In vivo assessment of regional microvascular albumin leakage during E. coli septic shock in the baboon model.

Changes in regional microvascular albumin flux during septic shock were studied noninvasively by scintigraphy in the baboon model. Use was made of an i.v. injection of 99mTc-labelled baboon serum albumin. Count ratios of lung to cardiac, liver to cardiac, and abdominal to cardiac regions were measured every 2 hr for 6 hr in control and septic shock baboons, and compared. Increased ratios obtained during shock pointed to an increase in extravascular albumin. Linear regression lines fitted to these count ratios provided regional albumin leak indices. These indices demonstrated statistically significant increases (P less than 0.05) during septic shock for the abdominal region during the 6-hr study, and for all regions, but especially the abdomen, when data were calculated over 4 hr. Increasing ratios and leak indices correlated with postmortem data and changes in neutrophil and platelet behaviour previously established during shock.