Management of hypophosphatemia in nocturnal hemodialysis with phosphate-containing enema: A technical study

Abstract

Hypophosphatemia is observed in patients undergoing nocturnal hemodialysis. Phosphate is commonly added to the dialysate acid bath, but systematic evaluation of the safety and reliability of this strategy is lacking. The objectives of this study were 4-fold. First, we determined whether predictable final dialysate phosphate concentrations could be achieved by adding varying amounts of Fleet® enema. Second, we assessed the stability of calcium (Ca) and phosphate dialysate levels under simulated nocturnal hemodialysis conditions. Third, we assessed for Ca-phosphate precipitate. Finally, we evaluated whether dialysate containing Fleet® enema met the current sterility standards. We added serial aliquots of enema to 4.5 L of dialysate acid concentrate and proportioned the solution on Gambro and Althin/Baxter dialysis machines for up to 8 hours. We measured dialysate phosphate, Ca, pH, and bicarbonate concentrations at baseline, and after simulated dialysis at 4 and 8 hours. We evaluated for precipitation visually and by assessing optical density at 620 nm. We used inoculation of agar to detect bacteria and Pyrotell reaction for endotoxin. For every 30 mL of Fleet® (1.38 mmol/mL of phosphate) enema added, the dialysate phosphate concentration increased by 0.2 mmol/L. There were no significant changes in dialysate phosphate, Ca, pH, and bicarbonate concentrations over 8 hours. No precipitate was observed in the dialysate by optical density measures at 620 nm for additions of up to 90 mL of enema. Bacterial and endotoxin testing met sterility standards. The addition of Fleet® enema to dialysate increases phosphate concentration in a predictable manner, and no safety problems were observed in our in vitro studies.

Successful Detection and Removal of a Functional Parathyroid Adenoma in a Pony Using Technetium Tc 99m Sestamibi Scintigraphy

“…Intravenous supplementation was initiated at 0.04 mmol/kg/h phosphorus (0.03 mL/kg/h Fleet enema; [phosphorus] = 1.38 mmol/mL of enema), 2 mg/kg/h magnesium as magnesium sulfate, and 20 mg/kg/h calcium as calcium gluconate. Fleet enema was considered safe for IV use based on prior publication describing its safe use for human dialysis 1. Oral supplementation was initiated at 18 mg/kg calcium (30 cc of calcium chloride gel8) PO q12h, 0.15 g/kg potassium as potassium phosphate (K 2 HPO 4 ) PO q12h and 0.05 g/kg magnesium as magnesium oxide (MgO) PO q12h.…”

Fractures and Osteomalacia in a Patient Treated With Frequent Home Hemodialysis

“…The present case illustrates the utility of bone biopsy in such patients in order to define the long-term consequences. The addition of Fleet® enema solution stably increases the dialysate phosphate concentration, without affecting the concentrations of other dialysate solutes 20 . Furthermore, no bacteria or endotoxin have been detected in samples of Fleet ® -enriched dialysate 20 .…”

“…The addition of Fleet® enema solution stably increases the dialysate phosphate concentration, without affecting the concentrations of other dialysate solutes 20 . Furthermore, no bacteria or endotoxin have been detected in samples of Fleet ® -enriched dialysate 20 . As such, this simple intervention may safely be able to maintain normophosphatemia in patients on extended-hours hemodialysis, and would be especially beneficial for patients with biopsy-proven osteomalacia.…”

Phosphate Enrichment of Dialysate for Use in Standard and Extended Haemodialysis

“…More recently, Su et al [25] used Fleet to achieve stable phosphate and calcium concentrations and pH in final dialysate for up to 8 h. In their study, the maximum dialysate phosphate concentration obtained was up to 0.6 mmol/l, achieved by adding 90 ml of Fleet to a 4.5-litre canister of acid dialysate concentrate proportioned differently with base concentrate and purified water (1:1.72:42.28). They found no change in the electrolyte composition and no crystal formation at the end of an 8-hour period.…”

“…Fleet® is a convenient source of phosphate as it is readily available, and has recently been shown to be safe for such use [25]. Fleet® volume and achieved phosphate concentrations showed a linear relationship with a simple regression equation that enabled to predict the Fleet® volume to be added to 6 litres of acid dialysate concentrate using a standard 1:34:1.83 proportioning ratio for a desired dialysate phosphate concentration.…”