Comparison of 50% dextrose water, 25% mannitol, and 23.5% saline for the treatment of hemodialysis-associated muscle cramps

Hypertonic solutions of dextrose (D), mannitol (M), and saline (S) are effective treatments for hemodialysis-associated muscle cramps, but have not been directly compared to one another. Concern exists that postdialysis retention of M and S may lead to increased thirst, interdialytic weight pain (IDWG), and elevated blood pressure. The authors performed a prospective, randomized, double-blind crossover study to compare the efficacy of D, M, and S in 24 chronic hemodialysis patients. Cramps were treated with 50 ml (126 mOsm) D, 100 ml (138 mOsm) M, and 16 ml (126 mOsm) S. All patients were assigned to each regimen for a 2 week period. For the entire patient group (n = 24), mean cramp duration (+/- SD) was less for M compared to D (9 +/- 5 vs 13 +/- 12 min, p less than 0.05), but not to S (10 +/- 6, p = NS) although not every patient had a cramp episode during each 2 week period of study. In a subgroup of 11 patients with a mean of 3.7 (range 1-6) cramps during each 2 week period, the efficacy of D, M, and S was similar. In both patient groups, IDWG, blood pressure control, and the frequency of adverse effects was similar with the use of all three agents. Mild postdialysis hyperglycemia and hypernatremia during D and S, respectively, were the only significant laboratory abnormalities. The authors conclude: 1) the safety and efficacy of D, M, and S are equivalent, and 2) the nonmetabolized osmotic agents M and S do not lead to increased IDWG or decreased blood pressure control.