M. Laesser et al., Angiotensin II blockade in existing hypovolemia: Effects of candesartan inthe porcine splanchnic and renal circulation, SHOCK, 14(4), 2000, pp. 471-477
Citations number
31
Categorie Soggetti
Aneshtesia & Intensive Care","Cardiovascular & Hematology Research
Angiotensin II (AngII) is an important vasoconstrictor during hypovolemia.
This study focused on the effects of the AngII receptor blocker candesartan
on intestinal, hepatic, and renal hemodynamics during severe hypovolemia w
hen administered in preexisting moderate hypovolemia, It was hypothesized t
hat specific AngII receptor blockade might enhance splanchnic perfusion dur
ing hypovolemia. Fasted, anesthetized, ventilated, juvenile pigs were hemor
rhaged by 20% of the blood volume for 30 min. Animals were then randomized
to receive candesartan (CAND, n = 11) or the vehicle (CTRL, n = 10) prior t
o further hemorrhage to 40% of the blood volume for 30 min. The shed blood
was then retransfused. Systemic and splanchnic hemodynamics were recorded i
ncluding intestinal mucosal, superficial and parenchymal hepatic, and corti
cal and medullary renal microcirculation by laser-Doppler flowmetry. Arteri
al blood gases were analysed. Candesartan-treated animals maintained mesent
eric and jejunal mucosal perfusion during 40% hypovolemia compared to CTRL
animals, while no differences were observed in the hepatic and renal circul
ation. Retransfusion restored mesenteric and renal blood flows despite pers
istent hypotension and reduced cardiac output in both CAND and CTRL animals
. Renal medullary and hepatic parenchymal microcirculation failed to recove
r during retransfusion in both CAND and CTRL animals. Arterial acidosis, hy
percarbia, and a negative base excess were observed in CTRL animals followi
ng retransfusion whereas those parameters were normalised in CAND animals.
Administration of candesartan in moderate hypovolemia ameliorated the reduc
tion and consequences of mesenteric and intestinal, but not hepatic perfusi
on during severe hypovolemia. No adverse effects were observed in the renal
circulation.