Estimation of pulmonary capillary pressure: different methods for different pathophysiological processes?

In the absence of a direct method with which to measure pulmonary capillary pressure in humans, various methods for analyzing the pulmonary artery pressure decay following balloon occlusion have been described. In this issue of Critical Care, Souza and coworkers investigate the adequacy of these methods for assessing various pathophysiological processes. They studied patients presenting with pathologies characterized by different distributions of pulmonary vascular resistance. Their findings suggest that no single method for estimating pulmonary capillary pressure is adequate for all disease processes.