Background: Respiratory care after cardiac surgery is a challenging area of medical treatment. High-flow nasal oxygen cannula (HFNC) may be used for reducing the reintubation rate.

Objective: The present study aimed to compare the use of HFNC with that of an incentive spirometer (IS) with respect to the reintubation rates in patients after cardiac surgery.

Materials and Methods: The authors conducted a prospective randomized controlled trial of 67 cardiac surgery patients. The HFNC group received the HFNC immediately after extubation performed within 24 hours, and the IS group received the IS with breathing exercises. Reintubation, length of intensive care unit, length of hospital stay, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂), partial pressure of carbon dioxide (PaCO₂), and peak expiratory flow rate (PEFR) were analyzed and compared.

Results: The reintubation rate was higher in the HFNC group, but the difference was not statistically significant (p=0.054). Hypoxia was the most common cause of intervention failure at 29.4% and 24.2% in the HFNC and IS groups, respectively. Four (11.8%) reintubated patients in the HFNC group later progressed to hospital-acquired pneumonia, which resulted in longer hospital stays (p=0.010). The PaO₂/FiO₂ ratio and PEFR decreased by 33.5% and 62.5%, respectively, on postoperative day 1 and improved the following day. The PaCO₂ was within the normal limits in both groups.

Conclusion: Compared to IS, prophylactic HFNC 24 hours after cardiac surgery increased the reintubation rate, but not significantly. The decision to administer prophylactic HFNC support after extubation in cardiac surgery patients should be contemplated on an individual basis.