Propofol Associated with a Shorter Duration of Mechanical Ventilation than Scheduled Intermittent Lorazepam: A Database Analysis Using Project Impact

Background: While one prospective controlled study in medical intensive care unit (ICU) patients demonstrated that sedation with propofol leads to a shorter duration of mechanical ventilation compared with scheduled intermittent intravenous lorazepam, its conclusions may not be applicable to surgical ICU patients and institutions not using daily sedation interruption. Objective: To compare the duration of mechanical ventilation between medical and surgical ICU patients receiving propofol versus scheduled intermittent lorazepam in routine clinical practice. Methods: Retrospective data (January 2001–December 2005) were obtained from the Project IMPACT database for medical and surgical ICU patients at Tufts-New England Medical Center, a 450 bed academic hospital. These patients had been mechanically ventilated for 24 hours or more and had received 24 hours or more of either propofol or scheduled intermittent lorazepam as the sole sedative. Clinically relevant variables were identified a priori, and their influence on duration of mechanical ventilation was evaluated. Differences in these variables between propofol and scheduled intermittent lorazepam groups within the ICU cohorts were then measured. Results: Of 4608 database patients, 287 met criteria. Factors associated with a prolonged duration of mechanical ventilation for the medical ICU cohort included sedation use for 5 or more days (OR 13.8; 95% CI 8.3 to 19.4), narcotic use (OR 7.6; 95% CI 2.3 to 13), and scheduled intermittent lorazepam use (OR 7.0; 95% CI 0.4 to 13.7). For the surgical ICU cohort, these factors included sedation use for 5 or more days (OR 15; 95% CI 11.4 to 19.4), APACHE II (Acute Physiology and Chronic Health Evaluation II) score equal to or greater than 18 (OR 4.1; 95% CI 0.4 to 7.8), and scheduled intermittent lorazepam use (OR 4.0; 95% CI 0.2 to 7.7). Duration of mechanical ventilation was the only variable that differed significantly between propofol and scheduled intermittent lorazepam in both the medical ICU, with a median (range) of 6 (3–12) versus 11 (5–25; p = 0.03), and surgical ICU, with a median of 4 (2–15) versus 9 (4–20; p = 0.001), groups. Conclusions: Sedation with propofol in the naturalistic setting appears to be associated with a shorter duration of mechanical ventilation compared with scheduled intermittent lorazepam in both medial and surgical ICU patients when only one sedative drug is used. Data from this uncontrolled observational study are consistent with findings from a randomized clinical trial.