Abstract
The changes in splanchnic organ blood flow and systemic hemodynamics during hypotensive anesthesia with adenosine triphosphate (ATP) or sodium nitroprusside (SNP) were studied. The study was done in 51 mongreal dogs anesthetized with 0.5% halothene and 50% nitrous oxide. They were devided into six groups by the hypotensive drugs and the level of blood pressure. In groupe 1, mean arterial blood pressure (MABP) was reduced 20% by intraveanous administration of ATP. In group 2, MABP was reduced 20% by ATP but dipyridamole (DP), adenosine uptake inhibitor was pretreated. In group 3, MABP was reduced 20% by SNP. Although the hypotensive drugs that were used in groups 1, 2, and 3 were used in groups 4, 5, and 6 again. But MABP was reduced 50% in the later groups. Blood flow was measured using the hydrogen gas clearance technique. The results were as follows: 1) The organ blood flow to renal cortex, renal medulla and spleen was decreased. But, the liver blood flow did not change significantly. In the organ blood flow, there was no significant difference between ATP and SNP hypotension. 2) These changes in organ blood flow during the hypotensive anesthesia were not only affected by perfusion pressure but also done by duration of hypotensive period. 3) Pretreatment of DP decreased the requirement dosage of ATP, and prevent deterioration of base excess. It indicates that deterioration of base excess is due to other factors besides tissue hypoperfusion.
