By J. Brady Scott, PhD, RRT, RRT-ACCS, AE-C, FAARC, FCCP
Associate Professor, Program Director, College of Health Sciences, Department of Cardiopulmonary Sciences – Division of Respiratory Care, Rush University, Chicago
SYNOPSIS: In a prospective, single-center study, bronchodilators delivered in line with a high-flow nasal cannula device improved forced expiratory volume in one second and forced vital capacity in patients with chronic obstructive pulmonary disease exacerbation.
SOURCE: Colaianni-Alfonso N, MacLoughlin R, Espada A, et al. Delivery of aerosolized bronchodilators by high-flow nasal cannula during COPD exacerbation. Respir Care 2023;68:721-726.
With increased use of high-flow nasal cannula (HFNC) oxygen therapy in recent years, there has been a growing interest in bronchodilator delivery via the modality.1-4 Recently, Colaianni-Alfonso et al sought to evaluate the effectiveness of bronchodilators (anticholinergic and β-agonist) delivered in-line with HFNC in patients with chronic obstructive pulmonary disease (COPD) exacerbation. Patients in this study had a previous diagnosis of COPD and were admitted to an intermediate care unit and required noninvasive ventilation (NIV) for hypercapnic respiratory failure. All patients received bronchodilator therapy in-line with NIV from admission until they were stabilized. HFNC oxygen therapy was used when breaks from NIV were given.
After a washout period with no bronchodilators (≥ 6 hours), patients were given bronchodilators in-line with the HFNC device. A vibrating mesh nebulizer was used to aerosolize salbutamol (2.5 mg) and ipratroprium bromide (0.5 mg). Pulmonary function tests (forced expiratory volume in one second [FEV1] and forced vital capacity [FVC]) were performed before and 60 minutes after bronchodilator therapy. Two measures of FEV1 and FVC were performed with the HFNC device removed. The study’s primary outcome was FEV1 changes, with secondary outcomes being changes in FVC and clinical parameters, such as heart rate, SpO2, dyspnea, and breathing frequency.
Overall, 30 patients were included in the study, 23 of whom were classified as having severe COPD based on Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Before bronchodilator therapy, the mean ± standard deviation (SD) for FEV1 was 0.74 ± 0.10 L and after was 0.88 ± 0.12 L (P < 0.001). The FEV1 increased in 25 of 30 (83%) patients. Regarding FVC, there also was a significant pre- and post-bronchodilator (+ SD) increase from 1.75 ± 0.54 L to 2.13 ± 0.63 L (P < 0.001), respectively. There also were significant changes in heart rate and breathing frequency after bronchodilator therapy, but no differences in dyspnea and SpO2. The study authors concluded that bronchodilator therapy in line with HFNC and a vibrating mesh nebulizer showed mild but significant improvement in FEV1 and FVC. Further, they concluded that the decrease in breathing frequency might be attributable to less dynamic hyperinflation.
COMMENTARY
This study adds to the body of literature addressing bronchodilator use during HFNC oxygen therapy. Beuvon et al published similar findings in a physiologic crossover study in patients admitted to an intensive care unit for severe COPD exacerbation.5 In their study, they also noted a significant increase in FEV1, FVC, and peak expiratory flow. Additionally, they suggested a reduction in dynamic hyperinflation given the volume and flow improvement found during their study.
In 2021, a worldwide survey of HFNC oxygen therapy and concomitant aerosol therapy use revealed varying practices.4 Of the 1,014 participants who completed the study, only 24% reported delivering aerosol therapy in-line during HFNC oxygen therapy use. A higher percentage (40%) reported placing a nebulizer with a mask or mouthpiece during HFNC use, and some (30%) discontinued HFNC altogether to deliver medications using conventional aerosol devices. As stated by the authors, mounting evidence supports the effectiveness of transnasal pulmonary aerosol delivery, and administering aerosols through a mask or mouthpiece while using HFNC therapy has been discouraged.4,6 Studies indicate that this method reduces the inhaled dose significantly to as little as 10% of the dose achieved with transnasal aerosol delivery.4,7 Therefore, the concurrent use of a nebulizer with a mask or mouthpiece during HFNC should be avoided. Additionally, switching from HFNC to a conventional nebulizer interrupts HFNC therapy and does not improve aerosol delivery efficiency.4,6
More guidance is needed to address the delivery of bronchodilators in-line with HFNC oxygen devices. There is reasonable concern about the safety of this approach, given the high level of sinonasal deposition of aerosolized medications. Past studies evaluating aerosolized medications to the sinonasal passages have demonstrated rapid systemic absorption and increased delivery to the central nervous system.8 Further, given the different devices available on the market, more studies are needed to evaluate how device differences (design and settings) affect the transnasal delivery of HFNC oxygen therapy.
Although NIV is the established method for providing ventilatory support during COPD exacerbations, HFNC oxygen therapy serves as an alternative for certain patients who are unable to tolerate NIV or require breaks from NIV.5,9 Given the importance of bronchodilator therapy during COPD exacerbation, studies like the one conducted by Colaianni-Alfonso et al provide valuable insight into whether combining the therapies is feasible and effective. More studies and guidance are needed to inform clinicians about devices, device settings, and the overall safety of bronchodilators delivered in-line during HFNC oxygen therapy.
REFERENCES
- Li J, Albuainain FA, Tan W, et al. The effects of flow settings during high-flow nasal cannula support for adult subjects: A systematic review. Crit Care 2023;27:78.
- Papoutsi E, Giannakoulis VG, Xourgia E, et al. Effect of timing of intubation on clinical outcomes of critically ill patients with COVID-19: A systematic review and meta-analysis of non-randomized cohort studies. Crit Care 2021;25:121.
- Hess DR. Aerosol therapy during noninvasive ventilation or high-flow nasal cannula. Respir Care 2015;60:880-891.
- Li J, Tu M, Yang L, et al. Worldwide clinical practice of high-flow nasal cannula and concomitant aerosol therapy in the adult ICU setting. Respir Care 2021;66:1416-1424.
- Beuvon C, Coudroy R, Bardin J, et al. β agonist delivery by high-flow nasal cannula during COPD exacerbation. Respir Care 2022;67:9-15.
- Li J, Fink JB, MacLoughlin R, Dhand R. A narrative review on trans-nasal pulmonary aerosol delivery. Crit Care 2020;24:506.
- Bennett G, Joyce M, Fernández EF, MacLoughlin R. Comparison of aerosol delivery across combinations of drug delivery interfaces with and without concurrent high-flow nasal therapy. Intensive Care Med Exp 2019;7:20.
- Saunders JL, Davis MD. Transnasal aerosol delivery via HFNC: A question of safety and efficacy. Respir Care 2023;68:856-857.
- Radigan K. Management of COPD exacerbations in the ICU: What’s new? Crit Care Alert 2023;31:89-91.
