HFNC May Improve AECOPD Prognosis Better Than Conventional Therapy

Physicians may consider high-flow nasal cannula (HFNC) as a first-line oxygen therapy in select patients with acute exacerbations chronic obstructive pulmonary disease (AECOPD), according to a study published in the International Journal of Chronic Obstructive Pulmonary Disease.

The study found that patients with AECOPD accompanied by hypercapnic respiratory failure had a better prognosis when they were on HFNC compared with conventional oxygen therapy (COT).

“…early use of HFNC in patients with AECOPD with acute compensated hypercapnic respiratory failure could alleviate respiratory muscle fatigue and improve CO2 retention, thereby reducing treatment failure,” wrote the investigators in the report.

COT, such as nasal catheter or venturi mask, is often used as the main respiratory support method for patients with AECOPD as an alternative to noninvasive mechanical ventilation (NIV), which can be uncomfortable and hard for patients to tolerate. HFNC is a new noninvasive respiratory support technique that delivers a conditioned, warmed, and humified air-oxygen mixture.

Investigators used a tricenter, prospective, randomized, controlled clinical trial to compare the safety and efficacy of HFNC with COT in 320 patients in Beijing, China, who were hospitalized with AECOPD with hypercapnic respiratory failure.

The patients, aged 40 years and older, were assigned randomly 1:1 to receive either HFNC (n = 160) or COT (n = 160) for at least 15 hours per day for at least 5 days. The study was conducted from June 2015 to July 2019.

The primary end point was treatment failure, meaning that a patient needed mechanical ventilation (either NIV or invasive mechanical ventilation [IMV]). The attending clinician made the decision of whether patients needed to switch to mechanical ventilation based on persistent or worsening dyspnea, persistent abdominal paradox, respiratory rate of more than 25 breaths per minute, and/or a pH of less than 7.35.

During the study, treatment failure occurred significantly less for patients receiving HFNC than COT, occurring in 10% (16) of patients in the HFNC group compared with 19.4% (31) patients in the COT group (P = .026). NIV was needed for 13 (8.1%) of the patients receiving HFNC and 26 (16.3%) of those who received COT. No patients required intubation or IMV interventions.

Additionally, the partial pressure of CO2 (PaCO2) of the HFNC group 24 hours after recruitment was lower than the COT group (54.1 ± 9.79 mmHg vs 56.9 ± 10.1 mmHg, P = .030). However, the investigators noted that PaCO2 higher than 59 mmHg after HFNC for 24 hours was an independent risk factor for treatment failure (odds ratio [OR] 1.078, 95% CI 1.006-1.154, P = 032).

“Therefore, we suggest that in addition to optimized COPD therapy, appropriate oxygenation devices should be used on select patients to achieve the most optimal outcome,” wrote the investigators.

Secondary end points of COPD assessment test (CAT) scores and subjective discomfort on the fifth day were significantly lower for patients in the HFNC group (16.3 ± 7.2 and 2.27 ± 1.06, respectively; P = .002) than those in the COT group (20.4 ± 5.7 and 3.88 ± 1.64, respectively; P < .001).

The lower CAT scores among patients in the HFNC group indicated “that HFNC may have the potential to improve the symptom of dyspnea in patients with AECOPD,” noted the investigators.

They also wrote that higher comfort scores for HFNC could lead to better treatment compliance for patients, which may have contributed to the lower rate of treatment failures compared with the COT group.

The most common side effects reported were condensate noise (26.3%), excessive or insufficient gas flow (23.1%), and high temperature (14.4%). The Investigators wrote that all of the side effects subsided after they adjusted the parameters or communicated with the participants.

“High-quality randomized controlled trials in large-scale cross-regional areas can further investigate the efficacy and safety of HFNC in a broader patient population with COPD exacerbation, which can also help identify the most appropriate patients and best practices,” the investigators concluded.

Reference

Li X-Y, Tang X, Wang R, et al. High-flow nasal cannula for chronic obstructive pulmonary disease with acute compensated hypercapnic respiratory failure: A randomized, controlled trial.Int J Chron Obstruct Pulmon Dis. 2020;2020(15):3051-3061. doi:10.2147/COPD.S283020