Department of Anesthesiology, Eye & Ear, Nose, and Throat Hospital of Fudan University, Shanghai, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Department of Anesthesiology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Department of Anesthesiology, Huzhou Central Hospital, Huzhou, China.
Anesthesiology. 2023 Sep 1;139(3):262-273. doi: 10.1097/ALN.0000000000004603.
Individualized positive end-expiratory pressure (PEEP) guided by dynamic compliance improves oxygenation and reduces postoperative atelectasis in nonobese patients. The authors hypothesized that dynamic compliance-guided PEEP could also reduce postoperative atelectasis in patients undergoing bariatric surgery.
Patients scheduled to undergo laparoscopic bariatric surgery were eligible. Dynamic compliance-guided PEEP titration was conducted in all patients using a downward approach. A recruitment maneuver (PEEP from 10 to 25 cm H2O at 5-cm H2O step every 30 s, with 15-cm H2O driving pressure) was conducted both before and after the titration. Patients were then randomized (1:1) to undergo surgery under dynamic compliance-guided PEEP (PEEP with highest dynamic compliance plus 2 cm H2O) or PEEP of 8 cm H2O. The primary outcome was postoperative atelectasis, as assessed with computed tomography at 60 to 90 min after extubation, and expressed as percentage to total lung tissue volume. Secondary outcomes included Pao2/inspiratory oxygen fraction (Fio2) and postoperative pulmonary complications.
Forty patients (mean ± SD; 28 ± 7 yr of age; 25 females; average body mass index, 41.0 ± 4.7 kg/m2) were enrolled. Median PEEP with highest dynamic compliance during titration was 15 cm H2O (interquartile range, 13 to 17; range, 8 to 19) in the entire sample of 40 patients. The primary outcome of postoperative atelectasis (available in 19 patients in each group) was 13.1 ± 5.3% and 9.5 ± 4.3% in the PEEP of 8 cm H2O and dynamic compliance-guided PEEP groups, respectively (intergroup difference, 3.7%; 95% CI, 0.5 to 6.8%; P = 0.025). Pao2/Fio2 at 1 h after pneumoperitoneum was higher in the dynamic compliance-guided PEEP group (397 vs. 337 mmHg; group difference, 60; 95% CI, 9 to 111; P = 0.017) but did not differ between the two groups 30 min after extubation (359 vs. 375 mmHg; group difference, -17; 95% CI, -53 to 21; P = 0.183). The incidence of postoperative pulmonary complications was 4 of 20 in both groups.
Postoperative atelectasis was lower in patients undergoing laparoscopic bariatric surgery under dynamic compliance-guided PEEP versus PEEP of 8 cm H2O. Postoperative Pao2/Fio2 did not differ between the two groups.
在非肥胖患者中，通过动态顺应性指导的个体化呼气末正压（PEEP）可改善氧合并减少术后肺不张。作者假设动态顺应性指导的 PEEP 也可以减少减重手术患者的术后肺不张。
入选拟行腹腔镜减重手术的患者。所有患者均采用下行法进行动态顺应性指导的 PEEP 滴定。在滴定前后均进行了募集操作（PEEP 从 10 至 25 cm H2O，每 30 秒增加 5 cm H2O，驱动压力为 15 cm H2O）。然后，患者随机（1:1）接受动态顺应性指导的 PEEP（最高动态顺应性加 2 cm H2O）或 8 cm H2O 的 PEEP 手术。主要结局是术后肺不张，在拔管后 60 至 90 分钟使用计算机断层扫描评估，并表示为与总肺组织体积的百分比。次要结局包括 PaO2/吸入氧分数（Fio2）和术后肺部并发症。
共纳入 40 例患者（平均年龄±标准差；28±7 岁；女性 25 例；平均体重指数为 41.0±4.7 kg/m2）。在整个 40 例患者样本中，在滴定过程中最高的动态顺应性的中位 PEEP 为 15 cm H2O（四分位距，13 至 17；范围，8 至 19）。术后肺不张的主要结局（每组 19 例患者可获得）分别为 8 cm H2O 组的 13.1±5.3%和动态顺应性指导 PEEP 组的 9.5±4.3%（组间差异，3.7%；95%置信区间，0.5 至 6.8%；P=0.025）。气腹后 1 小时，动态顺应性指导 PEEP 组 PaO2/Fio2 更高（397 与 337 mmHg；组间差异，60；95%置信区间，9 至 111；P=0.017），但拔管后 30 分钟两组之间没有差异（359 与 375 mmHg；组间差异，-17；95%置信区间，-53 至 21；P=0.183）。两组术后肺部并发症发生率均为 20 例中的 4 例。
与接受 8 cm H2O PEEP 的患者相比，腹腔镜减重手术患者接受动态顺应性指导的 PEEP 后术后肺不张发生率更低。两组术后 PaO2/Fio2 无差异。
