(1003) Impact of Spontaneous Awakening Trials on Mechanically Ventilated Patients Receiving Dexmedetomidine

Introduction: Dexmedetomidine (DEX) is a first-line sedative used during mechanical ventilation (MV), with known hemodynamic disturbances and potential withdrawal symptoms after prolonged exposure. Spontaneous awakening trials (SATs) have demonstrated improved outcomes for patients receiving sedation on MV, but their benefits in patients receiving DEX remains sparse . This study’s aim was to evaluate the impact of SATs on DEX exposure and clinical outcomes.

Methods: This retrospective study included adults receiving continuous DEX while on MV at an academic medical center before and after the introduction of the institution’s liberation bundle. Patients were excluded if they failed a safety screening required to perform an SAT. The primary endpoint was cumulative DEX exposure during the intensive care unit (ICU) stay amongst patients stratified into quartiles based on their receipt of an SAT. Secondary endpoints included MV duration, ICU length of stay (LOS), hospital LOS, all-cause mortality, self extubation rates, rescue medication use, and cumulative vasopressor exposure.

Results: After excluding 343 subjects for failing a pre-SAT safety screening, 200 patients were included in the study, with 100 subjects in each of the pre- and post- liberation groups. The cohort’s aggregate population was 66% female, with a mean age of 58, and an initial SOFA score of 9. No difference was detected among the groups regarding cumulative dexmedetomidine exposure (p=0.06), but those subjects who received ≥75% of possible SATs had a shorter median DEX duration compared to those with < 75% SAT adherence (76 hrs vs 124 hrs, p< 0.001). The pre-liberation group had a shorter LOS compared to the post-liberation group (20.7 vs 30.5 days, p-value=0.01), but a higher mortality (46% vs. 31, p=0.013) Rescue medications used for agitation were similar between the pre- and post-liberation and groups (73% vs 79%, p=0.32). No other secondary outcomes were different among the groups.

Conclusions: This study did not find a difference in DEX exposure based upon the receipt of an SAT. A lower mortality was observed in the post-liberation cohort, but confounding factors may be present. Future prospective studies are needed to determine if SATs impact specific outcomes of interest for patients receiving DEX.