Efficacy and safety of early dexmedetomidine during noninvasive ventilation for patients with acute respiratory failure: a randomized, double-blind, placebo-controlled pilot study.

BACKGROUND

Successful application of noninvasive ventilation (NIV) for acute respiratory failure (ARF) requires patient cooperation and comfort. The efficacy and safety of early IV dexmedetomidine when added to protocolized, as-needed IV midazolam and fentanyl remain unclear.

METHODS

Adults with ARF and within 8 h of starting NIV were randomized to receive IV dexmedetomidine (0.2 μg/kg/h titrated every 30 min to 0.7 μg/kg/h to maintain a Sedation-Agitation Scale [SAS] score of 3 to 4) or placebo in a double-blind fashion up to 72 h, until NIV was stopped for ≥ 2 h, or until intubation. Patients with agitation (SAS ≥ 5) or pain (visual analog scale ≥ 5 of 10 cm) 15 min after each dexmedetomidine and placebo increase could receive IV midazolam 0.5 to 1.0 mg or IV fentanyl 25 to 50 μg, respectively, at a minimum interval of every 3 h.

RESULTS

The dexmedetomidine (n = 16) and placebo (n = 17) groups were similar at baseline. Use of early dexmedetomidine did not improve NIV tolerance (score, 1 of 4; OR, 1.44; 95% CI, 0.44-4.70; P = .54) nor, vs. placebo, led to a greater median (interquartile range) percent time either tolerating NIV (99% [61%-100%] vs. 67% [40%-100%], P = .56) or remaining at the desired sedation level (SAS score = 3 or 4, 100% [86%-100%] vs. 100% [100%-100%], P = .28], or fewer intubations (P = .79). Although use of dexmedetomidine was associated with a greater duration of NIV vs placebo (37 [16-72] vs. 12 [4-22] h, P = .03), the total ventilation duration (NIV + invasive) was similar (3.3 [2-4] days vs. 3.8 [2-5] days, P = .52). More patients receiving dexmedetomidine had one or more episodes of deep sedation vs placebo (SAS ≤ 2, 25% vs. 0%, P = .04). Use of midazolam (P = .40) and episodes of either severe bradycardia (heart rate ≤ 50 beats/min, P = .18) or hypotension (systolic BP ≤ 90 mm Hg, P = .64) were similar.

CONCLUSIONS

Initiating dexmedetomidine soon after NIV initiation in patients with ARF neither improves NIV tolerance nor helps to maintain sedation at a desired goal. Randomized, multicenter trials targeting patients with initial intolerance are needed to further elucidate the role for dexmedetomidine in this population.