GABA-mediated sedatives have respiratory depressant properties that may be detrimental in patients with difficult airways. In this randomized, double-blind, multicenter, Phase IIIb Food and Drug Administration study, safety and efficacy of dexmedetomidine compared with placebo were evaluated as the primary sedative for awake fiberoptic intubation (AFOI). Patients were randomized to receive dexmedetomidine or saline. Patients were sedated with dexmedetomidine or rescue midazolam to achieve targeted sedation (Ramsay Sedation Scale ≥ 2) before topicalization and throughout AFOI. Primary efficacy endpoint was percentage of patients requiring rescue midazolam; secondary efficacy endpoints were total dose of rescue midazolam, percentage requiring additional rescue nonmidazolam medications, anesthesiologist's assessment of ease of subject care, and patient recall and satisfaction 24 hours postoperatively. Less rescue midazolam was required to maintain Ramsay Sedation Scale ≥2 (47.3% vs. 86.0%, P < 0.001), and supplemental midazolam dose was lower (1.07 ± 1.5 mg vs. 2.85 ± 3.0 mg, P < 0.001) with dexmedetomidine compared with placebo. More Mallampati Class IV patients treated with dexmedetomidine were successfully intubated without midazolam than with placebo (66.7% vs. 8.3%, P = 0.009). Dexmedetomidine decreased blood pressure and heart rate compared with placebo patients sedated with midazolam. Patients and anesthesiologists showed favorable satisfaction responses in both groups. Adverse events and patient recall were similar in both groups. Dexmedetomidine is effective as the primary sedative in patients undergoing AFOI. Some patients may require small supplemental doses of midazolam, in addition to dexmedetomidine, to achieve sufficient sedation for AFOI. Dexmedetomidine provides another AFOI option for sedation of patients with difficult airways.
Trial registration: ClinicalTrials.gov NCT00383890.