Blank Randal S, Colquhoun Douglas A, Durieux Marcel E, Kozower Benjamin D, McMurry Timothy L, Bender S Patrick, Naik Bhiken I
From the Department of Anesthesiology (R.S.B., D.A.C., M.E.D., B.I.N.) and Department of Surgery (B.D.K.), University of Virginia Health System, Charlottesville, Virginia; Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia (T.L.M.); and Department of Anesthesiology, University of Vermont College of Medicine, Burlington, Vermont (S.P.B.).
Anesthesiology. 2016 Jun;124(6):1286-95. doi: 10.1097/ALN.0000000000001100.
The use of lung-protective ventilation (LPV) strategies may minimize iatrogenic lung injury in surgical patients. However, the identification of an ideal LPV strategy, particularly during one-lung ventilation (OLV), remains elusive. This study examines the role of ventilator management during OLV and its impact on clinical outcomes.
Data were retrospectively collected from the hospital electronic medical record and the Society of Thoracic Surgery database for subjects undergoing thoracic surgery with OLV between 2012 and 2014. Mean tidal volume (VT) during two-lung ventilation and OLV and ventilator driving pressure (ΔP) (plateau pressure - positive end-expiratory pressure [PEEP]) were analyzed for the 1,019 cases that met the inclusion criteria. Associations between ventilator parameters and clinical outcomes were examined by multivariate linear regression.
After the initiation of OLV, 73.3, 43.3, 18.8, and 7.2% of patients received VT greater than 5, 6, 7, and 8 ml/kg predicted body weight, respectively. One hundred and eighty-four primary and 288 secondary outcome events were recorded. In multivariate logistic regression modeling, VT was inversely related to the incidence of respiratory complications (odds ratio, 0.837; 95% CI, 0.729 to 0.958), while ΔP predicted the development of major morbidity when modeled with VT (odds ratio, 1.034; 95% CI, 1.001 to 1.068).
Low VT per se (i.e., in the absence of sufficient PEEP) has not been unambiguously demonstrated to be beneficial. The authors found that a large proportion of patients continue to receive high VT during OLV and that VT was inversely related to the incidence of respiratory complications and major postoperative morbidity. While low (physiologically appropriate) VT is an important component of an LPV strategy for surgical patients during OLV, current evidence suggests that, without adequate PEEP, low VT does not prevent postoperative respiratory complications. Thus, use of physiologic VT may represent a necessary, but not independently sufficient, component of LPV.
采用肺保护性通气（LPV）策略可能会将手术患者的医源性肺损伤降至最低。然而，确定理想的LPV策略，尤其是在单肺通气（OLV）期间，仍然难以实现。本研究探讨了OLV期间呼吸机管理的作用及其对临床结局的影响。
回顾性收集2012年至2014年期间接受OLV胸外科手术患者的医院电子病历和胸外科医师协会数据库中的数据。对符合纳入标准的1019例病例分析了双肺通气和OLV期间的平均潮气量（VT）以及呼吸机驱动压力（ΔP）（平台压-呼气末正压[PEEP]）。通过多变量线性回归研究呼吸机参数与临床结局之间的关联。
开始OLV后，分别有73.3%、43.3%、18.8%和7.2%的患者接受的VT大于预测体重的5、6、7和8 ml/kg。记录了184例主要结局事件和288例次要结局事件。在多变量逻辑回归模型中，VT与呼吸并发症的发生率呈负相关（比值比，0.837；95%可信区间，0.729至0.958），而当与VT一起建模时，ΔP可预测严重并发症的发生（比值比，1.034；95%可信区间，1.001至1.068）。
单纯低VT（即没有足够的PEEP）尚未明确显示有益。作者发现，很大一部分患者在OLV期间仍接受高VT，且VT与呼吸并发症的发生率和术后严重并发症呈负相关。虽然低（生理上合适）VT是手术患者OLV期间LPV策略的一个重要组成部分，但目前的证据表明，在没有足够PEEP的情况下，低VT并不能预防术后呼吸并发症。因此，使用生理VT可能是LPV的一个必要但并非独立充分的组成部分。
