Community-dwelling individuals with stroke, who have inspiratory muscle weakness, report greater dyspnea and worse quality of life

Is there a role of pulmonary rehabilitation in extrapulmonary diseases frequently encountered in the practice of physical medicine and rehabilitation?

There is a group of diseases such as low back pain, osteoporosis, fibromyalgia and obesity for which pulmonary rehabilitation can be applied. Although these diseases do not directly impact the lungs, respiratory dysfunction occurs through various mechanisms during the disease process and complicates the underlying primary disease. Respiratory dysfunction and spirometric abnormalities have been observed from the early stages of these diseases, even without obvious signs and symptoms. These patients should be carefully evaluated for pulmonary problems as a sedentary lifestyle may hide the presence of respiratory symptoms. Once pulmonary problems have been detected, pulmonary rehabilitation should be added to the routine treatment of the primary disease.

Stroke and breathing

Stroke remains a leading cause of neurologic disability with wide ranging effects, including a variety of respiratory abnormalities. Stroke may influence the central control of the respiratory drive and breathing pattern, airway protection and maintenance, and the respiratory mechanics of inspiration and expiration. In the acute phase of stroke, the central control of breathing is affected by changes in consciousness, cerebral edema, and direct damage to brainstem respiratory centers, resulting in abnormalities in respiratory pattern and loss of airway protection. Common acute complications related to respiratory dysfunction include dysphagia, aspiration, and pneumonia. Respiratory control centers are located in the brainstem, and brainstem stroke causes specific patterns of respiratory dysfunction. Depending on the exact location and extent of stroke, respiratory failure may occur. While major respiratory abnormalities often improve over time, sleep-disordered breathing remains common in the subacute and chronic phases and worsens outcomes. Respiratory mechanics are impaired in hemiplegic or hemiparetic stroke, contributing to worse cardiopulmonary health in stroke survivors. Interventions to address the respiratory complications are under researched, and further investigation in this area is critical to improving outcomes among stroke survivors.

"More air-better performance-faster recovery": study protocol for randomised controlled trial of the effect of post-stroke inspiratory muscle training for adults

BACKGROUND

Stroke results in varying physical, cognitive, emotional and/or social disabilities in the short and long term alike. Motor impairments are important, persistent consequences of stroke and include, among others, decreased respiratory muscle function, decreased ability to expand the thorax and postural dysfunction. These deficits affect the patient's ability to perform daily activities, produce fatigue and reduce endurance and quality of life. Inspiratory muscle training (IMT) aims to improve the strength and endurance of the diaphragm and the external intercostal muscles. The objectives of this study are to investigate the effect of 3 weeks of IMT on (i) maximal inspiratory pressure (MIP) in adults having suffered a stroke, as well as (ii) functional activities and expiratory measurements.

METHODS/DESIGN

This is a randomised controlled trial (RCT) comparing IMT with conventional neurorehabilitation (usual practice). The trial will include 80 patients with reduced MIP hospitalised at a specialised neurorehabilitation hospital in Denmark. The intervention group will receive IMT sessions, exercising at 30% of MIP. Patients in the intervention group will perform two daily sessions (one session of IMT with Threshold IMT consisting of two times 15 inspirations at normal breathing rhythm (5-10 min)), 7 days a week for 3 weeks. Training can be with or without physiotherapist supervision.

STUDY OUTCOMES

MIP assessed by the Power Breath, Functional Independence Measurement, The 6-min walk test, the Fatigue Severity Scale and average voice volume. Expiratory function will be assessed using spirometry. All assessments will be conducted at baseline and 3 weeks (at termination of the intervention) and 3 months after the intervention has concluded.

DISCUSSION

IMT is a promising and partly self-managed tool for rehabilitation to improve respiratory function. The introduction of IMT in combination with traditional physical therapy may enhance faster recovery after stroke and may at the same time demand little personnel resources to increase training intensity. This trial will provide further evidence of IMT to clinicians, patients and health managers. Hereby, this study accepts the call for further research.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04686019 . Registered on 28 December 2020.