Peritoneal dialysis: new developments and new problems

To ascertain the incidence of hyponatraemia, and the impact of an icodextrin-based dialysis solution regime on hyponatraemia, in diabetic and non-diabetic patients using peritoneal dialysis (PD).

Following severe hyponatraemia, resulting in neurological sequelae, in two diabetic patients who were on icodextrin-based PD for established renal failure, we reviewed the results of all our PD patients. Data was gathered retrospectively, from our database and case notes, on plasma sodium, haematocrit, dry weight estimation, plasma albumin and residual renal function. Patients using icodextrin-based solutions were compared with a random selection of patients using dextrose-based peritoneal solutions. We also compared diabetic patients on and off icodextrin with their non-diabetic counterparts using the same dialysis regime. The data were analysed using the paired Student's t-test.

Plasma sodium was significantly lower in all patients using icodextrin-based solutions compared with those patients on dextrose-based PD. Plasma sodium was also found to fall in all patients following the initiation of an icodextrin-based PD regime. The fall in plasma sodium was statistically significant in diabetic and non-diabetic patients, but only fell below the laboratory reference range in the diabetic patients.

Icodextrin-based PD is a risk factor for hyponatraemia and may produce clinically relevant symptoms if, as in our two cases, the hyponatraemia is compounded by other factors.