Oral clonidine reduces the requirement of prostaglandin E1 for induced hypotension

Abstract

Purpose: To determine the effects of preanesthetic oral clonidine on the dose of prostaglandin EI (PGEI) required to produce hypotension during anesthesia. Method: Oral placebo, 75 μg or 150 μg 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 μg · kg-1 · min-1) and the rate of infusion was adjusted to maintain mean arterial pressure (MAP) between 60-70 mmHg during operation. Results: Duration of hypotension in placebo, 75 μg and 150 μg 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) μg (μg · kg-1), respectively. In addition, blood loss in each group were 1461 ± 389, 805 ± 240 and 931 ± 40 ml, respectively. Conclusion: Preanesthetic oral clonidine decreased the dose of PGEI required to produce hypotension, and decreased the blood loss during operation.