The effects of respiratory muscle training in chronic kidney disease patients on haemodialysis and peritoneal dialysis: a review

Introduction
Recently, there has been a steady increase in the number of people diagnosed with chronic kidney disease (CKD). Reduction of respiratory muscle strength may be secondary to CKD. This article summarises available studies that evaluate the effect of respiratory muscle training in patients with CKD on haemodialysis and peritoneal dialysis.

Material and methods
The following databases were reviewed: Medline (PubMed), Scopus, Web of Science, Academic Search Complete, and Embase. For this analysis all published studies that investigated the effect of any form of respiratory muscle exercise on respiratory muscle strength, and the maximum inspiratory and expiratory pressure in adult patients chronically haemodialysed or on peritoneal dialysis, were included.

Results
Only four clinical trials that met inclusion criteria were identified (two randomised and controlled, one uncontrolled, and one non-randomised) involving a total of 108 patients. Threshold IMT (Inspiratory Muscle Trainer) and respiratory biofeedback methods were used for respiratory muscle training. Duration of training program tract was from six weeks to 10 weeks. The effects of respiratory muscle training were evaluated by PI_max, PE_max, FVC, PEF, and 6MWT.

Conclusions
Our review indicates that respiratory muscle training during haemodialysis may improve respiratory muscle strength and therefore improve exercise capacity in patients with chronic kidney disease. We did not find any data on the effects of respiratory muscle training on strength, pulmonary functional parameters, and exercise capacity in patients with chronic kidney disease on peritoneal dialysis.