[Effects of angiotensin II receptor antagonist on intestinal mucosal oxygenation during canine isovolemic hemodilution with hydroxyethyl starch].
BACKGROUND
Although isovolemic hemodilution can be used clinically to reduce the need for blood transfusion, the critical hemoglobin level and severe indequacy of tissue oxygenation induced by hemodilution remain unknown.


METHODS
Anesthetized dogs were submitted to graded hemodilution (20% and 40% blood volume reductions of estimated circulating blood volume) replaced with 10% hydroxyethyl starch. The effect of angiotensin II receptor (AT-II) antagonist, candesartan, on the intestinal mucosal oxygenation was assessed by tonometric method.


RESULTS
The splanchnic blood flow, measured by transit-time flow meters, and intestinal mucosal oxygenation were maintained well during 20% blood volume reduction without AT-II antagonist. By severe blood volume reduction, however, inadequate oxygenation was observed without, but not with AT-II antagonist.


CONCLUSIONS
These results suggest the protective effect of AT-II antagonist on intestinal perfusion during severe isovolemic hemodilution. Further investigation will be needed in patients undergoing major surgery with large anticipated blood loss.
Hayashi
Kenji
K
Department of Intensive & Critical Care Medicine, Dokkyo University School of Medicine, Tochigi 321-0293.
D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001810:Blood Volume; D004285:Dogs; D006438:Hemodilution; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000098:blood supply; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D012039:Regional Blood Flow
D057911:Angiotensin Receptor Antagonists; D006895:Hydroxyethyl Starch Derivatives; D010100:Oxygen