Dexmedetomidine as add-on sedation to reduce continuous infusion sedative use in mechanically ventilated patients

Purpose. To characterize the impact of add-on dexmedetomidine therapy on baseline continuous infusion sedative use. Methods. A retrospective, single-center, chart review-based study was conducted to assess outcomes of and potential predictors of response to add-on dexmedetomidine therapy in mechanically ventilated intensive care unit (ICU) patients who were already receiving continuous infusions of sedatives. Patients were defined as complete, partial, or nonresponders to add-on dexmedetomidine therapy if initial sedative infusion rates were reduced by 100%, by 50% to 99%, and by less than 50%, respectively, at 6 and 24 hours after initiation of dexmedetomidine. Results. Among the 100 patients included in the study sample, there were 54 complete responders, 21 partial responders, and 25 nonresponders to dexmedetomidine add-on therapy at 6 hours after dexmedetomidine initiation; at 24 hours, there were 65 complete and 12 partial responders and 23 nonresponders. Of the variables tested (ie, baseline characteristics, opioid and antipsychotic use, hemodynamic parameters), none differentiated between complete or partial responders and nonresponders. Ventilator time, ICU length of stay (LOS), and hospital LOS after add-on dexmedetomidine therapy initiation were shorter among both partial responders and complete responders vs nonresponders (median, 1.1 days vs 4.1 days [P = 0.01], 7.0 days vs 14.1 days [P = 0.20], and 11.0 vs 17.0 days [P = 0.58], respectively), with only ventilator time being significantly different. Conclusion. Add-on dexmedetomidine therapy can obviate or reduce the need for alternate sedation in as many as 75% of mechanically ventilated ICU patients. However, the addition of dexmedetomidine does not allow the reduction of alternate sedation in a substantial minority of patients, and failure to respond to dexmedetomidine can be identified as early at 6 hours after add-on therapy initiation. In the absence of clear predictors of response to dexmedetomidine, these data suggest empiric trials of dexmedetomidine can be considered but should be time-limited.