Objectives: To evaluate the comparative safety and effectiveness of intravenous infusion of propofol or midazolam when used for 12 to 24 hrs of sedation and to evaluate the quality of sedation during stimulation.
Design: An open, comparative, prospective, randomized study.
Setting: Surgical intensive care unit (ICU) in a university hospital.
Patients: Postoperative, intubated, general surgical, and orthopedic patients requiring mechanical ventilation (n = 60).
Measurements: Assessments were made at baseline (0 time), 5, 10, 15, 30, 45, and 60 mins; at 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 hrs; and at the end of sedation. The assessments included systolic, mean, and diastolic blood pressures, heart rate, two-lead electrocardiogram, pulse oximetry oxygen saturation, FIO2, end-tidal CO2, respiratory rate, ventilator rate, tidal volume, and sedation scale. Vital signs and the sedation scale were obtained at 30, 60, and 90 mins and at 2, 4, 12, and 24 hrs after the end of sedation. At approximately 8 hrs and 24 hrs (or at the end of sedation), the patient's CO2 production was calculated over a 5-min interval. Every 4 hrs, the nurse would summarize and rate patient response during stimulation as well as the overall rating of the sedation and patient ability to tolerate the ICU setting.
Main results: There were no significant differences in pulse oximetry, arterial blood gas values, or respiratory measurements during sedation with propofol or midazolam. The mean heart rate was slower in the propofol group throughout the sedation and postsedation periods. The rating of sedation and tolerance of the ICU environment were significantly better for the propofol-treated group. Postsedation, the propofol group woke up faster on discontinuation of the sedative.
Conclusions: Propofol was as safe and as efficacious as midazolam for continuous intravenous sedation. The quality of sedation was better in the propofol group.