High-Flow Nasal Cannula Therapy for Acute Hypoxemic Respiratory Failure in Adults: A Retrospective Analysis

High-flow nasal cannula (HFNC) therapy is an oxygen delivery system. However, evidence regarding the clinical applications of HFNC is still emerging. We herein evaluated the clinical predictors of HFNC therapy success for adult patients with acute hypoxemic respiratory failure.

We retrospectively reviewed the medical records of the subjects with acute hypoxemic respiratory failure supported by HFNC therapy in the medical intensive care unit between July 2011 and March 2013. Therapy success was defined as the avoidance of intubation. The patients' baseline characteristics and the serial changes in the respiratory parameters after HFNC therapy at 1 and 24 hours were measured.

Of the 75 eligible patients, 62.7% successfully avoided intubation. Overall, HFNC therapy significantly improved the physiologic parameters, such as partial pressure of arterial oxygen (PaO2), saturation of arterial oxygen (SaO2), respiratory rate (RR), and heart rate (HR), throughout the first 24 hours. After the adjustment for the other clinical variables, Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), cardiogenic pulmonary edema, and PaO2 improvement at 1 and 24 hours were associated with therapy success. The overall intensive care unit (ICU) mortality was 25.3%. However, out of 37.3% of the patients who required intubation, the ICU mortality in this proportion of patients was 67.9%. The ICU mortality in the therapy failure group was associated with the use of a vasopressor and a limited PaO2 improvement at 1 hour.

HFNC therapy showed a good compliance and the improvement of the physiologic parameters in an adult population. The failure to improve oxygenation within 24 hours was a useful predictor of intubation. Among the failure group, the vasopressor use and failed oxygenation improvement were associated with ICU mortality.