High Flow Oxygen Therapy at Two Initial Flow Settings versus Conventional Oxygen Therapy in Cardiac Surgery Patients with Postextubation Hypoxemia: A Single-Center, Unblinded, Randomized, Controlled Trial

Abstract

In cardiac surgery patients with pre-extubation PaO2/inspired oxygen fraction (FiO2) 2 = 0.6), intervention group 2 (HFNC initial flow = 40 L/min, FiO2 = 0.6), or control group (Venturi mask, FiO2 = 0.6). The primary outcome was occurrence of treatment failure. The baseline characteristics were similar. The hazard for treatment failure was lower in intervention group 1 vs. control (hazard ratio (HR): 0.11, 95% CI: 0.03–0.34) and intervention group 2 vs. control (HR: 0.30, 95% CI: 0.12–0.77). During follow-up, the probability of peripheral oxygen saturation (SpO2) > 92% and respiratory rate within 12–20 breaths/min was 2.4–3.9 times higher in intervention group 1 vs. the other 2 groups. There was no difference in PaO2/FiO2, patient comfort, intensive care unit or hospital stay, or clinical course complications or adverse events. In hypoxemic cardiac surgery patients, postextubation HFNC with an initial gas flow of 60 or 40 L/min resulted in less frequent treatment failure vs. conventional therapy. The results in terms of SpO2/respiratory rate targets favored an initial HFNC flow of 60 L/min.

Keywords

• high-flow nasal cannula
• cardiac surgery
• treatment failure
• respiratory rate
• oxygenation