The haemodynamic and metabolic effects of hypertonic-glucose and amino-acid-based peritoneal dialysis fluids

Background. Continuous ambulatory peritoneal dialysis (CAPD) may exert significant effects on systemic haemodynamics. We have previously demonstrated that hypertonic glucose solutions are associated with higher blood pressure (BP) due to a rise in stroke volume (SV) and cardiac output (CO). However, the mechanisms underlying these changes have not been established. Methods. Ten non-diabetic CAPD patients entered a randomized crossover study (eight completed) to compare conventional glucose-based fluid, biocompatible pH-neutral glucose-based fluid and 1.1% amino acid solution (lactate-buffered but completely free of glucose degradation products). BP and haemodynamic variables were measured using continuous arterial pulse wave analysis, and serial plasma glucose and insulin concentrations were collected. Left ventricular (LV) diameters were measured at the start and end of each dwell period using M-mode echocardiography. Results. BP was similar during 1.36% glucose and 1.1% amino acid dwells, but was significantly higher during 3.86% glucose dwells with both conventional and biocompatible fluids (P < 0.001). This was associated with a significantly higher SV and CO (P < 0.001), although the haemodynamic response differed between conventional and biocompatible 3.86% solutions. Plasma glucose and insulin levels did not differ from baseline during 1.36% and amino acid dwells, but increased significantly during 3.86% glucose dwells. Despite a significantly higher ultrafiltration volume with 3.86% glucose, LV diameters were similar throughout. Conclusions. In conclusion, we have confirmed our previous findings demonstrating higher BP and adverse haemodynamics during 3.86% glucose dwells. These changes are associated with hyperglycaemia and hyperinsulinaemia, but are not related to differences in cardiac filling.