Acute effects of photobiomodulation on respiratory variables and functional capacity in patients with chronic obstructive pulmonary disease

Abstract

Chronic obstructive pulmonary disease (COPD) is considered one of the main causes of mortality and overall disability worldwide. Among several abnormalities present in patients with COPD, the musculoskeletal dysfunction must be highlighted, since it impairs the functional capacity, health and quality of life of these patients. Recently, photobiomodulation has gained attention due to its effectiveness in improving muscular performance in athletes and some diseases. However, the use of photobiomodulation aiming to improve muscular performance in individuals with respiratory diseases is incipient in the literature. Objective: to evaluate the acute effects of photobiomodulation on lung function, respiratory muscle strength, thoracoabdominal mobility and functional capacity in individuals with COPD. Material and methods: A randomized, controlled, double-blind, crossover trial will be conducted. Twenty subjects with a diagnosis of COPD will participate in the study. All participants will be randomized and allocated to receive two photobiomodulation sessions, one week apart: 1) an effective photobiomodulation session will be applied at the main respiratory muscles by means of a cluster with 69 light-emitting diodes (LEDs), containing 35 red (630 ± 10 nm; 10 mW; 0,2 cm2) and 34 near-infrared (830 ± 20 nm; 10 mW; 0,2 cm2) LEDs; and 2) a sham photobiomodulation session, in which the same procedures of the effective session will be followed, but the equipment will not emit light. All participants will be evaluated in three moments: 1) Pre-intervention, 2) 1 hour after the intervention and 3) 24 hours after the intervention. All volunteers will be submitted to the assessment of pulmonary function through spirometry, maximal respiratory pressures through manovacuometry, and thoracoabdominal mobility by means of cirtometry at the axillary, xiphoid and abdominal levels. At baseline and 24 hours after the intervention, functional capacity will also be assessed by the 6-minute walk test. For all the analysis the significance level will be set at 5%. (AU)