Regional blood flow redistribution during early burn shock in the guinea pig.

The distribution of blood flow was determined with radioactive microspheres following scald injury in guinea pigs. Burn was induced in halothane-anesthetized guinea pigs by a 3-sec immersion to the xiphoid process in 100 degree C water. Cardiac output and fractional blood flow measurements were made at preburn, 15-min postburn, and 75-min post-burn. In the scalded animals cardiac output decreased 58% by 75 min postburn. Three different blood flow responses to burn were noted: a) Brain, heart, hepatic artery, and adrenals received an increased fraction of the cardiac output; b) the fractional distribution of the diaphragm, liver (portal), spleen, gastrointestinal tract, muscle (from burned portion of the body), and bone remained constant; while c) the pancreas, burned skin, nonburned skin, and adipose tissue received a reduced fraction of the cardiac output. Although some regions of the body (i.e., brain and heart) received a greater percentage of the total cardiac output after burn injury, the cardiac output decrease was sufficient to cause a depression in absolute blood flow to all but two sites (adrenals and hepatic artery).