个体化呼气末正压设置可优化术中机械通气并减少术后肺不张。

Individual Positive End-expiratory Pressure Settings Optimize Intraoperative Mechanical Ventilation and Reduce Postoperative Atelectasis.

机构信息

From Divisao de Anestesia, Terapia Intensiva e Dor (S.M.P., C.M.S., B.F.F.T., M.S.P., J.E.V.) Divisao de Pneumologia, Instituto do Coracao (S.M.P., M.R.T., C.C.A.M., M.B.P.A.), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil Anesthesia Department, Hospital Sírio-Libanes, Sao Paulo, Brazil (C.M.S., B.F.F.T, ) UT Southwestern Medical Center - Radiology Department, Dallas, Texas (F.U.K.) Department of Surgical Sciences and Integrated Diagnostics, IRCCS San Martino Policlinico Hospital, University of Genoa, Italy (P.P.).

出版信息

Anesthesiology. 2018 Dec;129(6):1070-1081. doi: 10.1097/ALN.0000000000002435.

DOI:10.1097/ALN.0000000000002435

PMID:30260897

Abstract

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Intraoperative lung-protective ventilation has been recommended to reduce postoperative pulmonary complications after abdominal surgery. Although the protective role of a more physiologic tidal volume has been established, the added protection afforded by positive end-expiratory pressure (PEEP) remains uncertain. The authors hypothesized that a low fixed PEEP might not fit all patients and that an individually titrated PEEP during anesthesia might improve lung function during and after surgery.

METHODS

Forty patients were studied in the operating room (20 laparoscopic and 20 open-abdominal). They underwent elective abdominal surgery and were randomized to institutional PEEP (4 cm H2O) or electrical impedance tomography-guided PEEP (applied after recruitment maneuvers and targeted at minimizing lung collapse and hyperdistension, simultaneously). Patients were extubated without changing selected PEEP or fractional inspired oxygen tension while under anesthesia and submitted to chest computed tomography after extubation. Our primary goal was to individually identify the electrical impedance tomography-guided PEEP value producing the best compromise of lung collapse and hyperdistention.

RESULTS

Electrical impedance tomography-guided PEEP varied markedly across individuals (median, 12 cm H2O; range, 6 to 16 cm H2O; 95% CI, 10-14). Compared with PEEP of 4 cm H2O, patients randomized to the electrical impedance tomography-guided strategy had less postoperative atelectasis (6.2 ± 4.1 vs. 10.8 ± 7.1% of lung tissue mass; P = 0.017) and lower intraoperative driving pressures (mean values during surgery of 8.0 ± 1.7 vs. 11.6 ± 3.8 cm H2O; P < 0.001). The electrical impedance tomography-guided PEEP arm had higher intraoperative oxygenation (435 ± 62 vs. 266 ± 76 mmHg for laparoscopic group; P < 0.001), while presenting equivalent hemodynamics (mean arterial pressure during surgery of 80 ± 14 vs. 78 ± 15 mmHg; P = 0.821).

CONCLUSIONS

PEEP requirements vary widely among patients receiving protective tidal volumes during anesthesia for abdominal surgery. Individualized PEEP settings could reduce postoperative atelectasis (measured by computed tomography) while improving intraoperative oxygenation and driving pressures, causing minimum side effects.

摘要

背景

术中肺保护性通气已被推荐用于减少腹部手术后的肺部并发症。虽然已经确定了更生理的潮气量的保护作用，但呼气末正压（PEEP）的附加保护作用仍不确定。作者假设，低固定 PEEP 可能不适合所有患者，并且在麻醉期间滴定 PEEP 可能会改善手术期间和手术后的肺功能。

方法

40 名患者在手术室接受研究（腹腔镜 20 例，开腹手术 20 例）。他们接受择期腹部手术，并随机分为机构 PEEP（4 cm H2O）或电气阻抗断层摄影术引导的 PEEP（在募集手法后应用，并针对最小化肺塌陷和过度膨胀，同时）。在麻醉下拔管时，患者无需更改选定的 PEEP 或吸入氧分压，并在拔管后接受胸部计算机断层扫描。我们的主要目标是单独确定电气阻抗断层摄影术引导的 PEEP 值，以产生肺塌陷和过度膨胀的最佳折衷。

结果

电气阻抗断层摄影术引导的 PEEP 在个体之间差异很大（中位数为 12 cm H2O；范围为 6 至 16 cm H2O；95%置信区间为 10-14）。与 4 cm H2O 的 PEEP 相比，随机接受电气阻抗断层摄影术指导策略的患者术后肺不张较少（术后组织质量的 6.2 ± 4.1%与 10.8 ± 7.1%；P = 0.017），术中驱动压较低（手术期间的平均值为 8.0 ± 1.7 vs. 11.6 ± 3.8 cm H2O；P <0.001）。电气阻抗断层摄影术指导的 PEEP 臂具有更高的术中氧合作用（腹腔镜组的 435 ± 62 与 266 ± 76 mmHg；P <0.001），同时表现出等效的血液动力学（手术期间的平均动脉压为 80 ± 14 与 78 ± 15 mmHg；P = 0.821）。