Schrijvers D, Mottrie A, Traen K, De Wolf A M, Vandermeersch E, Kalmar A F, Hendrickx J F A
Department of Anesthesiology, OLV Hospital, Aalst, Belgium.
Acta Anaesthesiol Belg. 2009;60(4):229-33.
During robot assisted hysterectomies and prostatectomies, surgical exposure demands the application of a CO2 pneumoperitoneum with a very steep Trendelenburg position (40 degrees). The extent to which oxygenation and ventilation might be compromised intra-operatively remains poorly documented.
Dead-space ventilation and venous admixture were determined in 18 patients undergoing robot assisted hysterectomy (n = 6) or prostatectomy (n = 12). Anesthesia was maintained with desflurane in O2 or O2/air, with the inspired O2 fraction left at the discretion of the attending anesthesiologist. Controlled mechanical ventilation was used, but 15 min after assuming the Trendelenburg position and up until resuming the supine position pressure controlled ventilation was used. Dead-space ventilation and venous admixture were determined using Bohr's formula and Nunn's iso-shunt diagram, respectively, at the following 7 stages of the procedure: 15 min after induction; 5 min after applying the CO2 pneumoperitoneum (intra-abdominal pressure 12 mm Hg) but while still supine; 5, 60, and 120 min after assuming the Trendelenburg positioning; and 5 and 15 min after reassuming the supine position.
Venous admixture did not change. Dead-space ventilation increased after Trendelenburg positioning, and returned to baseline values after resuming the supine position. However, individual patterns varied widely.
The lung has a remarkable yet incompletely understood capacity to withstand the effects of a CO2 pneumoperitoneum and steep Trendelenburg position during general anesthesia. While individual responses vary and should be monitored, effects on dead-space ventilation and venous admixture are small and should not be an obstacle to provide optimal surgical exposure during robot assisted prostatectomy or hysterectomy.
在机器人辅助子宫切除术和前列腺切除术中，手术暴露需要应用二氧化碳气腹并采用非常陡峭的头低脚高位（40度）。术中氧合和通气可能受到影响的程度仍缺乏充分记录。
对18例行机器人辅助子宫切除术（n = 6）或前列腺切除术（n = 12）的患者测定死腔通气和静脉血掺杂情况。采用地氟醚在氧气或氧气/空气混合气体中维持麻醉，吸入氧分数由主治麻醉医师酌情决定。使用控制机械通气，但在采用头低脚高位15分钟后直至恢复仰卧位期间采用压力控制通气。在手术的以下7个阶段分别使用玻尔公式和纳恩等分流图测定死腔通气和静脉血掺杂情况：诱导后15分钟；应用二氧化碳气腹（腹腔内压力12毫米汞柱）但仍为仰卧位时5分钟；采用头低脚高位后5、60和120分钟；以及恢复仰卧位后5和15分钟。
静脉血掺杂未发生变化。头低脚高位后死腔通气增加，恢复仰卧位后恢复至基线值。然而，个体模式差异很大。
在全身麻醉期间，肺具有显著但尚未完全了解的能力来承受二氧化碳气腹和陡峭头低脚高位的影响。虽然个体反应各不相同，应予以监测，但对死腔通气和静脉血掺杂的影响较小，不应成为在机器人辅助前列腺切除术或子宫切除术中提供最佳手术暴露的障碍。
