Magnesium free dialysis for uraemic pruritus.

Abstract

potential for growth, presumably as a result of metabolic disturbances during the pregnancy, and may therefore be termed "macrosomic."Acker et al' reported that the incidence of shoulder dystocia in the deliveries of diabetic mothers was 50%, 23%, and 9% for infants weighing :4500 g, 4000-4499 g, and 3500-3999 g, respectively, compared with 23%, 10%, and 2% for deliveries of non-diabetic mothers. Thus many more infants of diabetic mothers are too large for their maternal pelvis, even when their birthweight is apparently normal.Control of diabetes in pregnancy should not be described as "good" or "bad" as it forms a continuous range and thus would not be expected to have an all or nothing effect on promoting fetal growth. A substantial percentage of infants of diabetic mothers with birth weights within the normal range will be affected by the metabolic disturbances in the uterus caused by diabetes. In a review of 225 infants of diabetic mothers Lemons et al reported that neonatal hypoglycaemia occurred not only in 36 (47%) of the macrosomic infants, but also in 31 (21%) of the infants with birth weights that were not large for gestational age.4 The extent to which an infant will be affected by maternal diabetes, as measured by birth weight or neonatal hypoglycaemia, will vary, explaining why "good" control in the conventional sense may result in a big baby who becomes hypoglycaemic whereas "bad" control may result in a small baby who does not.Our results suggest that all infants of diabetic mothers, irrespective of birth weight, are growth promoted to some degree by their mothers' disease, and thus every infant should be considered to be at risk from the biochemical and mechanical consequences of macrosomia. From an initial study of renal itch in patients undergoing long term haemodialysis 20 patients were identified as being severely affected by uraemic pruritus (itch score more than 200 a week).3 Three patients were excluded as they were on non-standard dialysis fluid, and the others continued to fulfil the previous entry requirements3 and were not taking drugs containing magnesium. The 17 patients included in the trial (one woman) were aged 25-69; had been undergoing maintenance haemodialysis for 4-79 months; received 9-14 hours of dialysis a week on Dylade D2 or Gambro AKIO machines, with Travenol ST12/11 dialysis membrane, and remained on the same machines and dialyser throughout the trial.The patients were randomly allocated into two groups by a double blind technique. Group 1 (seven patients) remained on the standard dialysis fluid (McCarthy's QE136) with a magnesium concentration of 0 85 mmol/l, while group 2 was changed to one free of magnesium (McCarthy's S597). In all other respects the composition of the dialysis fluid was identical. After two weeks the dialysis fluids of the two groups were swapped for a further fortnight. The serum magnesium concentration was measured before and after dialysis at entry and weekly throughout the trial. Serum parathyroid hormone concentration was measured at entry and...

Recent Advances in Treatment for Uremic Pruritus

“…In contrast, Carmichael et al [29] failed to demonstrate a beneficial effect of reduction in magnesium on pruritus. In their trial, although they showed that a magnesium-free dialysis fluid corrected hypermagnesaemia, it failed to improve renal itch.…”

What is the Role of Sensitization in Uremic Pruritus?

“…Hypervitaminosis A [6], hypermagne semia [5], and HPTH [4] have been indicated as possible responsible factors. All uremic patients have hypervitam inosis A, but not all of them suffer from pruritus.…”

“…Pruritus can be exclusively intradialytic, but more often it is continuous with intradialytic exacerbation. Several etiopathogenetic hypotheses have been formu lated: hyperparathyroidism (HPTH) [4], hypermagne semia [5] and hypervitaminosis A [6], Studies on the biocompatibility of the components of dialytic circuits have suggested their possible role in the pathogenesis of dialytic intolerance phenomena [7][8][9][10][11]. Ethylene oxide (EO) in particular has been regarded as a major factor [12].…”

Uremic Pruritus – An Update

“…An increased skin divalent ion concentration may lead to microprecipitation of calcium or magnesium phosphate, which may be the cause of pruritus. In spite of these facts, only a few studies showed a significant correlation between serum or skin divalent ion content and the presence of pruritus [7,22,43,47]. Magnesium itself may be involved in the modulation of nerve conduction and release of histamine from mast cells [44].…”