Clonidine facilitates controlled hypotension in adolescent children

In this randomized, double-blinded, placebo-controlled trial, we investigated whether clonidine lessened the requirements for isoflurane, fentanyl, and labetalol to provide controlled hypotension in children who underwent oromaxillofacial surgery. We also studied preoperative sedative effects, the hemodynamic response to nasotracheal intubation, and recovery characteristics. Thirty-nine healthy children, aged 10-16 yr, received clonidine 5 μg/kg or placebo on the night before surgery and 90 min before surgery. By self-assessment, children in both groups showed similar anxiety, whereas observers rated clonidine patients as more sedated (P < 0.01). Heart rate during induction remained significantly decreased in clonidine patients compared with placebo patients (P < 0.001), as did arterial blood pressure before induction (P < 0.01) and peak pressure after intubation (P < 0.001). Children who took clonidine required significantly less isoflurane to maintain a mean arterial blood pressure of 60 ± 4 mm Hg (mean isoflurane concentration, clonidine 0.99% versus placebo 1.33; P = 0.0004) and required less fentanyl than placebo patients (P = 0.002). Fewer treatment patients received labetalol (clonidine, n = 3 versus placebo, n = 13; P = 0.004). There was a trend toward faster recovery in the clonidine group, with a shortened recovery room stay (P = 0.03). We conclude that clonidine is a useful adjunct for controlled hypotension in children.