Department of Anesthesia and Intensive Care, University of Foggia, Foggia, Italy.
Anesthesiology. 2013 Jan;118(1):114-22. doi: 10.1097/ALN.0b013e3182746a10.
The authors tested the hypothesis that during laparoscopic surgery, Trendelenburg position and pneumoperitoneum may worsen chest wall elastance, concomitantly decreasing transpulmonary pressure, and that a protective ventilator strategy applied after pneumoperitoneum induction, by increasing transpulmonary pressure, would result in alveolar recruitment and improvement in respiratory mechanics and gas exchange.
In 29 consecutive patients, a recruiting maneuver followed by positive end-expiratory pressure 5 cm H(2)O maintained until the end of surgery was applied after pneumoperitoneum induction. Respiratory mechanics, gas exchange, blood pressure, and cardiac index were measured before (T(BSL)) and after pneumoperitoneum with zero positive end-expiratory pressure (T(preOLS)), after recruitment with positive end-expiratory pressure (T(postOLS)), and after peritoneum desufflation with positive end-expiratory pressure (T(end)).
Esophageal pressure was used for partitioning respiratory mechanics between lung and chest wall (data are mean ± SD): on T(preOLS), chest wall elastance (E(cw)) and elastance of the lung (E(L)) increased (8.2 ± 0.9 vs. 6.2 ± 1.2 cm H(2)O/L, respectively, on T(BSL); P = 0.00016; and 11.69 ± 1.68 vs. 9.61 ± 1.52 cm H(2)O/L on T(BSL); P = 0.0007). On T(postOLS), both chest wall elastance and E(L) decreased (5.2 ± 1.2 and 8.62 ± 1.03 cm H(2)O/L, respectively; P = 0.00015 vs. T(preOLS)), and Pao(2)/inspiratory oxygen fraction improved (491 ± 107 vs. 425 ± 97 on T(preOLS); P = 0.008) remaining stable thereafter. Recruited volume (the difference in lung volume for the same static airway pressure) was 194 ± 80 ml. Pplat(RS) remained stable while inspiratory transpulmonary pressure increased (11.65 + 1.37 cm H(2)O vs. 9.21 + 2.03 on T(preOLS); P = 0.007). All respiratory mechanics parameters remained stable after abdominal desufflation. Hemodynamic parameters remained stable throughout the study.
In patients submitted to laparoscopic surgery in Trendelenburg position, an open lung strategy applied after pneumoperitoneum induction increased transpulmonary pressure and led to alveolar recruitment and improvement of E(cw) and gas exchange.
作者测试了这样一个假设，即在腹腔镜手术中，Trendelenburg 体位和气腹可能会使胸壁弹性变差，同时降低跨肺压，而在气腹诱导后应用保护性通气策略，通过增加跨肺压，将导致肺泡复张，并改善呼吸力学和气体交换。
在 29 例连续患者中，在气腹诱导后应用了复张手法，然后施加 5cmH2O 的呼气末正压，持续到手术结束。在气腹前（T（BSL））、零呼气末正压时（T（preOLS））、复张后（T（postOLS））和腹部放气后（T（end））测量呼吸力学、气体交换、血压和心指数。
食管压用于将呼吸力学在肺和胸壁之间进行划分（数据为平均值±标准差）：在 T（preOLS）时，胸壁弹性（E（cw））和肺弹性（E（L））增加（分别为 8.2±0.9cmH2O/L 和 6.2±1.2cmH2O/L，与 T（BSL）相比，P=0.00016；和 11.69±1.68cmH2O/L 和 9.61±1.52cmH2O/L，与 T（BSL）相比，P=0.0007）。在 T（postOLS）时，E（cw）和 E（L）均降低（分别为 5.2±1.2cmH2O/L 和 8.62±1.03cmH2O/L，与 T（preOLS）相比，P=0.00015），并且 PaO2/吸入氧分数改善（491±107mmHg 与 425±97mmHg，与 T（preOLS）相比，P=0.008），此后保持稳定。募集容积（相同静态气道压力下的肺容积差异）为 194±80ml。平台压（RS）保持稳定，而吸气跨肺压增加（11.65±1.37cmH2O 与 9.21±2.03cmH2O，与 T（preOLS）相比，P=0.007）。腹部放气后所有呼吸力学参数均保持稳定。整个研究过程中血流动力学参数保持稳定。
在接受 Trendelenburg 体位腹腔镜手术的患者中，气腹诱导后应用开肺策略增加了跨肺压，导致肺泡复张，并改善了 E（cw）和气体交换。
