱导和维持采用异丙酚(3mg·kg-1·h-1)持续静脉泵注,辅以芬太尼(15μg/kg)静脉注射。在术中特定时间点、术后即刻阶段以及术后第2、3天每3h抽血1次,分别用放射免疫和酶联免疫方法测定血浆褪黑激素和考的松浓度。结果术中血浆褪黑激素低于最低测定水平,但在术后即刻阶段,血浆褪黑激素呈低水平但没有节律性变化。在术后第2～3天,10名患者血浆褪黑激素呈节律性分泌,并与外界光线强度呈负相关(r=-0.480,P=0.01)。在术后即刻阶段,血浆考的松水平显著高于麻醉诱导前水平(P<0.01)。在术后第2～3天,只有3名患者恢复了考的松的昼夜节律性分泌。结论在冠状动脉搭桥术中及术后即刻阶段,褪黑激素和考的松的分泌紊乱。

Perioperative melatonin secretion rhyme in patients undergoing coronary artery bypass grafting surgery

OBJECTIVE: To investigate perioperative patterns of melatonin and cortisol secretion rhyme in patients undergoing coronary artery bypass grafting surgery. METHODS: Eleven male patients scheduled for elective coronary artery bypass grafting surgery (CABG) under hypothermic cardiopulmonary bypass (CPB) were enrolled in the study. Anesthesia was induced and maintained with propofol (3 mg.kg-1.h-1) and supplemented with fentanyl (15 micrograms/kg). Blood samples were taken during surgery at specific time-points and every 3 h in the immediate postoperative period and postoperative day 2 and day 3. Plasma melatonin and cortisol levels were measured by radioimmunoassay and enzyme-linked immunosorbent assay respectively. RESULTS: During surgery, plasma melatonin levels were below the minimum sensitivity level but low levels, without circadian variation, were measured during the immediate postoperative period. During postoperative day 2 and day 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity exposed (r = -0.480, P = 0.01). Plasma cortisol levels in the immediate postoperative period were significantly higher than those before induction of anesthesia (P < 0.01). During postoperative day 2 and day 3, only 3 patients regained circadian secretion of cortisol. CONCLUSIONS: It is concluded that melatonin and cortisol secretion are disrupted during cardiac surgery and in the immediate postoperative period.