Sedation of children requiring artificial ventilation using an infusion of midazolam.

The sedation of 50 children aged 6 months to 9 years who had undergone open heart surgery was studied. During artificial ventilation a midazolam infusion was used in conjunction with the administration of morphine (and tubocurarine). Sedation for patients breathing spontaneously with positive airway pressure was continued with midazolam alone. The duration of the midazolam infusion (2-6 micrograms kg-1 min-1) ranged from 12 to 197 h. Forty-seven of the children were sedated uneventfully; the remaining three children needed small doses of other sedative agents. In 10 of the children, blood samples were taken for serum midazolam assay and a short Synacthen test was performed. There was no clinical evidence of accumulation of midazolam, but midazolam concentrations were so variable that no conclusions could be drawn. All patients in whom they were measured (n = 10) had high basal cortisol concentrations, but displayed normal responses to Synacthen.