Division of Pulmonary and Critical Care Medicine, Hines Veterans Affairs Hospital, Hines, Illinois, and Stritch School of Medicine, Loyola University of Chicago, Maywood, Illinois.
Ann Am Thorac Soc. 2018 Feb;15(Suppl 1):S49-S52. doi: 10.1513/AnnalsATS.201705-417KV.
The primary purpose of mechanical ventilation is to decrease work of breathing. Achieving this goal requires that cycling of the ventilator be carefully aligned with the intrinsic rhythm of a patient's respiratory center output. Problems arise at the point of ventilator triggering, post-trigger inflation, and inspiration-expiration switchover. Careful, iterative adjustments of ventilator settings are required to minimize work of breathing. Use of protocols for the selection of ventilator settings can lead to complications (including alveolar overdistention) and risk of death. Because complications are axiomatic to mechanical ventilation, it should be discontinued at the earliest possible time. To shorten ventilator time, the critical step is to screen for weanability through use of weaning predictor tests. Use of T-tube trials circumvents the impossibility of estimating patient work of breathing during pressure support. Before extubation, patients should demonstrate the ability to breathe successfully in the absence of pressure support and positive end-expiratory pressure.
机械通气的主要目的是降低呼吸功。要实现这一目标，需要仔细调整呼吸机的循环与患者呼吸中枢输出的固有节律一致。问题出在呼吸机触发、触发后充气和吸气-呼气切换点。需要仔细、反复地调整呼吸机设置，以最大限度地降低呼吸功。使用呼吸机设置选择方案可能会导致并发症（包括肺泡过度膨胀）和死亡风险。由于机械通气必然会出现并发症，因此应尽早停止机械通气。要缩短呼吸机使用时间，关键步骤是通过使用脱机预测试验来筛查脱机能力。使用 T 管试验可以避免在压力支持下无法估计患者呼吸功的问题。拔管前，患者应在没有压力支持和呼气末正压的情况下成功呼吸。
