Bedrest alters respiratory muscle strength in patients immobilized due to fractured femurs

Abstract

Bedrest produces decrements in the functioning of all physiological systems. Physiotherapists treat patients who are managed with Thomas splints following fractured femurs. The patients are generally compartmentally treated as orthopaedic patients. No attention is paid to the status of the respiratory system which can be the cause of morbidity in these patients. Since the ventilatory muscles play a major role in breathing and coughing the purpose of the present study was to determine the effect of a limited period of bedrest on the strength of the inspiratory and expiratory muscles.
A sample of convenience consisting of 15 African male patients immobilized by Thomas’ Splint for fractured mid-shaft femurs participated in the study by voluntary consent. All patients had been confined to bed for at least 3 weeks. Maximal inspiratory pressures (PiMAX) and Maximal expiratory pressures (PeMAX) were recorded using a Boehringer Force Meter at functional residual capacity in the semi-recumbent position. The data were normalized and analyzed using the student t-test at the 0.05% level.
The results showed a significant reduction in both PiMAX and PeMAX compared to age predicted normal values. The decrease in PeMAX was greater than that of PiMAX.
We conclude that respiratory muscle strength decays with bedrest.