Inhaled Nitric Oxide (iNO) in Idiopathic Pulmonary Fibrosis (IPF).

Summary

Idiopathic Pulmonary Fibrosis (IPF) is a progressive lung disease marked by reduced exercise capacity and activity-related breathlessness (commonly termed dyspnea). Our previous work has shown that dyspnea during exercise is associated with an increased drive to breathe (inspiratory neural drive; IND). However, little work has been done to understand the mechanisms of exertional dyspnea in patients with mild IPF. The objectives of this study are to compare the acute effects of inhaled nitric oxide to placebo on ventilatory efficiency (VE/VCO2), and IND at rest and during a standard cardiopulmonary exercise test (CPET). Twenty patients with diagnosed IPF with mild (or absent) mechanical restriction and 20 healthy age- and sex-matched controls will be recruited from a database of volunteers and from the Interstitial Lung Disease and Respirology clinics at Hotel Dieu Hospital. Participants with cardiovascular, or any other condition that contributes to dyspnea or abnormal cardiopulmonary responses to exercise will be excluded. After giving written informed consent, all participants will complete 7 visits, conducted 2 to 7 days apart. Visit 1 (screening): medical history, pulmonary function testing and a symptom limited incremental CPET. Visit 2: Standard CT examination conducted at KGH Imaging. Visit 3: assessment of resting chemoreceptor sensitivity, followed by a symptom limited incremental CPET to determine peak work rate (Wmax). Visits 4 \& 5 (run-in): familiarization to standardized constant work rate (CWR) CPET to symptom limitation at 75% Wmax. Visits 6 \& 7 (Randomized \& Blinded): CWR CPET to symptom limitation while breathing a gas mixture with either 1) 40 ppm iNO or 2) placebo \[medical grade normoxic gas, 21% oxygen\]. The proposed work has the potential to provide important physiological insights into the underlying mechanisms of heightened dyspnea, as well as examine therapeutic avenues to improve quality of life in patients with IPF.

Timeline

Start

2022-04-21

Primary completion

2024-12-30

Completion

2025-02-28

Publications

• Background Milne KM, Ibrahim-Masthan M, Scheeren RE, James MD, Phillips DB, Moran-Mendoza O, Ja N, O'Donnell DE. Inspiratory neural drive and dyspnea in interstitial lung disease: Effect of inhaled fentanyl. Respir Physiol Neurobiol. 2020 Nov;282:103511. doi: 10.1016/j.resp.2020.103511. Epub 2020 Aug 3.
• Background Faisal A, Alghamdi BJ, Ciavaglia CE, Elbehairy AF, Webb KA, Ora J, Neder JA, O'Donnell DE. Common Mechanisms of Dyspnea in Chronic Interstitial and Obstructive Lung Disorders. Am J Respir Crit Care Med. 2016 Feb 1;193(3):299-309. doi: 10.1164/rccm.201504-0841OC.
• Background Farina S, Bruno N, Agalbato C, Contini M, Cassandro R, Elia D, Harari S, Agostoni P. Physiological insights of exercise hyperventilation in arterial and chronic thromboembolic pulmonary hypertension. Int J Cardiol. 2018 May 15;259:178-182. doi: 10.1016/j.ijcard.2017.11.023.
• Background Kolb M, Raghu G, Wells AU, Behr J, Richeldi L, Schinzel B, Quaresma M, Stowasser S, Martinez FJ; INSTAGE Investigators. Nintedanib plus Sildenafil in Patients with Idiopathic Pulmonary Fibrosis. N Engl J Med. 2018 Nov 1;379(18):1722-1731. doi: 10.1056/NEJMoa1811737. Epub 2018 Sep 15.
• Background Nathan SD, Flaherty KR, Glassberg MK, Raghu G, Swigris J, Alvarez R, Ettinger N, Loyd J, Fernandes P, Gillies H, Kim B, Shah P, Lancaster L. A Randomized, Double-Blind, Placebo-Controlled Study of Pulsed, Inhaled Nitric Oxide in Subjects at Risk of Pulmonary Hypertension Associated With Pulmonary Fibrosis. Chest. 2020 Aug;158(2):637-645. doi: 10.1016/j.chest.2020.02.016. Epub 2020 Feb 21.
• Background Phillips DB, Brotto AR, Ross BA, Bryan TL, Wong EYL, Meah VL, Fuhr DP, van Diepen S, Stickland MK; Canadian Respiratory Research Network. Inhaled nitric oxide improves ventilatory efficiency and exercise capacity in patients with mild COPD: A randomized-control cross-over trial. J Physiol. 2021 Mar;599(5):1665-1683. doi: 10.1113/JP280913. Epub 2021 Jan 25.

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