Sedation during mechanical ventilation in infants and children: dexmedetomidine versus midazolam

We sought to compare the efficacy of midazolam versus dexmedetomidine for sedation during mechanical ventilation in infants and children.

We performed a prospective, randomized trial in a pediatric intensive care unit in a tertiary care center. Infants and children requiring mechanical ventilation underwent a continuous infusion of either midazolam (starting dose of 0.1 mg/kg/h) or dexmedetomidine (starting dose of either 0.25 or 0.5 microg/kg/h) with intermittent morphine, as needed. The efficacy of sedation was assessed using the Ramsay sedation scale, pediatric intensive care unit sedation score, and the tracheal suctioning score as well as bispectral monitoring.

There were 10 patients in each group. Sedation as assessed by the clinical sedation scores and the bispectral index was equivalent in the 3 groups. There were 36 morphine boluses administered to the midazolam group versus 29 and 20 morphine boluses administered respectively to the 0.25 and 0.5 microg/kg/h dexmedetomidine groups (P = 0.02 for midazolam versus 0.5 microg/kg/h dexmedetomidine). Total morphine use (mg/kg/24 h) was 0.74 +/- 0.5, 0.55 +/- 0.38, and 0.28 +/- 0.12 in the midazolam and the two dexmedetomidine groups respectively (P = not significant for midazolam versus 0.25 dexmedetomidine, P = 0.01 for midazolam versus 0.5 dexmedetomidine). In the two dexmedetomidine groups, 5 of 6 patients who at some point had a Ramsay score of 1 were less than 12 months of age while only 1 was more than 12 months of age (P < 0.05).

At a dose of 0.25 microg/kg/h, dexmedetomidine was approximately equivalent to midazolam at 0.22 mg/kg/h. At 0.5 microg/kg/h, dexmedetomidine provided more effective sedation as demonstrated by the need for fewer bolus doses of morphine, a decrease in the 24-hour requirements for supplemental morphine, as well as a decrease in the total number of assessment points with a Ramsay score of 1 (inadequate sedation) and the number of patients who had a Ramsay score of 1.