Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.
Curr Opin Pulm Med. 2012 Jul;18(4):359-65. doi: 10.1097/MCP.0b013e32835395ef.
Pleural effusions are prevalent in mechanically ventilated patients, and clinicians frequently consider draining the effusions. It is controversial whether patients benefit from pleural drainage in terms of either physiological or clinical outcomes.
Pleural drainage may be undertaken for a variety of reasons. Effusions are an important potential source of infection in patients with undifferentiated sepsis. Pleural drainage may improve hypoxemia or lung mechanics, but the physiological response depends on a complex interplay between lung and chest wall compliance, applied positive end-expiratory pressure and drainage volume. Pleural effusions may be associated with significant cyclic lung recruitment and collapse during tidal ventilation. Because effusions are primarily accommodated by descent of the diaphragm, they can also impair diaphragm mechanics significantly. There is very limited data in the literature to support the use of pleural drainage to accelerate liberation from mechanical ventilation, and there are no randomized controlled trials published to date.
Pleural drainage may benefit certain patient populations based on individual physiological considerations, but randomized controlled trials evaluating the impact on weaning outcomes are lacking. Future research efforts should focus on identifying patient populations most likely to benefit and clarify the mechanisms by which weaning may be accelerated after pleural drainage.
在机械通气患者中，胸腔积液很常见，临床医生经常考虑引流胸腔积液。胸腔积液引流是否能改善患者的生理或临床结局仍存在争议。
胸腔积液引流可能因多种原因而进行。在未明确诊断为败血症的患者中，胸腔积液是重要的潜在感染源。胸腔积液引流可能改善低氧血症或肺力学，但生理反应取决于肺和胸壁顺应性、呼气末正压和引流容量之间的复杂相互作用。胸腔积液在潮式通气期间可能导致明显的周期性肺复张和塌陷。由于胸腔积液主要通过膈肌下降来容纳，因此胸腔积液也会严重影响膈肌力学。目前文献中只有很少的数据支持胸腔积液引流可加速从机械通气中脱机，并且迄今为止还没有发表随机对照试验。
胸腔积液引流可能会使某些患者群体受益，这取决于个体的生理情况，但目前缺乏评估对脱机结局影响的随机对照试验。未来的研究应重点确定最有可能受益的患者人群，并阐明胸腔积液引流后脱机加速的机制。
