Title: Pilot studies to develop and evaluate a muscle strengthening programme to reduce the risk of aspiration and improve outcome in dysphagic stroke patients.
Funder: Department of Health (England)

Abstract: Background Dysphagia is common after stroke; its incidence ranges from 51-78% and is associated with a 2-20 fold increase in chest infections.[1] A number of strategies have been developed to prevent aspiration in stroke patients but are of limited efficacy.[2] Cough, an important defence mechanism against aspiration, is impaired in stroke patients and a weak cough is associated with increased chest infections in these patients.[3,4] Respiratory muscle training has been shown to improve muscle function and reduce pulmonary complications, is relatively simple and can be delivered by multidisciplinary staff in clinical settings.[5-7] However, there is little previous experience of these techniques in stroke patients and their feasibility, acceptability, safety and effectiveness remain unknown. Aims The aim of this research is to undertake a series of pilot studies to develop a programme of inspiratory or/and expiratory muscle training that will improve cough flow rates and reduce aspiration in dysphagic stroke patients. We will: 1) estimate the duration of muscle training required to strengthen respiratory muscle function; 2) assess acceptability and safety of this training in stroke patients who may be older, have multiple co-morbidities and be prone to fatigue; 3) evaluate the feasibility of delivering respiratory muscle training in acute NHS settings; and 4) measure the change in the patient endpoints of aspiration, cough flow rates, frequency of chest infection and dependence to estimate the sample size required for a larger Phase III trial. Plan of Investigation 60 ischaemic stroke patients with dysphagia aged between 50-80 years will be allocated to expiratory muscle, inspiratory muscle or sham training. Training will be individualised and escalating intensity will be given for 5 days/week for 4 weeks. Gains in respiratory muscle strength will be assessed against training intensity to determine the optimum dose. Safety and tolerance will be assessed by recording blood pressure, heart rate, fatigue, adverse events, number of sessions completed, reasons for non completion and ratio of included to screened subjects. Elements of staff training will be identified and the feasibility of delivering the intervention evaluated. Changes in patient outcome (aspiration, cough, chest infections, daily activities) will be measured at 4 and 12 weeks. Potential Impact Dysphagia is common in stroke and associated with an increase in the number of patients with aspiration pneumonia, poor nutrition, mortality, prolonged hospitalisation, and institutionalisation.[8,9] Dysphagia management strategies have shown limited effectiveness for improving patient outcomes. An alternative approach that focuses on the use of a muscle training regimen to rehabilitate respiratory function and cough is novel and can complement existing strategies. This study is the first step in determining whether respiratory muscle training is a worthwhile approach to pursue by providing estimates on its feasibility, acceptability, safety and magnitude of effect prior to undertaking large and expensive Phase III trials to assess effectiveness in accordance with the MRC framework.[10]


Research activity codes: 6.7 PHYSICAL
Health categories: STROKE