Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2020 Jun;157(6):1455-1465.
doi: 10.1016/j.chest.2019.12.028. Epub 2020 Jan 23.

Effect of Olfactory Stimulation by L-Menthol on Laboratory-Induced Dyspnea in COPD

Masashi Kanezaki  1 , Kunihiko Terada  2 , Satoru Ebihara  3
Affiliations
Randomized Controlled Trial

Effect of Olfactory Stimulation by L-Menthol on Laboratory-Induced Dyspnea in COPD

Masashi Kanezaki et al. Chest. 2020 Jun.

Abstract

Background: Inhalation of L-menthol as a transient receptor potential melastatin 8 agonist induces a cooling sensation in the airway. This cooling sensation induced through olfactory stimulation by L-menthol (OSM) alleviates dyspnea in healthy humans. Therefore, we investigated effects of OSM on the neural respiratory drive (NRD) and multidimensional aspects of dyspnea induced by inspiratory resistive loaded breathing in COPD.

Methods: In total, 28 patients with COPD and 14 control participants were included in this randomized, single-blinded, placebo-controlled, crossover study. OSM was administered using an L-menthol-scented patch, whereas placebo was administered using olfactory stimulation by strawberry-scented patch: placebo (OSP). Sham condition was measured by breathing through a face mask without a OSP. Dyspnea was evoked by breathing through the inspiratory resistance of 20 or 30 cm H2O/L/s and measured using the Multidimensional Dyspnea Profile. NRD was estimated using the electromyogram activities of the parasternal intercostal muscles.

Results: Compared with sham and OSP, OSM did not alter the breathing pattern/timing and NRD during inspiratory resistive loading; however, it significantly alleviated the physical and mental breathing effort, air hunger, breathing discomfort, anxiety, and fear during inspiratory resistive loaded breathing in patients with COPD. However, although OSM reduced the air hunger, mental breathing effort, and unpleasantness, no significant improvement on affective dimension of dyspnea by OSM was observed in control participants.

Conclusions: Our findings suggest that OSM activated the sense of inspiratory flow that achieved dyspnea relief in patients with COPD.

Trial registry: UMIN Clinical Trials Registry (UMIN-CTR); No.: UMIN000033822; URL: https://www.umin.ac.jp/ctr/index.htm.

Keywords: COPD; L-menthol; TRPM8; cognition of inspiratory flow; dyspnea.

PubMed Disclaimer

Comment in

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

Associated data