Effects of dexmedetomidine on respiratory and hemodynamic changes in patients receiving high-flow nasal cannula: A retrospective observational study.

ObjectiveThe objective of this study was to evaluate the effects of dexmedetomidine on respiratory and hemodynamic parameters in patients receiving high-flow nasal cannula therapy.MethodsThis retrospective observational study included 206 adult patients who received dexmedetomidine during high-flow nasal cannula therapy between November 2019 and September 2023. Patients in whom dexmedetomidine was initiated during mechanical ventilation and those with incomplete data were excluded. Dexmedetomidine was administered intravenously at a median dose of 0.2 (0.2-0.3) mcg/kg/h for 3.0 (2.0-5.0) days. Primary outcomes were changes in respiratory rate and the partial pressures of carbon dioxide and oxygen. Secondary outcomes included hemodynamic changes, adverse events, and discontinuation of dexmedetomidine.ResultsRespiratory rate and the partial pressure of carbon dioxide remained stable over 24 h, whereas the partial pressure of oxygen significantly increased at 3 h (p = 0.007). Dexmedetomidine led to significant reductions in systolic blood pressure and heart rate (p < 0.001). Hypotension occurred in 31.6% of patients, and vasopressors were required in 28.2%. Dexmedetomidine was discontinued in 26.7% of patients because of adverse events.ConclusionsDexmedetomidine administration was associated with improved oxygenation without compromising respiratory drive in patients receiving high-flow nasal cannula, although careful monitoring is warranted because of potential hemodynamic effects.