Prognostic factors for extubation failure in high risk patients using high-flow nasal cannula

Introduction: High flow nasal cannula (HFNC) is effective in preventing extubation respiratory failure in high risk patients. However there is a lack of information in which variables better predict which patients will not benefit from this intervention. Objective: Our goal is to identify variables that could predict which patients will not benefit with HFNC for extubation failure prevention. Methods: Prospective interventional single center study in an intensive care unit in Argentina. We included patients with at least one pre-specified risk factor who required invasive mechanical ventilation (IMV) for more than 48hs and passed a spontaneous breathing trial. HFNC was administered for the first 24hs following extubation. We divided extubation failure causes into those related with worsening of respiratory variables and non-respiratory related causes. Results: We include 165 patients. 40(24.2%) presented extubation failure, 18(10.9%) of which were for non-respiratory related causes and 22(13.3%) for worsening of respiratory variables. None of the pre-specified risk factors individually or combine between this were associated with extubation failure. The median of days of IMV prior to extubation was the only variable associated with extubation failure (5(3-6) vs 4(3-5), p=0.02) in the failure and success group respectively. Conclusions: Incidence of extubation failure in high risk patients receiving HFNC for extubation failure prevention was similar to that reported in previous trials. None of the pre-specified risk factors predicted extubation failure. Time of IMV prior to extubation was the only variable associated with extubation failure.