Dialysis-induced changes in muscle strength.

Little is known about the acute effects of hemodialysis on muscle strength. Rapid changes in hemodynamic and biochemical parameters are known to occur during dialysis and may alter muscle performance. Ten patients maintained on chronic hemodialysis had measurements of quadriceps muscle and handgrip strength performed before and after dialysis. In seven of these patients maximum static inspiratory and expiratory pressures (PI max and PE max respectively) were similarly determined. Quadriceps muscle strength improved in 6 patients, decreased in 3 and remained unchanged in 1. Handgrip strength increased in 5 patients, decreased in 3, and remained unchanged in 1. PI max decreased in 6 patients and increased in 1, and PE max decreased in 4 patients and increased in 3. No significant correlation was found between the changes in strength of the tested muscle groups and the serum concentrations of sodium, potassium, calcium, phosphorus, urea nitrogen, and creatinine, changes in blood pressure of fluid balance. The dialysis-induced changes in biochemical parameters may exert opposing effects on neuromuscular performance. This may explain the diversity of the results obtained in this study.