肥胖患者术中通气策略与术后肺部并发症的关系
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Intraoperative ventilation settings and their associations with postoperative pulmonary complications in obese patients
背景与目的
术中机械通气的患者采用保护性肺通气策略得到了广泛的共识。有研究指出，术中使用小潮气量，中等水平呼气末正压（PEEP）通气以及术中肺复张可改善预后，但保护性肺通气策略对肥胖患者是否同样有效，以及各呼吸参数与术后肺部并发症间的相关性仍未确定。因此，本研究旨在探讨目前肥胖患者术中机械通气的策略和参数设置情况以及术中各呼吸参数与术后肺部并发症关系。
方 法
本试验数据全部来源于LAS VEGAS研究。入选标准为接受全身麻醉机械通气的患者，排除标准包括年龄＜18岁、术前30天内曾有过机械通气、手术室外麻醉以及需要单肺通气或体外循环的手术患者、BMI＜30kg/m2的患者。主要观察患者术中通气及术后7天内肺部并发症的发生情况。
结 果
该研究共纳入29个国家135家中心的2012名患者，来自于欧洲、北美、北非、中东地区；平均潮气量为525ml，按实际体重计算为5.5ml/kg，按标准体重计算为8.8ml/kg。PEEP中位数为4cmH2O。接受肺复张的患者仅占总人数的13.8%（277/2012），而其中仅有一半的患者接受的是常规肺复张（55.6%，154/277）。11.7%（236/2012）的患者出现了至少一种术后肺部并发症（PPCs）。综合多变量相关分析表明：年龄，肥胖等级三级，存在阻塞性呼吸暂停，麻醉时长，气道峰压，临时肺复张和使用手法复张的常规肺复张与PPCs间存在相关性。而麻醉时长，阻塞性呼吸暂停以及临时肺复张与发生严重PPCs相关。
结 论
肥胖患者术中常常被使用较大的潮气量和较低的PEEP，而很少进行术中肺复张。肥胖患者术后肺部并发症的发生率较普通患者升高，并明显增加住院时间。年龄、阻塞性呼吸暂停、BMI≥40kg/m2、麻醉时长、高气道峰压、手法肺复张等因素与术后肺部并发症的发生相关性很高。
原始文献摘要
Ball L, Hemmes S N T, Neto A S, et al. Intraoperative ventilation
settings and their associations with postoperative pulmonary complications in obese patients. British Journal of Anaesthesia, 2018
[Abstract]
Background: There is limited information concerning the current practice of intraoperative mechanical ventilation in obese patients, and the optimal ventilator settings for these patients are debated. We investigated intraoperative ventilation parameters and their associations with the development of postoperative pulmonary complications (PPCs) in obese patients.
Methods: We performed a secondary analysis of the international multicentre Local ASsessment of VEntilatory management during General Anesthesia for Surgery’ (LAS VEGAS) study, restricted to obese patients, with a predefined composite outcome of PPCs as primary end-point.
Results: We analysed 2012 obese patients from 135 hospitals across 29 countries in Europe, North America, North Africa, and the Middle East. Tidal volume was 8.8 [25th-75th percentiles: 7.8-9.9] mlkg-1 predicted body weight,PEEP was 4 [1-5] cmH2O, and recruitment manoeuvres were performed in 7.7%of patients. PPCs occurred in 11.7% of patients and were independently associated with age (P＜0.001), body mass index 40 ≥kgm-2 (P=0.033),obstructive sleep apnoea (P=0.002), duration of anaesthesia (P＜0.001), peak airway pressure(P＜0.001)，use of rescue recruitment manoeuvres (P＜0.05) and routine recruitment manoeuvres performed by bag squeezing (P＝0.021)，PPCs were associated with an increased length of hospital stay (P＜0.001).
Conclusions: Obese patients are frequently ventilated with high tidal volume and low PEEP, and seldom receive recruitment manoeuvres. PPCs increase hospital stay, and are associated with preoperative conditions, duration of anaesthesia and intraoperative ventilation settings. Randomised trials are warranted to clarify the role of different ventilatory parameters in obese patients.
麻醉学文献进展分享
贵州医科大学高鸿教授课题组
编辑：符校魁 审校：余晓旭