Rein K A, Stenseth R, Myhre H O, Levang O W, Krogstad A
Department of Surgery, Trondheim Regional Hospital, Norway.
Acta Anaesthesiol Scand. 1989 Jan;33(1):79-83. doi: 10.1111/j.1399-6576.1989.tb02865.x.
Clinical observation and calculation of fluid balance have shown that patients undergoing aortocoronary bypass surgery with thoracic epidural analgesia (TEA) in addition to general anesthesia retain less fluid than patients having general anesthesia only. The present study was designed to investigate whether this effect could be explained by thoracic epidural analgesia influencing the transcapillary fluid balance, i.e. the transcapillary forces (COPpl, COPif, Pif). Interstitial fluid colloid osmotic pressure (COPif) and interstitial fluid pressure (Pif) were measured subcutaneously at heart level by the blister suction technique and the wick-in-needle technique, respectively. Simultaneously plasma colloid osmotic pressure (COPpl) was recorded. Sixteen male patients were allocated to two groups, one having general anesthesia only (controls, n = 8). The other group (TEA, n = 8) received, at the induction of anesthesia, bupivacaine 50 mg via an epidural catheter as an adjunct to general anesthesia. TEA was maintained by continuous infusion for 24 h postoperatively. Preoperatively no intergroup differences were observed in "the Starling forces" (COPpl, COPif, Pif). At the start of extracorporeal circulation COPpl was significantly lower in the TEA-group than in controls. During extracorporeal circulation the transcapillary COP-gradient (COPpl-COPif) was reversed in both groups. At the end of extracorporeal circulation Pif increased to a minor degree in the TEA-group and remained significantly lower than in controls from 3 to 24 h postoperatively. The subcutaneous interstitial tissue could be less expanded postoperatively in the TEA-group, also reflected by a lower increase in Pif.
临床观察和液体平衡计算表明，在全身麻醉基础上接受胸段硬膜外镇痛（TEA）的主动脉冠状动脉搭桥手术患者，其液体潴留量少于仅接受全身麻醉的患者。本研究旨在调查这种效应是否可以通过胸段硬膜外镇痛影响毛细血管间液体平衡来解释，即毛细血管间作用力（血浆胶体渗透压[COPpl]、组织间液胶体渗透压[COPif]、组织间液压力[Pif]）。分别采用水疱抽吸技术和棉芯-针技术在心脏水平皮下测量组织间液胶体渗透压（COPif）和组织间液压力（Pif）。同时记录血浆胶体渗透压（COPpl）。16例男性患者分为两组，一组仅接受全身麻醉（对照组，n = 8）。另一组（TEA组，n = 8）在麻醉诱导时，通过硬膜外导管给予布比卡因50 mg作为全身麻醉的辅助用药。术后通过持续输注维持TEA 24小时。术前两组在“Starling力”（COPpl、COPif、Pif）方面未观察到组间差异。在体外循环开始时，TEA组的COPpl显著低于对照组。在体外循环期间，两组的毛细血管间COP梯度（COPpl - COPif）均发生逆转。在体外循环结束时，TEA组的Pif轻度升高，且在术后3至24小时仍显著低于对照组。TEA组术后皮下组织间组织扩张程度可能较小，这也体现在Pif的升高幅度较低。
