Nocturnal Nasal High-Flow Oxygen Effective in Comorbid OSA, COPD

Nocturnal nasal high-flow oxygen therapy (NHF-OT) significantly reduces obstructive episodes and improves oxygenation in elderly patients with concomitant obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD), according to a study in Sleep and Breathing.

Researchers sought to assess the overall effect of NHF-OT on obstructive events and nocturnal respiratory parameters in elderly patients with concomitant OSA and COPD, known as overlap syndrome (OS). The investigators compared standard nocturnal cardiorespiratory studies during NHF-OT vs low-flow conventional oxygen therapy (COT) in patients with OS and nocturnal respiratory failure who rejected treatment with positive airway pressure (PAP).

The study included patients older than 65 years of age with OSA, COPD, and nocturnal respiratory failure from a sleep laboratory in Catania, Italy, who were screened from January 2019 to July 2021. Nocturnal respiratory failure was defined as arterial oxygen saturation (SaO₂) below 90% (T90) for more than 30% of the time studied. All patients underwent overnight in-lab cardiorespiratory polygraphy. A total of 40 patients (22 male; mean [SD] age, 75.6 [7.0] years; mean body mass index, 29.3 [5.2 kg/m²]) were included.

NHF-OT was provided with a mean flow rate of 46.3 [9] L/min (range, 30-60), and resulted in a significant decrease in the apnea-hypopnea index (AHI) in all patients compared with baseline and with COT. The overall mean baseline AHI was 25.4 [8.6] and decreased to 19.4 [7] with COT and to 5.4 [4.6] (P <.001) with NHF-OT.

A response to NHF-OT, defined by researchers as an AHI of 5 or less, was seen in 19 of the 40 patients studied. Participants exhibiting a suboptimal response nevertheless showed improvement; their baseline mean AHI of 26.4 decreased during NHF-OT to 9.05 (P <.001).

At baseline, participants’ mean nocturnal SaO₂% was 86.2 [2.6]. At identical levels of fraction of inspired oxygen (FiO₂; mean value 27%), SaO₂% significantly increased to 91.8 [2.4] during COT and to 93.9 [2.5] during NHF-OT (P <.001). The T90% was 48.7 [20.1] at baseline and 16.8 [11.7] during COT and 8.8 [8.0] during NHF-OT (P <.001).

Notably, the mean flow rate in NHF-OT among those with an AHI of 5 or below (ie, responders) was 50.6 L/min, which was significantly higher than the flow rate of 42.7 L/min used for those with a higher AHI (ie, nonresponders) (P <.05).

Study limitations include the small sample size, the possibility that some predictive factors (such as the effect of sex/gender) were missed; and the fact that assessments were based on 1 night of data.

“Our data indicate that in elderly patients with overlap OSA-COPD and nocturnal hypoxemia who do not tolerate PAP, the nocturnal treatment with NHF-OT significantly reduces obstructive episodes and improves hypoxemia,” stated the study authors. “As the treatment is generally well tolerated compared to PAP, NHF-OT may be an alternative therapy in this subgroup of patients.”

This article originally appeared on Pulmonology Advisor