High Flow Nasal Cannulas for Oxygenation: An Audit of Its Use in a Tertiary Care Hospital

Abstract

High flow nasal cannulas (HFNCs) provide humidified oxygen at higher flow rates and higher FiO2s than conventional delivery devices and are typically used in special care units. There is limited information on their use in general hospital settings. The medical records of all patients who were treated with HFNC during the calendar year 2014 were retrospectively reviewed to collect information on age, sex, indications, arterial blood gases when available, O2 saturations and outcomes. One hundred six patients received oxygen supplementation by HFNC in their hospital in 2014. The average age was 61.6 ± 16.2 years; 62 patients were men. The indications for HFNC included dyspnea (1 patient), hypoxemic respiratory failure (101 patients) and hypercapneic respiratory failure (4 patients). The PaO2 increased from 68.2 ± 16.3 mm Hg to 83.1 ± 32.2 mm Hg (N = 32, P = 0.02) with the change to HFNC. The O2 saturation increased from 93.1 ± 4.5% to 95.1 ± 3.0% (N = 106, P = 0.00015). The mean duration of use was 4.3 ± 3.7 days. Sixty-five patients did not require intubation or noninvasive ventilation (NIV). Sixteen required NIV, 16 required intubation and 9 required both. The overall mortality was 15%. HFNC oxygen therapy is used relatively frequently in their hospital on surgical and medical services. PaO2s and O2 saturations improved when patients were switched to this mode of oxygenation, but some patients subsequently required NIV and/or intubation. Patients on HFNC need careful monitoring for deterioration in their respiratory status.