Six critically ill patients with clinical and hemodynamic signs of hypovolemia developed roentgenographic evidence of pulmonary edema (PE) without cardiac enlargement after infusion of an average of 6.4 liters of crystalloids.
Left ventricular filling pressures remained normal. However, colloid osmotic pressure (COP) decreased to 15 torr, substantially lower than the normal of 25 torr. The low COP may account for the development of PE in the absence of pulmonary hypertension occurring singly or concurrently with changes in interstitial pressure or capillary permeability.
(JAMA 229:65-68, 1974)