High-flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary diseases with acute-moderate hypercapnic respiratory failure: a randomized controlled trial of non-inferiority / 中华急诊医学杂志

ABSTRACT

Objective:To compare the efficacy of high-flow nasal cannula oxygen therapy (HFNC) and non-invasive ventilation (NIV) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with moderate typeⅡ respiratory failure, to clarify the feasibility of HFNC in the treatment of AECOPD, and to explore the influencing factors of HFNC failure.Methods:This study was a randomized controlled trial of non-inferiority. Patients with AECOPD with moderate type Ⅱ respiratory failure [arterial blood gas pH 7.25-7.35, partial pressure of arterial blood carbon dioxide (PaCO 2)> 50 mmHg] admitted to the Intensive Care Unit (ICU) from January 2018 to December 2021 were randomly assigned to the HFNC group and NIV group to receive respiratory support. The primary endpoint was the treatment failure rate. The secondary endpoints were blood gas analysis and vital signs at 1 h, 12 h, and 48 h, total duration of respiratory support, 28-day mortality, comfort score, ICU length of stay, and total length of stay. Multivariate logistic regression analysis was used to evaluate the failure factors of HFNC treatment. Results:Totally 228 patients were randomly divided into two groups, 108 patients in the HFNC group and 110 patients in the NIV group. The treatment failure rate was 29.6% in the HFNC group and 25.5% in the NIV group. The risk difference of failure rate between the two groups was 4.18% (95% CI -8.27%~16.48%, P=0.490), which was lower than the non-inferiority value of 9%. The most common causes of failure in the HFNC group were carbon dioxide retention and aggravation of respiratory distress, and the most common causes of failure in the NIV group were treatment intolerance and aggravation of respiratory distress. Treatment intolerance in the HFNC group was significantly lower than that in the NIV group (-29.02%, 95% CI -49.52%~-7.49%; P=0.004). After 1 h of treatment, the pH in both groups increased significantly, PaCO 2 decreased significantly and the oxygenation index increased significantly compared with baseline (all P < 0.05). PaCO 2 in both groups decreased gradually at 1 h, 12 h and 48 h after treatment, and the pH gradually increased. The average number of daily airway care interventions and the incidence of nasal and facial lesions in the HFNC group were significantly lower than those in the NIV group ( P < 0.05), while the comfort score in the HFNC group was significantly higher than that in the NIV group ( P=0.021). There was no significant difference between the two groups in the total duration of respiratory support, dyspnea score, ICU length of stay, total length of stay and 28-day mortality (all P > 0.05). Multivariate logistic regression analysis showed that acute physiology and chronic health evaluation Ⅱ score (≥15), family NIV, history of cerebrovascular accident, PaCO 2 (≥60 mmHg) and respiratory rate (≥32 times/min) at 1 h were independent predictors of HFNC failure. Conclusions:HFNC is not inferior to NIV in the treatment of AECOPD complicated with moderate type Ⅱ respiratory failure. HFNC is an ideal choice of respiratory support for patients with NIV intolerance, but clinical application should pay attention to the influencing factors of its treatment failure.