Wirth Steffen, Biesemann Andreas, Spaeth Johannes, Schumann Stefan
Department of Anesthesiology and Critical Care, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Surg Endosc. 2017 Feb;31(2):753-760. doi: 10.1007/s00464-016-5029-0. Epub 2016 Jun 20.
Pneumoperitoneum during laparoscopic surgery leads to atelectasis and impairment of oxygenation. Positive end-expiratory pressure (PEEP) is supposed to counteract atelectasis. We hypothesized that the derecruiting effects of pneumoperitoneum would deteriorate the intratidal compliance profile in patients undergoing laparoscopic surgery.
In 30 adult patients scheduled for surgery with pneumoperitoneum, respiratory variables were measured during mechanical ventilation. We calculated the dynamic compliance of the respiratory system (C ) and the intratidal volume-dependent C curve using the gliding-SLICE method. The C curve was then classified in terms of indicating intratidal recruitment/derecruitment (increasing profile) and overdistension (decreasing profile). During the surgical interventions, the PEEP level was maintained nearly constant at 7 cm HO. Data are expressed as mean [confidence interval].
Baseline C was 60 [54-67] mL cm HO. Application of pneumoperitoneum decreased C to 40 [37-43] mL cm HO which partially recovered to 54 [50-59] mL cm HO (P < 0.001) after removal but remained below the value measured before pneumoperitoneum (P < 0.001). Baseline compliance profiles indicated intratidal recruitment/derecruitment in 48 % patients. After induction of pneumoperitoneum, intratidal recruitment/derecruitment was indicated in 93 % patients (P < 0.01), and after removal intratidal recruitment/derecruitment was indicated in 59 % patients. Compliance profiles showing overdistension were not observed.
Analyses of the intratidal compliance profiles reveal that pneumoperitoneum during laparoscopic surgery causes intratidal recruitment/derecruitment which partly persists after its removal. The analysis of the intratidal volume-dependent C profiles could be used to guide intraoperative PEEP adjustments during elevated intraabdominal pressure.
腹腔镜手术期间的气腹会导致肺不张和氧合功能受损。呼气末正压（PEEP）被认为可以抵消肺不张。我们假设气腹的去复张作用会使接受腹腔镜手术患者的潮气量顺应性曲线恶化。
在30例计划进行气腹手术的成年患者中，在机械通气期间测量呼吸变量。我们使用滑动切片法计算呼吸系统的动态顺应性（C）和潮气量依赖性C曲线。然后根据潮气量复张/去复张（曲线上升）和过度扩张（曲线下降）对C曲线进行分类。在手术干预期间，PEEP水平几乎恒定维持在7 cmH₂O。数据表示为平均值[置信区间]。
基线C为60[54 - 67]mL/cmH₂O。气腹应用使C降至40[37 - 43]mL/cmH₂O，移除后部分恢复至54[50 - 59]mL/cmH₂O（P < 0.001），但仍低于气腹前测量值（P < 0.001）。基线顺应性曲线表明48%的患者存在潮气量复张/去复张。气腹诱导后，93%的患者出现潮气量复张/去复张（P < 0.01），移除后59%的患者出现潮气量复张/去复张。未观察到显示过度扩张的顺应性曲线。
对潮气量顺应性曲线的分析表明，腹腔镜手术期间的气腹会导致潮气量复张/去复张，在气腹移除后部分持续存在。对潮气量依赖性C曲线的分析可用于指导腹内压升高期间的术中PEEP调整。
