Lenkutis Tadas, Benetis Rimantas, Sirvinskas Edmundas, Raliene Laima, Judickaite Loreta
Clinic of Cardiothoracic and Vascular Surgery, Kaunas University Hospital, Kaunas, LT-50009, Lithuania.
Perfusion. 2009 Jul;24(4):243-8. doi: 10.1177/0267659109348724. Epub 2009 Oct 6.
The most important side effect of epidural anesthesia is hypotension with functional hypovolemia. Aggressive infusion therapy can reduce the hypotension effect. However, in conjunction with cardiopulmonary bypass, it can increase acute lung injury. We hypothesized that epidural anesthesia, by reducing cardiac sympathetic tonus, with subsequent better pulmonary flow, does not increase lung interstitial fluids.
Sixty patients undergoing coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) were randomized to combined general anesthesia with epidural anesthesia / analgesia, (EA) group, and to general anesthesia with i/v opiate analgesia, (GA) group. Patients in the EA group received a high thoracic epidural, preoperatively. Intraoperatively, 0.25% bupivacaine 8 mL/h was infused and general anesthesia with sevoflurane was followed by bupivacaine infusion for 48 hours postoperatively. General anesthesia in the GA group was with sevoflurane and fentanyl 10 - 12 microg/kg and analgesia with pethidinum 0.1 - 0.4 mg/kg i.v. postoperatively. Global end-diastolic volume index (GEDI), intrathoracic blood volume index (ITBI) and extravascular lung water index (ELWI) were measured before anesthesia, before CPB and 15, 60, 180, 600 min. and 24 hr after CPB. Duration of mechanical lung ventilation was registered in both groups.
ITBI and GEDI were significantly higher in the EA group at all time points of measurement (ITBI 945.6+/-146.4 ml/m(2) and 870.6+/-146.5 ml/m( 2) vs. 1118+/-153.2 ml/m(2) and 1020+/-174.9 ml/m( 2); GEDI 720+/-96.19 ml/m(2) and 775.0+/-159.5 ml/m( 2) vs. 805.4+/-97.59 ml/m(2) and 888+/-117.3 ml/m( 2)). GEDI was significantly lower in the GA group compared with baseline (801.9+/-132.4 ml/m(2) vs. 695+/-169.2 mL/m(2)). ELWI was significantly higher in the GA group (7.233+/-1.35 ml/kg and 7.333+/-1.32 ml/kg vs. 8.533+/-1.45 ml/kg and 8.633+/-1.71 ml/kg), but without significant changes in the EA group. Duration of mechanical lung ventilation was shorter in the EA group (663.7+/-98.39 min. vs. 362.2+/-33.72 min.).
Epidural anesthesia / analgesia does not increase interstitial lung fluids by increasing intrathoracic blood volume or the amount of infusion fluids in patients undergoing cardiac surgery under cardiopulmonary bypass. There is, also, a decreased duration of mechanical lung ventilation.
硬膜外麻醉最重要的副作用是伴有功能性血容量不足的低血压。积极的输液治疗可减轻低血压效应。然而，在体外循环期间，它可能会增加急性肺损伤。我们推测，硬膜外麻醉通过降低心脏交感神经张力，继而改善肺血流，不会增加肺间质液。
60例行体外循环冠状动脉搭桥术（CABG）的患者被随机分为全身麻醉联合硬膜外麻醉/镇痛（EA）组和全身麻醉联合静脉注射阿片类镇痛（GA）组。EA组患者术前接受高位胸段硬膜外麻醉。术中，输注0.25%布比卡因8 mL/h，术后用七氟醚进行全身麻醉，随后输注布比卡因48小时。GA组全身麻醉采用七氟醚和10 - 12μg/kg芬太尼，术后静脉注射0.1 - 0.4mg/kg哌替啶镇痛。在麻醉前、体外循环前以及体外循环后15、60、180、6百分钟和24小时测量全心舒张末期容积指数（GEDI）、胸腔内血容量指数（ITBI）和血管外肺水指数（ELWI）。记录两组机械通气时间。
在所有测量时间点，EA组的ITBI和GEDI均显著更高（ITBI分别为945.6±146.4ml/m²和870.6±146.5ml/m²，对比1118±153.2ml/m²和1020±174.9ml/m²；GEDI分别为720±96.19ml/m²和775.0±159.5ml/m²，对比805.4±97.59ml/m²和888±117.3ml/m²）。GA组的GEDI与基线相比显著降低（801.9±132.4ml/m²对比695±169.2mL/m²）。GA组的ELWI显著更高（分别为7.233±1.35ml/kg和7.333±1.32ml/kg，对比8.533±1.45ml/kg和8.633±1.71ml/kg），但EA组无显著变化。EA组的机械通气时间更短（663.7±98.39分钟对比362.2±33.72分钟）。
在体外循环心脏手术患者中，硬膜外麻醉/镇痛不会通过增加胸腔内血容量或输液量来增加肺间质液。此外，机械通气时间也会缩短。
