Oral clonidine reduces the requirement of prostaglandin E1 for induced hypotension.
OBJECTIVE
To determine the effects of preanesthetic oral clonidine on the dose of prostaglandin EI (PGEI) required to produce hypotension during anesthesia.


METHODS
Oral placebo, 75 microg or 150 microg clonidine were administered 60 min prior to induction of anesthesia. Anesthesia was maintained with O2:N2O (30:70) and isoflurane 1.0%. After hemodynamic stabilization, an infusion of prostaglandin EI was started (0.05 microg x kg(-1) x min(-1)) and the rate of infusion was adjusted to maintain mean arterial pressure (MAP) between 60-70 mm Hg during operation.


RESULTS
Duration of hypotension in placebo, 75 microg and 150 microg preanesthetic oral clonidine treated groups were 132+/-46, 117+/-37 and 129+/-56 min, respectively. The PGEI requirement in each group were 1563+/-180 (28.6+/-3.2), 594+/-197 (10.8+/-3.6) and 283+/-30 (5.5+/-3.6) microg (microg x kg(-1)), respectively. In addition, blood loss in each group were 1461+/-389, 805+/-240 and 931+/-40 ml, respectively.


CONCLUSIONS
Preanesthetic oral clonidine decreased the dose of PGEI required to produce hypotension, and decreased the blood loss during operation.
Murakami
K
K
Department of Anesthesiology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
Mammoto
T
T
Kita
T
T
Imai
Y
Y
Mashimo
T
T
Kirita
T
T
Sugimura
M
M
Kishi
Y
Y
D000284:Administration, Oral; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D000527:Alprostadil / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007023:Hypotension, Controlled; D008875:Middle Aged
D000316:Adrenergic alpha-Agonists; D000527:Alprostadil; D003000:Clonidine