Prevention of Sevoflurane-Induced Agitation with Oral Clonidine Premedication

Abstract

To the Editor: We read with great interest the article by Kulka et al. (1) who concluded that IV clonidine prevents sevoflurane-induced agitation and suggested investigation into whether clonidine influences discharge-ready time. However, IV formulation is commercially unavailable in many countries, including the US and Japan. Thus, we present our previously collected data to support their conclusion and resolve the problem. After institutional approval and informed parental consent, children aged 2–11 yr undergoing minor (urological, ophthalmological, otological, and orthopedic) surgery received one of oral clonidine (2 or 4 μg/kg, up to 150 μg), midazolam (0.5 mg/kg, up to 10 mg), diazepam (0.4 mg/k, up to 10 mg), and placebo 30–60 min before anesthesia. Rectal diclofenac (12.5 or 25 mg) was given to each child immediately after induction of anesthesia, which was maintained with sevoflurane and nitrous oxide administered through an orotracheal tube. After anesthesia, the patients were transferred to wards. We blindly recorded agitation score during and after emergence from anesthesia (0 = sleep, 1 = calm, 2 = agitated but consolable, and 3 = severely agitated and inconsolable) and the time when children met discharge criteria (stable vital signs, ambulation, minimal bleeding, minimal pain, and minimal nausea/vomiting) (2) for determining home readiness. Oral clonidine 4 μg/kg reduced agitation scores; the other premedicants failed to do so (Table 1). These data strengthen the recent report by Kulka et al. (1). Clonidine did not prolong the time to meet home discharge criteria (Table 1). Oral clonidine premedication attenuates pain and emesis after pediatric anesthesia (3,4). These favorable properties may have offset possible extension of discharge ready time associated with postoperative sedative effects. Inclusion of the time to drink clear fluids in discharge criteria may have provided different results, although we believe that oral intake is not an absolute prerequisite for discharge from hospital. Our find- ings indicate that oral clonidine (4 μg/kg) premedication may be an alternative to intraoperative IV clonidine for the relief of sevoflurane-induced agitation without influencing discharge ready time in children.Table 1: Patient Characteristics, Agitation Score, and Discharge-Ready TimeKatsuya Mikawa, MD Kahoru Nishina, MD Makoto Shiga, MD