体位和正压通气对病态肥胖患者功能残气量的影响：一项随机试验。

Effect of position and positive pressure ventilation on functional residual capacity in morbidly obese patients: a randomized trial.

机构信息

Department of Anesthesiology and Critical Care, Laval University, Québec, Canada.

Department of Pneumology, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, QC, Canada.

出版信息

Can J Anaesth. 2018 May;65(5):522-528. doi: 10.1007/s12630-018-1050-1. Epub 2018 Jan 18.

DOI:10.1007/s12630-018-1050-1

PMID:29435810

Abstract

PURPOSE

In morbidly obese patients, the position and ventilation strategy used during pre-oxygenation influence the safe non-hypoxic apnea time and the functional residual capacity (FRC). In awake morbidly obese volunteers, we hypothesized that the FRC would be higher after a five-minute period of positive pressure ventilation compared with spontaneous ventilation at zero inspiratory pressure.

METHODS

Using a prospective crossover randomized trial design, obese subjects underwent, in a randomized order, a combination of one of three positions, supine (S), beach chair (BC), and reverse Trendelenburg (RT), and one of two ventilation strategies, spontaneous ventilation at zero inspiratory pressure (ZEEP-SV) or with positive pressure (PP-SV) set to an inspiratory pressure of 8 cmHO, positive end-expiratory pressure of 10 cmHO, and fraction of inspired oxygen of 0.21.

RESULTS

Seventeen obese volunteers with a mean (standard deviation; SD) body mass index of 50 (8) kg·m were included. Mean (SD) FRC in the three positions (S, BC, RT) was significantly higher using PP-SV compared with ZEEP-SV [2571 (477) vs 2215 (481) mL, respectively; mean difference, 356; 95% confidence interval (CI), 209 to 502; P < 0.001]. Mean (SD) FRC was significantly higher in the RT compared with BC position [2483 (521) vs 2338 (469) mL, respectively; mean difference, 145; 95% CI, 31 to 404; P = 0.01], while there was no difference between S and BC [2359 (519) mL vs 2338 (469) mL, respectively; mean difference, 21; 95% CI, -93 to 135; P = 0.89].

CONCLUSION

In awake morbidly obese volunteers, an increase in the FRC is observed when spontaneous ventilation at zero inspiratory pressure is switched to positive pressure. Compared with S positioning, the BC position had no measurable impact on the FRC. The RT position resulted in an optimal FRC.

TRIAL REGISTRATION

clinicaltrials.gov (NCT02121808). Registered 24 April 2014.

摘要

目的

在病态肥胖患者中，预充氧期间使用的体位和通气策略会影响安全无低氧性暂停时间和功能残气量（FRC）。在清醒的病态肥胖志愿者中，我们假设与零吸气压力下的自主通气相比，正压通气 5 分钟后 FRC 会更高。

方法

采用前瞻性交叉随机试验设计，肥胖受试者以随机顺序接受三种体位（仰卧位[S]、沙滩椅位[BC]和反向特伦德伦伯卧位[RT]）和两种通气策略（零吸气压力自主通气[ZEEP-SV]或正压通气[PP-SV]，吸气压力设为 8 cmH2O，呼气末正压为 10 cmH2O，吸入氧分数为 0.21）的组合。

结果

纳入 17 名肥胖志愿者，平均（标准差；SD）体重指数为 50（8）kg·m。与 ZEEP-SV 相比，三种体位（S、BC、RT）下的 FRC （PP-SV）明显更高[分别为 2571（477）和 2215（481）mL；平均差值，356；95%置信区间（CI），209 至 502；P<0.001]。与 BC 位相比，RT 位的 FRC 明显更高[分别为 2483（521）和 2338（469）mL；平均差值，145；95%CI，31 至 404；P=0.01]，而 S 位与 BC 位之间无差异[分别为 2359（519）和 2338（469）mL；平均差值，21；95%CI，-93 至 135；P=0.89]。