The effect of infrarenal aortic clamping and declamping on central haemodynamics and tissue blood flow in pigs--a comparison of fluid replacement between a colloid and a cristalloid.

A study has been undertaken to compare the effect of fluid administration of a cristalloid (Ringer glucose) with that of a colloid (dextran 40) on central haemodynamics and organ blood flow distribution during clamping and after declamping of infrarenal aorta in pigs. The declamping hypotension was significantly greater in the cristalloid group where a decrease in cardiac output was also seen. Tissue blood flow to the kidneys decreased in the cristalloid group during clamping but was maintained in the dextran group. At declamping there was a reactive kidney hyperaemia in the dextran group, while the medullar flow was still significantly decreased in the cristalloid group. The reactive hyperaemia seen in pancreas and small intestines was also greater in the dextran group.