Does Respiratory Muscle Training Improve Cough Flow in Acute Stroke? Pilot Randomized Controlled Trial

Abstract

The study was a single-blind randomized controlled trial with 3 study groups; reporting followed Consolidated Standards of Reporting Trials (CONSORT) guidelines.9 Subjects were allocated using aBackground and Purpose-Cough protects the lungs from aspiration. We investigated whether respiratory muscle training may improve respiratory muscle and cough function, and potentially reduce pneumonia risk in acute stroke. Methods-We conducted a single-blind randomized placebo-controlled trial in 82 patients with stroke (mean age, 64±14 years; 49 men) within 2 weeks of stroke onset. Participants were masked to treatment allocation and randomized to 4 weeks of daily expiratory (n=27), inspiratory (n=26), or sham training (n=25), using threshold resistance devices. Primary outcome was the change in peak expiratory cough flow of maximal voluntary cough. Intention-to-treat analyses were conducted using ANCOVA, adjusting for baseline prognostic covariates. Results-There were significant improvements in the mean maximal inspiratory (14 cmH 2 O; P<0.0001) and expiratory (15 cmH 2 O; P<0.0001) mouth pressure and peak expiratory cough flow of voluntary cough (74 L/min; P=0.0002) between baseline and 28 days in all groups. Peak expiratory cough flow of capsaicin-induced reflex cough was unchanged. There were no between-group differences that could be attributed to respiratory muscle training. There were also no differences in the 90-day incidence of pneumonia between the groups (P=0.65). Conclusions-Respiratory muscle function and cough flow improve with time after acute stroke. Additional inspiratory or expiratory respiratory muscle training does not augment or expedite this improvement. Clinical Trial Registration-URL: http://www.controlled-trials.com. Unique identifier: ISRCTN40298220.

Cough strength and expiratory force in aspirating and nonaspirating postradiation head and neck cancer survivors

“…Perhaps most notable in reference to the relationship of PCF and airway protection is the significant association between voluntary PCF and pneumonia, previously reported in acute stroke populations with regression models estimating approximately 2% reduction in pneumonia risk for every 10 L/minute increase in PCF . Maximum expiratory pressure and PCF are directly related .…”

“…For instance, PCF is depressed in stroke patients with dysphagia relative to matched healthy controls, as well as in PD participants with penetration or aspiration on videofluoroscopy relative to PD participants with normal airway closure during swallow. 21,22 Perhaps most notable in reference to the relationship of PCF and airway protection is the significant association between voluntary PCF and pneumonia, previously reported in acute stroke populations with regression models estimating approximately 2% reduction in pneumonia risk for every 10 L/minute increase in PCF. 22 Maximum expiratory pressure and PCF are directly related.…”

“…Peak cough flow is depressed in populations with dysphagia related to neurogenic pathology. For instance, PCF is depressed in stroke patients with dysphagia relative to matched healthy controls, as well as in PD participants with penetration or aspiration on videofluoroscopy relative to PD participants with normal airway closure during swallow …”

Aspiration pneumonia induces muscle atrophy in the respiratory, skeletal, and swallowing systems

“…The number of deaths caused by pneumonia is increasing due to ageing of the population and a new target for treating aspiration pneumonia is needed. Cough is the most potent protective mechanism against aspiration and requires the activation of the inspiratory and expiratory respiratory muscles . The diaphragm is central among the respiratory muscles .…”

“…Cough is the most potent protective mechanism against aspiration and requires the activation of the inspiratory and expiratory respiratory muscles. 9 The diaphragm is central among the respiratory muscles. 10 Dysfunction of swallowing physiology is one of the mechanisms that causes aspiration pneumonia.…”