Avaliação das pressões respiratorias maximas em pacientes renais cronicos submetidos a hemodialise

Abstract

BACKGROUND AND OBJECTIVES: Maximal inspiratory and expiratory pressures (PImax e PEmax) are used to evaluate the integrity of respiratory muscles by measuring their strength. The effects of hemodialysis on these variables in chronic renal failure (CRF) patients are not yet well established in the literature. The objective of this study was to evaluate the influence of hemodialysis on PImax and PEmax values. METHODS: A prospective, transversal study was done in a convenience sample of 35 CRF patients (26 men and 9 women), aged between 21 and 81 years, at the Nephrology Division of the Alzira Vellano University Hospital of Alfenas/MG/Brazil. The patients had their PImax andPEmax taken in the seated position (at 90°) by using a digital manovacuometer (MVD 300 ® ) attached to a notebook for reading and recording data obtained before and after the hemodialysis session. RESULTS: PImax and PEmax were found to be lower than those predicted at any moment (pre-and post-hemodialysis) (p<0.0001). By comparing the values obtained pre-hemodialysis with those observed post-hemodialysis, PImax showed a slight improvement (p=0.0420), particularly in those patients with pre-hemodialysis values lower than 60 cmH 2 O (Wilcoxon; p=0.0480). PEmax values post-hemodialysis were not different from those observed pre-hemodialysis (p=0.4987). CONCLUSION: CRF patients have serious impairment of their respiratory muscle function, and only one isolated hemodialysis session was not able to significantly improve their maximal respiratory pressures, except for a light improvement of inspiratory strength observed in those who had presented a PImax lower than 60 cmH 2 O before the procedure.