Vieillard-Baron Antoine, Prin Sebastien, Chergui Karim, Page Bernard, Beauchet Alain, Jardin François
Medical Intensive Care Unit, University Hospital Ambroise Paré, Assistance Publique Hôpitaux de Paris, 9 avenue Charles de Gaulle, 92104, Boulogne Cedex, France.
Intensive Care Med. 2003 Nov;29(11):1929-35. doi: 10.1007/s00134-003-1938-1. Epub 2003 Aug 16.
Evaluation of low-flow pressure-volume loop at the bedside in ARDS, as an aid to assess recruitment produced by PEEP.
Low-flow pressure-volume loop at the bedside were obtained on the first day of respiratory support in 54 successive pulmonary ARDS patients (49 of whom had pneumonia) treated between April 1999 and June 2002. From the loop obtained at ZEEP, we determined manually the lower inflexion point (LIP). By superimposing the pressure-volume loop at ZEEP and at PEEP, we evaluated recruitment obtained at a constant elastic pressure of 20 cm H2O.
We observed two different types of loops, according to the pattern of the inflation limb. In type 1 (38 cases) the inflation limb was characterized by an inflexion zone, resulting from a progressive or a sudden improvement in compliance. In type 2 (16 patients) the inflation limb was virtually linear, without significant improvement in compliance during inflation, which remained particularly low (26+/-9 cm H2O). Use of a low PEEP (6+/-2 cm H2O) produced a substantial recruitment in type-1 patients (74+/-53 ml), which was marginally improved by a higher PEEP (89+/-54 ml). In type 2, recruitment produced by PEEP was significantly lower (48+/-26 ml, p=0.006).
Pressure-volume loop at bedside confirmed that a low PEEP was sufficient to obtain recruitment in ARDS. This study also individualized a group of pulmonary ARDS patients exhibiting a markedly reduced compliance, in whom recruitment obtained by PEEP was limited.
在床边评估急性呼吸窘迫综合征（ARDS）患者的低流量压力-容积环，以辅助评估呼气末正压（PEEP）产生的肺复张效果。
对1999年4月至2002年6月期间连续治疗的54例肺部ARDS患者（其中49例患有肺炎）在呼吸支持的第一天获取床边低流量压力-容积环。从零呼气末正压（ZEEP）时获得的环中，我们手动确定下拐点（LIP）。通过叠加ZEEP和PEEP时的压力-容积环，我们评估在20 cm H₂O恒定弹性压力下获得的肺复张情况。
根据充气支的形态，我们观察到两种不同类型的环。在1型（38例）中，充气支的特征是有一个拐点区域，这是由于顺应性逐渐或突然改善所致。在2型（16例患者）中，充气支几乎呈线性，充气期间顺应性无明显改善，且仍然特别低（26±9 cm H₂O）。使用低PEEP（6±2 cm H₂O）在1型患者中产生了显著的肺复张（74±53 ml），较高的PEEP（89±54 ml）使其略有改善。在2型患者中，PEEP产生的肺复张明显较低（48±26 ml，p = 0.006）。
床边压力-容积环证实，低PEEP足以在ARDS中实现肺复张。本研究还区分出一组肺顺应性明显降低的肺部ARDS患者，在这些患者中，PEEP产生的肺复张有限。
