Perioperative Positive Pressure Ventilation An Integrated Approach to Improve Pulmonary Care
Perioperative Positive Pressure Ventilation An Integrated Approach to Improve Pulmonary Care
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DOI：
10.1097/aln.0000000000000335
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发表时间：
2014-08-01
期刊：
影响因子：
8.8
通讯作者：
Jaber, Samir
中科院分区：
文献类型：
--
作者：
Futier, Emmanuel;Marret, Emmanuel;Jaber, Samir
5%至10%的手术患者以及高达30%至40%的胸部或腹部手术患者会出现术后肺部并发症(PPC)，这会增加风险、发病率、死亡率和医院护理成本。虽然机械通气(MV)是全身麻醉(GA)期间必不可少的支持性治疗，但它会在呼吸机开始时对肺功能正常的患者造成肺损伤。肺保护性通风是急性呼吸窘迫综合征(ARDS)患者的常规使用，但这种通风在肺部健康的患者中并不被广泛接受，特别是在手术室(OR)。本文讨论了机械通气在呼吸机相关性肺损伤(VALI)中的应用现状和发生机制，并提出了多方面的预防性围手术期正压通气(POP-VAUSING)方案，以防止围手术期肺衰竭和限制PPC的发生。MV期间采用高潮气量(VT；10-15毫升/公斤)来预防低氧血症和与低VT通气量相关的肺容量逐渐减少。然而，高VT通风的做法可能在手术室很普遍。呼气末正压(PEEP)不常用于OR，甚至肺保护方法(定义为预测体重的VT为8毫升/公斤和PEEP水平为5厘米H2O的组合)也只是偶尔使用。最近的证据表明，ARDS患者在手术中对肺保护呼吸策略的依从性较低，需要GA进行手术。不适当地使用MV会加重肺损伤，但在手术中短期暴露于MV的健康肺患者中，MV是否会损害肺部仍存在争议。然而，有明确的证据表明，GA促进肺容量的减少，这是肺不张发生的关键，而肺不张在术后仍存在。呼吸机相关性肺损伤可发生于高VT的充气肺泡区的周期性过度伸展和使用低VT或零PEEP反复关闭和打开肺单位，导致闭合和开放肺泡交界处的损伤(不张肺损伤)和应用过高的呼吸道压力(气压损伤)。它们中的每一种都可以在肺部引发炎症反应，或者可能启动和传播全身炎症介质的释放，导致全身器官功能障碍。一项实验研究发现，对肺部的不同侮辱可能会相互作用，导致比单独侮辱更多的炎性介质的产生和释放，这取决于它们的顺序。研究发现，当伤害性通风先于额外的侮辱时，炎症介质的释放更大，这表明机械通气是以后并发症的启动因素。许多已知的手术、麻醉相关和患者相关的危险因素存在于围手术期，可能与肺侵犯有关。最近一项关于预防性肺保护性通气对肺功能影响的研究显示，与高VT组相比，接受低VT通气组的患者术后前5天(Pod)的肺功能没有明显改善，尽管高VT组的气体交换更好；两组均使用低PEEP水平。低VT组无肺泡复张动作(RM)。麻醉诱导后重新开放肺不张需行复张操作，低VT时应采用PEEP，以防止进行性肺萎陷和通气量丧失。PEEP的最佳水平通常被认为大于5…
Five percent to 10% of all surgical patients and up to 30% to 40% having thoracic or abdominal surgery develop postoperative pulmonary complications (PPCs), which increase risks, morbidity, mortality, and costs for hospital care. Although mechanical ventilation (MV) is an essential supportive therapy during general anesthesia (GA), it can initiate lung damage in patients with healthy lungs at the beginning of ventilation. Lung-protective ventilation is used routinely in patients with acute respiratory distress syndrome (ARDS), but such ventilation is not widely accepted in patients with healthy lungs, particularly in the operating room (OR). This article discusses the current status of MV in the OR and the physiology of ventilator-associated lung injury (VALI) along with evidence supporting the implementation of a multifaceted bundle of prophylactic perioperative positive-pressure ventilation (the “POP-ventilation” bundle) to prevent lung collapse during the perioperative period and limit PPCs. High tidal volume (VT; 10–15 mL/kg) during MV is used to prevent hypoxemia and gradual loss of lung volume associated with low VT ventilation. However, the practice of high VT ventilation may be prevalent in the OR. Positive end-expiratory pressure (PEEP) is not commonly used in the OR, and even a lung-protective approach (defined as the combination of a VT of< 8 mL/kg predicted body weight [PBW] and a PEEP level of> 5 cm H2O) is used only sporadically. Recent evidence indicates that intraoperative adherence to lung-protective ventilation strategies is low in patients with ARDS and requiring GA for surgery. Inappropriate use of MV can exacerbate lung injury, but whether MV damages the lungs in patients with healthy lungs exposed to short-term MV during surgery is still controversial. Yet, evidence is clear that GA promotes reduction in lung volume, a key to the development of atelectasis, which remains during the postoperative period. Ventilator-associated lung injury can develop from cyclic overstretching of aerated alveolar areas with high VT and repeated closing and opening of lung units with the use of low VT or zero PEEP, leading to damage at the junction of closed and open alveoli (atelectrauma) and from the application of excessive airway pressures (barotrauma). Each of these can trigger an inflammatory reaction in the lungs or may initiate and propagate systemic release of inflammatory mediators, causing systemic organ dysfunction. One experimental study found that different insults to the lungs may interact to cause greater production and release of inflammatory mediators than either insult alone and is dependent on their sequence. The study found that release of inflammatory mediators was greater when injurious ventilation preceded additional insults, suggesting that MV is the priming factor for later complications. Many known surgical, anesthesiarelated, and patient-related risk factors are present during the perioperative period and may be responsible for lung aggression. A recent study on the pulmonary effects of prophylactic lung-protective ventilation failed to show any notable benefit in postoperative lung function during the first 5 postoperative days (PODs) in patients receiving low VT ventilation compared with those receiving high VT, although gas exchange was better with high VT; low PEEP levels were used in both groups. The low VT group had no alveolar recruitment maneuver (RM). Recruitment maneuvers are necessary to reopen atelectasis after anesthesia induction, and PEEP should be used with lower VT to prevent progressive lung collapse and loss of aeration. The optimal level of PEEP is generally considered to be greater than 5 …