Use of oral clonidine for sedation in ventilated paediatric intensive care patients

Objectives. We aimed to document our experience with oral clonidine when used as a sedative in combination with intravenous morphine and lorazepam in a group of mechanically ventilated children with single-organ, respiratory failure. In particular, our objectives were to establish the relationship between oral dose, plasma concentration, and sedative effect, and second, to document the side-effect profile. Design. Prospective, cohort study over a 72-h period. Setting. Regional paediatric intensive care unit. Patients and participants. Twenty-four children were enrolled (median age 3 months) of whom ten were excluded (six due to extubation before 72 h, three sedation failures, one protocol violation). Measurements and results. Plasma clonidine was measured using gas chromatography mass spectrometry, and sedation assessed using the COMFORT score. Using a dose of 3-5 mug/kg every 8 h, plasma concentrations appeared to plateau at approximately 41 h giving a mean value of 1.38 ng/ml (95% confidence interval 1.0-1.8). Adequate sedation was achieved during 82% (837/1022 h) of the study period; however, this decreased to 70.3% when analysed on an intention-to-treat basis. There was a concomitant overall decrease in the average hourly requirements for both morphine (P = 0.02) and lorazepam (P = 0.003). There were no documented episodes of bradycardia, hypotension or hyperglycaemia. Conclusions. Oral clonidine may be a safe and effective sedative in combination with morphine and lorazepam for young children with single-organ, respiratory failure. This agent may also exhibit opioid and benzodiazepine sparing effects in this patient group. A full pharmacokinetic study is warranted.