非体外循环冠状动脉搭桥手术的麻醉方法及血液动力学和氧代谢的变化

Hemodynamic changes and oxygen metabolism during off-pump coronary artery bypass grafting

目的 观察非体外循环冠状动脉搭桥手术的麻醉方法、术中病人血液动力学和氧代谢的变化以及术后病人的早期情况。方法 非体外循环冠状动脉搭桥手术病人20例,麻醉用咪唑安定0.1～0.2 mg/kg、芬太尼15～30μg/kg及0.5％-2％的吸入麻醉药等,在切皮前、开心包后、心脏操作中、操作完成后10min及术毕观察血液动力学指标及脑氧饱和度,同时采集桡动脉和肺动脉血,测定血气及动脉血乳酸(ABL),计算氧供(DO2)、氧耗(VO2)和氧摄取率(ERO2)。术后早期观察术后拔除气管插管、ICU停留及术后住院时间、并发症及死亡等情况。结果 心脏操作中MAP、SV、CI下降,HR、CVP升高,MAP下降以搭回旋支时最明显(P<0.01),HR升高以搭右冠时最明显(P<0.01);心脏操作中DO2降低(P<0.05),VO2无变化,ERO2升高(P<0.01);操作后DO2、ERO2恢复至操作前水平;操作后ABL升高(P<0.01)。结论 本组麻醉方法使病人安全度过非体外循环搭桥术,在心脏操作期易出现血压、每搏量、心指数下降,伴心率、静脉压升高,但时间短暂无严重后果,氧代谢紊乱及缺氧程度较轻。

Objective To examine the hemodynamic changes and oxygen metabolism during off-pump coronary artery bypass grafting (OPCABG) .Methods Twenty patients (18 male, 2 female) aged (60±8)yr, weighing (71±9)kg undergoing OPCABG were studied. The patients were premedicated with diazepam 10 mg PO 2h before operation and morphine 10 mg and scopolamine 0.3 mg im 30 min before operation. Anesthesia was induced with midazolam 0.1-0.2 mg·kg-1, fentanyl 5-10 ug·kg-1 and vecuronium 0.12-0.15 mg·kg-1 and maintained with 0.5%-2% isoflurane inhalation, fentanyl 10-20 ug·kg-1 and intermittent iv boluses of vecuronium and in some patients propofol infusion. Radial artery was cannulated. Swan-Ganz catheter was placed via internal jugular vein into pulmonary artery. Hemodynamic parameters including MAP, HR, cardiac index (CI), stroke volume (SV), MPAP, PCWP, SVR, left ventricle stroke work index (LVSWI) and RVSWI; oxygen metabolism including oxygen delivery (DO2) , oxygen consumption (VO2) and oxygen extraction ratio (ERO2); regional cerebral oxygen saturation (rSCO2) and arterial blood lactate level (ABL) were measured and recorded before skin incision (A), when pericardium was incised before operation on the heart (B), during operation on the heart (C), 10 min after operation on the heart (D) and at the end of surgery (E) . Results During surgical manipulation on the heart (C) MAP, SV and CI decreased while CVP and HR increased, but the decrease in CI and SV was not significant. During manipulation on the heart(C) DO2 decreased whereas ERO2 increased, but there was no significant change in VO2. After manipulation on the heart (D) DO2 and ERO2 returned to the pre-manipulation level. Arterial blood lactate concentration increased at E. Conclusion OPCABG can be performed uneventfully under our general anesthetic regimen. During operation while the beating heart is being manipulated MAP tends to decrease while CVP and HR increase. The changes are of short duration and do not result in any serious consequeaces.