Effect of nasal high-flow oxygen humidification on patients after cardiac surgery

Background Although high-flow humidified oxygen therapy (HFNC) has emerged as an important treatment for respiratory failure, few studies have reported on whether HFNC is appropriate for patients with hypoxemia after cardiac surgery, and the clinical efficacy of HFNC in patients undergoing cardiac surgery is unclear.Objective To investigate the clinical effect of HFNC after cardiac surgery.Methods Convenience sampling was used to select 76 patients who underwent invasive mechanical ventilation and oxygen therapy after valve replacement or coronary artery bypass grafting from July 2019 to June 2021. The patients were divided into the routine group and the HFNC group according to the oxygen therapy provided after the operation. The patients in the routine group (N = 38) were treated with oxygen inhalation by face mask after the operation, while those in the HFNC group (N = 38) were treated with HFNC via nasal cavity. The arterial partial pressure of oxygen (PaO2), the arterial partial pressure of carbon dioxide (PaCO2) and the oxygenation index (OI) were observed and compared between the two groups at 6 h, 12 h and 24 h after treatment. The sputum viscosity, incidence of second intubation and the intensive care unit (ICU) stay time were evaluated.Results The difference in PaCO2 between the two groups was statistically significant at 24 h after treatment (p < 0.05). The PaO2 in the HFNC group was significantly higher than in the routine group at 24 h after treatment, and the OI of the routine group was lower than in the HFNC group at 6 h, 12 h and 24 h after treatment (p < 0.05). The sputum viscosity in the HFNC group was better than in the routine group at 12 h and 24 h after treatment. The second intubation rate and ICU stay time in the HFNC group were lower than in the routine group (p < 0.05).Conclusion Compared with conventional mask oxygen inhalation, HFNC can effectively reduce sputum viscosity, improve oxygenation, reduce the incidence of repeated intubation and meet patients' comfort needs. It is an advantageous respiratory support strategy for patients after cardiac surgery compared with invasive mechanical ventilation to oxygen therapy and is beneficial to the recovery of cardiopulmonary function.