Study Question: Does the early use of dexmedetomidine improve non-invasive ventilation (NIV) tolerance?
Study Description: This prospective, multicenter, randomized, double-blind, placebo controlled study evaluated consecutive ICU patients with acute respiratory failure (ARF) receiving NIV for ≤ 8 hours for inclusion.
Patients were randomized to receive placebo or dexmedetomidine infusion at 0.2 mcg/kg/hr titrated every 30 minutes (max 0.7 mcg/kg/hr) to maintain a Sedation-Agitation Scale (SAS) of 3-4. Fifteen minutes after a dexmedetomidine/placebo rate increase, both groups could receive ‘as needed’ doses of midazolam (for SAS ≥ 5), fentanyl IV (for a visual analogue scale (VAS) ≥ 5/10) and/or haloperidol (for a positive Intensive Care Delirium Screening Checklist [ICDSC]). The primary objective was NIV tolerance based on a modified 4-point NIV tolerance scale (range of 1 [tolerance] to 4 [severe intolerance]).
Results: Thirty-six of the 61 patients evaluated were randomized. Baseline characteristics were similar in each group, including pneumonia as the main cause of ARF, the initial NIV settings, and time from start of NIV to study drug initiation of approximately 4 hours. Six (38%) patients receiving dexmedetomidine and five (29%) receiving placebo were considered intolerant to NIV at baseline (p = 0.72). The duration of NIV was longer in the dexmedetomidine group (37 [16-72] vs. 12 [4-22] hours; p = 0.03) though the rate of intubation (31% vs. 29%, p = 0.80) and length of invasive ventilation (1.7 [1-3] vs. 3.4 [2-5] days, p = 0.12) were similar among both groups. Rates of NIV failure were similar between groups (dexmedetomidine 31% vs. placebo 29%, p = 0.80). The use of ‘as needed’ midazolam, fentanyl, and haloperidol was minimal and not significantly different between groups. Less than 50% in both groups required any ‘as needed’ medication. No patients developed severe hypotension or bradycardia.
Conclusion(s): The early use of dexmedetomidine did not improve tolerance or help to maintain desired sedation level in patients with ARF requiring NIV.
Perspective: Based on this study’s results, it appears that the early use of dexmedetomidine does not improve tolerance while on NIV and should not be used in a prophylactic nature. This study looked at all patients initiated on NIV, regardless of NIV tolerance at time of study drug initiation. Subgroup analysis, while not adequately powered to evaluate, indicates that dexmedetomidine may play a role in patients who become intolerant to NIV. Lastly it is important to note that this is a non-edited, online first publication. Significant changes may be made prior to official publication.