Capillary permeability in septic patients

It is suspected, but still unproven, that the increased capillary permeability which accompanies sepsis and contributes to the development of pulmonary edema (PE) involves systemic as well as pulmonary capillaries. We investigated the relationship between the colloid osmotic pressure of serum (COPS) and edema fluid (COPE) in 16 septic and 19 nonseptic patients with severe generalized edema. COPS values of septic and nonseptic patients were not significantly different (14.6 +/- 2.1 and 15.8 +/- 3.4 torr, respectively). However, the COPE of septic patients was 2.4 +/- 0.7 torr while the COPE of nonseptic patients was 1.3 +/- 0.7 torr. The COPE/COPS ratio was 0.165 in septic patients and 0.084 in nonseptic patients. Both of these differences are significant (p less than .001). It was also possible to discriminate septic from nonseptic patients on the basis of the COPE/COPS ratio. Thus, 16/17 determinations in septic patients had a ratio greater than .1, while 17/22 determinations in nonseptic patients showed a ratio less than .1. PE was present in 8/16 septic patients but in only 2/19 nonseptic patients. These data suggest that the increase in capillary permeability during sepsis is generalized.