Mass transfer of calcium across the peritoneum at three different peritoneal dialysis fluid Ca2+ and glucose concentrations
✍ Scribed by Simonsen, Ole; Venturoli, Daniele; Wieslander, Anders; Carlsson, Ola; Rippe, Bengt
- Book ID
- 104474731
- Publisher
- Nature Publishing Group
- Year
- 2003
- Tongue
- English
- Weight
- 176 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0085-2538
No coin nor oath required. For personal study only.
✦ Synopsis
Background:
In peritoneal dialysis, the rate of ultrafiltration has been predicted to be a major determinant of peritoneal calcium (ca2+) removal. hence, dialysis fluid glucose concentration should be an important factor governing the transperitoneal ca2+ balance. the aim of this study was to test the effect of various dialysate glucose levels and selected dialysate ca2+ levels on ca2+ removal in peritoneal dialysis patients.
Methods:
Patients (n = 8) received, during a 7-week period, 2 l of lactate (30 mmol/l)/bicarbonate (10 mmol/l)-buffered peritoneal dialysis solutions containing either 1.5% glucose and 1.0 mmol/l ca2+ or 2.5% glucose and 1.6 mmol/l ca2+, or 4% glucose and 2.5 mmol/l ca2+, respectively, provided in a three-compartment bag (trio system). patients underwent standardized (4-hour) dwells, one for each of the three dialysates to assess permeability-surface area product (ps) or mass transfer area coefficients (mtac) for ionized and "freely diffusible" ca2+, lactate, glucose, bicarbonate, phosphate, creatinine, and urea.
Results:
There was a clear-cut dependence of peritoneal ca2+ removal on the rate of ultrafiltration. for large peritoneal to dialysate ca2+ gradients (2.5 mmol/l ca2+ in 4% glucose) a close fit of measured to simulated data was predicted by the three-pore model using nonelectrolyte equations. for low transperitoneal ca2+ concentration gradients, however, directly measured ca2+ data agreed with the simulated ones only when the peritoneal ca2+ ps was set lower than predicted from pore theory (6 ml/min).
Conclusion:
There was a marked ultrafiltration dependence of transperitoneal ca2+ transport. nonelectrolyte equations could be used to simulate peritoneal ion (ca2+) transport provided that the transperitoneal ion concentration gradients were large. based on our data 1.38 mmol/l ca2+ in the dialysis fluid would have created zero net ca2+ gain during a 4-hour dwell for 1.5% glucose, whereas 1.7 and 2.2 mmol/l ca2+ would have been needed to produce zero ca2+ gain for 2.5% glucose and 3.9% glucose, respectively.