The polycompartment syndrome: towards an understanding of the interactions between different compartments!

Excerpt

Intensive Care Medicine presents the results of two clinical studies looking at the dynamic effects on central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), pleural pressure (Peso), and intra-abdominal pressure (IAP) caused by respiratory variations [1, 2]. The study by Bellemare et al. [1] examined simultaneous Peso, CVP, and PAOP tracings in 24 mechanically ventilated patients. The in- and expiratory changes in CVP and PAOP were found to be well correlated with changes in Peso. The bias was better for PAOP (2.2 ± 8.2 cmH₂O) than for CVP (2.9 ± 10.3 cmH₂O), but the limits of agreement were large, suggesting that they are not interchangeable. The lowest bias was observed with changes in PAOP with positive pressure (–0.05 ± 3.2 cmH₂O). The clinical importance of these results cannot be neglected. First, in analogy with functional hemodynamic monitoring, large respiratory swings in CVP or PAOP are correlated with fluid responsiveness [3, 4]. Second, the respiratory variations and especially the inspiratory fall in CVP or PAOP give an indication of the effort required to trigger the ventilator and are thus correlated with the work of breathing. Third, large inspiratory swings increase the afterload of the left ventricle which can result in pulmonary edema and respiratory failure postextubation. …