Punt C D, Schreuder J J, Jansen J R, Hoeksel S A, Versprille A
Atrium Medisch Centrum, Department of Anaesthesiology, Heerlen, The Netherlands.
Intensive Care Med. 1998 Aug;24(8):821-8. doi: 10.1007/s001340050672.
The aim of this study was to show the feasibility of a slow, continuously increasing level of positive end-expiratory pressure (PEEP) (ramp manoeuvre) in selecting best PEEP and to evaluate whether best PEEP, as defined by maximal oxygen transport, coincides with best systemic arterial oxygenation or best compliance.
In 11 anaesthetized piglets, PEEP was increased between 0 cmH2O (zero end-expiratory pressure; ZEEP) and 15 cmH2O (PEEP15) with a constant rate of 0.67 cmH2O x min(-1). This ramp manoeuvre was performed both under normal conditions and after induction of an experimental lung oedema. During the ramp manoeuvre, haemodynamic and pulmonary variables were monitored almost continuously.
During the rise in PEEP, cardiac output declined in a non-linear way. In the series with normal conditions, best PEEP was always found at ZEEP. In the series with experimental lung oedema, best PEEP, as defined by maximum oxygen transport, was found at PEEP1-6, as defined by maximal compliance, at PEEP7.5 and by maximal arterial oxygen tension (PaO2) at PEEP10-14.
Best PEEP according to oxygen transport is lower than best PEEP according to compliance and PaO2; the use of PEEP as a ramp might prevent unnecessarily high levels of PEEP.
本研究旨在表明在选择最佳呼气末正压（PEEP）时采用缓慢、持续增加的PEEP水平（斜坡操作）的可行性，并评估根据最大氧输送定义的最佳PEEP是否与最佳体循环动脉氧合或最佳顺应性一致。
在11只麻醉仔猪中，将PEEP从0 cmH₂O（呼气末零压力；ZEEP）以0.67 cmH₂O×min⁻¹的恒定速率增加至15 cmH₂O（PEEP15）。该斜坡操作在正常条件下以及诱导实验性肺水肿后均进行。在斜坡操作期间，几乎持续监测血流动力学和肺变量。
在PEEP升高期间，心输出量呈非线性下降。在正常条件组中，最佳PEEP始终在ZEEP时发现。在实验性肺水肿组中，根据最大氧输送定义的最佳PEEP在PEEP1 - 6时发现，根据最大顺应性定义的最佳PEEP在PEEP7.5时发现，根据最大动脉血氧分压（PaO₂）定义的最佳PEEP在PEEP10 - 14时发现。
根据氧输送的最佳PEEP低于根据顺应性和PaO₂的最佳PEEP；将PEEP作为斜坡使用可能会防止PEEP水平过高。
