Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review.

QUESTION

Does inspiratory muscle training improve respiratory muscle strength, functional capacity, lung function and quality of life of patients with chronic kidney disease? Does inspiratory muscle training improve these outcomes more than breathing exercises?

DESIGN

Systematic review and meta-analysis of randomised trials.

PARTICIPANTS

People with chronic kidney disease undergoing dialysis treatment.

OUTCOME MEASURES

The primary outcomes were: maximal inspiratory pressure, maximal expiratory pressure, and distance covered on the 6-minute walk test. The secondary outcomes were: forced vital capacity, forced expiratory volume in the first second (FEV), and quality of life.

RESULTS

The search identified four eligible studies. The sample consisted of 110 participants. The inspiratory muscle training used a Threshold or PowerBreathe device, with a load ranging from 30 to 60% of the maximal inspiratory pressure and lasting from 6 weeks to 6 months. The studies showed moderate to high risk of bias, and the quality of the evidence was rated low or very low, due to the studies' methodological limitations. The meta-analysis showed that inspiratory muscle training significantly improved maximal inspiratory pressure (MD 23 cmHO, 95% CI 16 to 29) and the 6-minute walk test distance (MD 80m, 95% CI 41 to 119) when compared with controls. Significant benefits in lung function and quality of life were also identified. When compared to breathing exercises, significant benefits were identified in maximal expiratory pressure (MD 6 cmHO, 95% CI 2 to 10) and FEV (MD 0.24litres 95% CI 0.14 to 0.34), but not maximal inspiratory pressure or forced vital capacity.

CONCLUSION

In patients with chronic renal failure on dialysis, inspiratory muscle training with a fixed load significantly improves respiratory muscle strength, functional capacity, lung function and quality of life. The evidence for these benefits may be influenced by some sources of bias.

REGISTRATION

PROSPERO (CRD 42015029986). [de Medeiros AIC, Fuzari HKB, Rattesa C, Brandão DC, de Melo Marinho PÉ (2017) Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review. Journal of Physiotherapy 63: 76-83].