Peritoneal Clearance and Peritoneal Transfer of Oxalic Acid, Vitamin C, and Vitamin B₆ During Continuous Ambulatory Peritoneal Dialysis

Abstract

The peritoneal clearance and peritoneal transfer of oxalic acid, vitamin C, and vitamin B6 in 32 patients during continuous ambulatory peritoneal dialysis (CAPD) using peritoneal dialysis solutions containing 1.5% or 2.5% glucose were examined. The plasma level of oxalic acid was significantly elevated in all patients, plasma vitamin C was in the normal range or in the upper margin of the normal range, and plasma vitamin B6 was in the normal range. The peritoneal clearance of oxalic acid was significantly lower, and the peritoneal clearance of vitamin B6 was the lowest in comparison to the peritoneal clearance of urea. With the exception of vitamin B6, the peritoneal clearance and peritoneal transfer of the examined parameters increased using the dialysis solution containing 2.5% glucose. We found direct relationships between the plasma levels of oxalic acid and creatinine as well as plasma vitamin C and between the peritoneal transfer of oxalic acid and the peritoneal transfer of vitamin C as well as vitamin B6. The significant hyperoxalemia of our patients was found to persist despite the relatively high peritoneal transfer of oxalic acid during CAPD. These results suggest that CAPD is not a method effective enough for permanent reduction of the plasma levels of oxalic acid.

High prevalence of ascorbate deficiency in an Australian peritoneal dialysis population

“…Although this is accumulation is a theoretical concern, the harm associated with untreated ascorbate deficiency is well accepted. We prescribed a supplement containing 120 mg ascorbate as it was similar to the dose shown not to raise blood oxalate levels in a group of haemodialysis and PD patients, 18 and approximated the estimated daily loss for PD patients with normal levels 11 . Aside from two patients where non‐adherence was suspected, a daily supplement of 120 mg appeared sufficient to achieve adequate ascorbate levels.…”

“…In diabetic renal disease, urinary ascorbate losses rise with both increasing proteinuria and increasing serum creatinine 10 . Removal of ascorbate by peritoneal dialysis (PD) is proportional to the peritoneal creatinine clearance, with losses estimated at 0.095 mL/s for a 2.5% dextrose exchange 11 . In PD patients low ascorbate levels have been associated with low serum albumin 12 .…”

Ethambutol and isoniazid induced severe neurotoxicity in a patient undergoing continuous ambulatory peritoneal dialysis

“…Siskind et al 8 recommended 100 mg/day pyridoxine supplementation as a routine prophylaxis against INH toxicity in patients undergoing haemodialysis. The clearance of pyridoxine during peritoneal dialysis is very low, being only 8.8% of urea clearance 34. In the present case, the intravenous supplementation of pyridoxine (1 mg/kg/day) was sufficient to reverse INH-induced peripheral neuropathy, which was likely due to slower pyridoxine removal during peritoneal dialysis than during haemodialysis.…”

Scurvy in a hemodialysis patient. Rare or ignored?

“…Many of the symptoms of scurvy such as anemia, weakness and gingival bleeding are often seen in hronic kidney disease (CKD) patients as well, which creates a confounding picture . In addition to low dietary intake, dialysis itself also contributes to deficiency . Removal of vitamin C, a water‐soluble non‐protein‐bound small molecule, has been estimated at mean 66 mg per HD session and 29 mg per (peritoneal dialysis) PD exchange .…”

“…1 In addition to low dietary intake, dialysis itself also contributes to deficiency. [4][5][6][7] Removal of vitamin C, a watersoluble non-protein-bound small molecule, has been estimated at mean 66 mg per HD session 6 and 29 mg per (peritoneal dialysis) PD exchange. 7 Interestingly, in PD, transport status was not predictive of vitamin C levels.…”