Jardin F, Brun-Ney D, Cazaux P, Dubourg O, Hardy A, Bourdarias J P
Intensive Care Unit, Hôpital Ambroise Paré, Boulogne, France.
Cathet Cardiovasc Diagn. 1989 Apr;16(4):215-20. doi: 10.1002/ccd.1810160402.
Simultaneous recordings of airway pressure, pleural pressure, and right ventricular (RV) pressure were obtained during mechanically controlled ventilation in a group of patients requiring respiratory support. Changes in transpulmonary pressure (calculated as airway pressure minus pleural pressure) were measured at end-expiration and end-inspiration during intermittent positive pressure ventilation with or without the application of a positive end-expiratory pressure, and were related to RV isovolumetric pressure changes at the onset of systole. It was found that any increase in transpulmonary pressure by intermittent positive pressure ventilation, or positive end-expiratory pressure (PEEP), or both, was associated with a proportional increase in RV isovolumetric pressure change. Moreover, when lung volume was progressively increased by incremental increases in tidal volume or PEEP level, transpulmonary pressure and RV isovolumetric pressure changes were strongly and linearly correlated. These results suggest that: 1) RV isovolumetric pressure change might be used as an index of RV output impedance during respiratory support by mechanically controlled ventilation; and 2) lung inflation resulting from the use of a positive airway pressure during respiratory support can increase RV output impedance and thereby contribute to the decrease in RV stroke output.
在一组需要呼吸支持的患者进行机械控制通气期间，同步记录气道压力、胸膜压力和右心室（RV）压力。在间歇正压通气期间，无论是否应用呼气末正压，在呼气末和吸气末测量跨肺压变化（计算为气道压力减去胸膜压力），并将其与收缩期开始时的RV等容压力变化相关联。结果发现，通过间歇正压通气、呼气末正压（PEEP）或两者使跨肺压增加，均与RV等容压力变化成比例增加相关。此外，当通过潮气量或PEEP水平的递增使肺容积逐渐增加时，跨肺压和RV等容压力变化呈强线性相关。这些结果表明：1）在机械控制通气的呼吸支持过程中，RV等容压力变化可作为RV输出阻抗的指标；2）在呼吸支持期间使用气道正压导致的肺膨胀可增加RV输出阻抗，从而导致RV每搏输出量减少。
