title: Efficacy of non-invasive ventilation as a rescue therapy for relieving dyspnea in patients with stable severe COPD.
abstract: Exertional Dyspnea is a troublesome symptom in chronic obstructive pulmonary disease (COPD) even after optimal therapy, which is a physiological and perceptional burden to limit their activities. Non-invasive ventilation (NIV) might provide rescue therapy for this population to relieve exertional dyspnea. This was a randomized crossover study in 18 patients with stable severe COPD. Exertional dyspnea was induced with maximal symptom-limited incremental cycle exercise. Then the patients would randomly receive oxygen or NIV plus oxygen therapy. Patients were crossed to another therapy in the second day. During the whole process, breathing pattern were monitored continuously until complete recovery. At every 30s interval, inspiratory capacity (IC) and Borg scale were assessed. Changes were compared between two interventions. Compared with oxygen therapy, NIV plus oxygen therapy resulted in increase of tidal volume and minute ventilation, decrease in dyspnea intensity at isotime (reduction of 1.0 ± 2.0 Borg units, p < 0.05) and a tendency but not statistically significant shortening in total dyspnea recovery time (326.2 ± 132.0s vs 356.5 ± 156.9s, p = 0.225). These improvements were negatively correlated with baseline FEV1(r = -0.617, p < 0.01). Subjects were divided into responders (n = 9) with dyspnea recovery time shortening > 30s or non-responders. Responder subgroup had significantly poorer pulmonary function in FEV1, FEV1%, IC than non-responder subgroup, indicating that NIV is effective as rescue therapy for exertional dyspnea in stable COPD with poorer pulmonary function. NIV as rescue therapy could help relieve dyspnea after exercise in patients with stable severe COPD with a poor pulmonary function.
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China. Electronic address: ouyongercandy@126.com.
authors.forename: Yong-Er
authors.initials: YE
authors.lastname: Ou
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China. Electronic address: doctorlin3@126.com.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China. Electronic address: 781816296@qq.com.
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China. Electronic address: luoqunx@163.com.
authors.forename: Qun
authors.initials: Q
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China. Electronic address: rcchengird@163.com.
authors.forename: Rong-Chang
authors.initials: RC
authors.lastname: Chen
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D004417:Dyspnea / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000379:methods*; D010102:Oxygen Inhalation Therapy / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D015656:Respiratory Mechanics / Q000502:physiology; D016896:Treatment Outcome
keywords: Chronic obstructive pulmonary disease; Exertional dyspnea; Non-invasive ventilation; Rescue therapy