Objective: To compare isoflurane with midazolam for sedation of ventilated patients.
Design: Randomised control study. Setting--Intensive care unit in university teaching hospital.
Patients: Sixty patients aged 18-76 who required mechanical ventilation.
Interventions: Sedation with either 0.1-0.6% isoflurane in an air-oxygen mixture (30 patients) or a continuous intravenous infusion of midazolam 0.01-0.20 mg/kg/h (30 patients). Sedation was assessed initially and hourly thereafter on a six point scale. Incremental intravenous doses of morphine 0.05 mg/kg were given for analgesia as required. The trial sedative was stopped when the patient was judged ready for weaning from ventilatory support or at 24 hours (whichever was earlier).
End point: Achievement of a predetermined level of sedation for as much of the time as possible.
Main results: Isoflurane produced satisfactory sedation for a greater proportion of time (86%) than midazolam (64%), and patients sedated with isoflurane recovered more rapidly from sedation.
Conclusion: Isoflurane is a promising alternative technique for sedation of ventilated patients in the intensive care unit.