Objective: To demonstrate that the use of propofol 2% is comparable to propofol 1% in effectiveness and in the wake-up time used for prolonged sedation.
Design: Open-label, case cohort study with a cohort of historical controls, phase IV clinical trial.
Setting: Medical and surgical intensive care unit (ICU) in a community hospital.
Patients: Fifty-one consecutive patients (medical, surgical, and trauma) admitted to our ICU requiring mechanical ventilation for >24 hrs.
Methods: All patients received propofol 2% (1-6 mg.kg-1.hr-1, starting with the lowest dose) and morphine chloride (0.5 mg.kg-1.24 hrs-1). A 4-5 level of sedation (Ramsay scale) was recommended. When weaning was indicated clinically, sedation and analgesia were interrupted abruptly, mechanical ventilation was discontinued, and the patient was connected to a T-bridge.
Outcome measurements: Inability to attain the desired level of sedation with the highest dose rate of proposal, and hypertriglyceridemia >500 mg/dL, were considered therapeutic failure. The time between discontinuation of mechanical ventilation and extubation was measured. Those variables, as well as different items related to ICU cost, were compared between the study group and two historical groups sedated with propofol 1% and midazolam.
Results: The duration of sedation was 122.4 +/- 89.2 (sd) hrs for the propofol 2% group. The frequency of hypertriglyceridemia was 3.9% and 20.4% for the propofol 2% and the propofol 1% groups, respectively (p =.016). Therapeutic failure rates were 19.6% and 33.4% for the propofol 2% and propofol 1% groups, respectively (p =.127). The lower frequency of hypertriglyceridemia was associated with a higher number of patients reaching weaning. Weaning time was similar in the two propofol groups, 32.3 hrs ($1,744) for the propofol 2% group vs. 97.9 hrs ($5,287) for the midazolam group. Cost of sedation was $2.68 per hour for the midazolam group and $7.69 per hour for the propofol group. There was a favorable cost-benefit ratio for the propofol group, attributable to the shorter weaning time, although benefit was less than expected because higher doses of propofol 2% than propofol 1% were required during the first 48 hrs (p <.05).
Conclusions: The new propofol 2% preparation is an effective sedative agent and is safe because of the low frequency of associated hypertriglyceridemia. The shorter weaning time associated with the use of propofol 2% as compared with midazolam compensates for its elevated cost. The economic benefit of propofol 2% is less than expected because higher doses of propofol 2% than propofol 1% are required over the first 48 hrs.