High-Flow Nasal Therapy Improves Dyspnea in Acute COPD Exacerbations

The use of high-flow nasal therapy (HFNT) may be an effective way to improve gas exchange, dyspnea, and the clearance of mucus in patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and bronchiectasis, according to the results of an analysis published in COPD: Journal of Chronic Obstructive Pulmonary Disease.

A single-center, single-arm, prospective, observational, feasibility study was conducted in patients admitted to the Respiratory Medicine Unit of AOU Policlinico-Vittorio Emanuele di Catania in Catania, Italy, for AECOPD and concomitant bronchiectasis.

This study was performed between September 2018 and October 2019. Inclusion criteria were the following: acute respiratory failure, which was defined as partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FIO₂) <300 mm Hg and arterial blood pH ≥7.35; respiratory rate (RR) of ≥26 breaths/min, despite having received maximum medical treatment and after receiving 1 hour of up to 10 L/m of oxygen via a face mask; COPD Global Initiative for Obstructive Lung Disease (GOLD) Class ≥2; Medical Research Council dyspnea score ≥2; and  history of documented bronchiectasis, as confirmed by a recent chest computed tomography scan in <1 year.

HFNT was delivered via use of a dedicated high-flow system initially set at a gas flow of 50 L/min. The HFNT interface was a nasal cannula. The HFNT settings were titrated according to the patient’s severity and tolerance, with the setting never falling below 35 L/min of the flow rate. Tolerance was assessed with the use of a visual analogue scale (VAS). HFNT interruption was carried out in patients who demonstrated severe hypoxemia (ie, PaO₂/FIO₂ <100 mm Hg) or the development of respiratory acidosis (pH <7.35) that required escalation of treatment (ie, noninvasive ventilation or intubation), as well as in patients who demonstrated an increase in dyspnea (ie, RR >30 breaths/min).

A total of 15 patients from a group of 82 screened individuals were enrolled in the study. After 24 hours of receiving HFNT, the participants demonstrated a significant improvement in dyspnea score on the Borg scale, from 6.7±1.4 to 4.1±1.3 (P <.001). Furthermore, RR decreased significantly from 29.6±2.7 breaths/min to 23.1±2.9 breaths/min (P <.001), PCO₂ decreased significantly from 58.4±13 to 51.6±8.2 (P =.001), and the quantity of mucus production increased significantly from 1.1±0.6 to 2.4±0.7 (P <.001).

None of the participants required the use of invasive or noninvasive mechanical ventilation. The overall VAS score for tolerance of HFNT was 6.5. No safety concerns with respect to the use of HFNT were reported.

The investigators concluded that because of the single-arm design of the current study, the effect of HFNT could not be isolated from the effect of standard pharmacologic treatment. Adequately powered and controlled studies are warranted to confirm these preliminary findings.

Reference

Crimi C, Noto A, Cortegiani A, et al. High flow nasal therapy use in patients with acute exacerbation of COPD and bronchiectasis: A feasibility study [published online February 24, 2020]. COPD. doi: 10.1080/15412555.2020.1728736