Failure of the colloid oncotic-pulmonary artery wedge pressure gradient to predict changes in extravascular lung water.

Colloid oncotic pressure (COP), pulmonary artery wedge pressure (WP), and the COP-WP gradient were measured in seven critically ill adult patients and compared with extravascular lung water determined using the thermal-dye double-indicator dilution technique and a bedside lung water computer. Correlation coefficients for changes in extravascular lung water vs. COP, WP, and COP-WP were not significant, and in this patient population the COP-WP gradient did not predict changes in extravascular lung water.