Effect of expiratory muscle training on peak cough flow in children and adolescents with cystic fibrosis: A randomized controlled trial

Abstract

Background Cough is an important defense and airway clearance mechanism for removing thick and viscous secretions in cystic fibrosis (CF). The primary aim of this study was to investigate the effect of expiratory muscle training (EMT) on peak cough flow (PCF) and secondly on respiratory muscle functions, functional exercise capacity, and quality of life (QoL) in CF. Methods Thirty patients were randomized as training and sham groups. Both groups were trained with the EMT protocol, which involved twice per day for at least 5 days per week for 6 weeks. The training intensity in the training group was 30% of the maximal expiratory pressure (MEP). In the sham group, it remained at the lowest pressure (5 cmH2O). The primary outcome was PCF. The secondary outcomes were MEP, maximal inspiratory pressure (MIP), spirometric measures, six‐minute walking distance (6MWD), and QoL (Cystic Fibrosis Questionnaire‐Revised). Results Twenty‐eight patients completed the study. Changes in PCF (p = .041) and MEP (p = .003) were higher in the training group than the sham group. Also, treatment burden (p = .008), digestive symptoms (p = .019), and vitality (p = .042) in QoL were more improved in the training group. MIP (p = .028) and 6MWD (p = .035) changed significantly only in the training group. Spirometric measurements did not change (p > .05). Conclusions The results of the study show that EMT could improve PCF, MEP, treatment burden, digestive symptoms, and vitality domains of QoL in patients with CF. Moreover, MIP and functional exercise capacity improved in the training group with EMT.

Effectiveness of Physical Exercise Interventions on Pulmonary Function and Physical Fitness in Children and Adults with Cystic Fibrosis: A Systematic Review with Meta-Analysis

“…Pulmonary, cardiorespiratory, and strength outcomes were analyzed in seven studies [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ] with a total of 219 children aged 11–14 years (51% male), and in five studies [ 31 , 32 , 33 , 34 , 35 ] with a total of 180 adults aged 22–57 years (45% male).…”

“…Interventions in children with CF were conducted for 2 to 12 months, and the modes of exercise were resistance training (four studies [ 25 , 26 , 27 , 30 ]), resistance training + neuromuscular electrical stimulation (one study [ 27 ]), and respiratory muscles training (three studies [ 24 , 28 , 29 ]). The participants trained for 60–210 min per week at a low to moderate intensity, divided into 3 to 5 sessions per week.…”

“…The risk of bias analysis revealed that seven studies (58%) [ 24 , 25 , 26 , 27 , 32 , 34 , 35 ] presented low risk, and five studies (42%) [ 28 , 29 , 30 , 31 , 33 ] were classified as presenting some concerns. The most common biases were: (i) “bias arising from the randomization process” where five studies (42%) [ 29 , 31 , 32 , 33 , 34 ] were classified as “some concerns”, mainly because the process was not sufficiently described; (ii) and “bias in selection of the reported result”, where five studies (42%) [ 28 , 29 , 30 , 31 , 33 ] were classified as “some concerns” ( Figure 2 and Figure 3 ).…”

“…In children with CF, four studies [ 24 , 28 , 29 , 30 ] analyzed the FEV1 and the forced vital capacity, without changes. Meta-analysis of this outcome was not performed because of missing standard deviations.…”

“…Meta-analysis of this outcome was not performed because of missing standard deviations. One study [ 28 ] observed a significant increase in MIP (+37.63 ± 8.21 cm H 2 O; p < 0.001), while another study [ 24 ] observed no changes. Concerning MEP, one study [ 24 ] observed a significant increase in MEP (+12.42 ± 9.52 cm H 2 O; p = 0.003), while another study [ 28 ] observed no changes.…”