The Relationship of Pulmonary Edema to Hydrostatic and Colloid Osmotic Pressures in Man

Abstract

Years ago Starling [8] demonstrated that the fluid movement between the capillaries and surrounding tissues was a function of five variables: (a) capillary permeability, (b) capillary hydrostatic pressure, (c) plasma colloid osmotic, (d) interstitial hydrostatic, and (e) interstitial colloid osmotic pressures. Subsequently, Guyton and Lindsey [3] studied specifically the relationship of intravascular forces, namely, capillary hydrostatic and plasma colloid osmotic pressures, to the development of pulmonary edema in dogs. In these experiments pulmonary edema occurred at left-atrial pressure levels of 24 mm Hg when the albumin concentration in the plasma was normal. After the albumin concentration was reduced to 47% of the control values, pulmonary edema appeared when left-atrial pressure was increased only above 11 mm Hg.