Optimizing haemodialysate composition

Abstract

Survival and quality of life of dialysis patients are strictly dependent on the quality of the haemodialysis (HD) treatment. In this respect, dialysate composition, including water purity, plays a crucial role. A major aim of HD is to normalize predialysis plasma electrolyte and mineral concentrations, while minimizing wide swings in the patient's intradialytic plasma concentrations. Adequate sodium (Na) and water removal is critical for preventing intra- and interdialytic hypotension and pulmonary edema. Avoiding both hyper- and hypokalaemia prevents life-threatening cardiac arrhythmias. Optimal calcium (Ca) and magnesium (Mg) dialysate concentrations may protect the cardiovascular system and the bones, preventing extraskeletal calcifications, severe secondary hyperparathyroidism and adynamic bone disease. Adequate bicarbonate concentration [HCO3−] maintains a stable pH in the body fluids for appropriate protein and membrane functioning and also protects the bones. An adequate dialysate glucose concentration prevents severe hyperglycaemia and life-threating hypoglycaemia, which can lead to severe cardiovascular complications and a worsening of diabetic comorbidities.

Optimizing dialysate potassium

“…Despite our best intentions, these conclusions are only a best guess, based on observational data and opinion. Of note however, similar conclusions were reached in several recent review articles on this topic …”

“…Of note however, similar conclusions were reached in several recent review articles on this topic. 1,12,23,24 It is a concern that after 50 years of chronic hemodialysis, there are so few randomized controlled clinical trials to inform decisions about potassium dialysate prescription, and about most other aspects of the HD prescription. The North American dialysis industry has evolved to the point where facilities, chains, networks, agencies and national organizations collect and share sufficient administrative and patient outcome data, such that it ought to be feasible to conduct pragmatic, facility based randomized controlled clinical trials to empirically test the ideas we put forth in this article, and many others.…”

“…A typical hemodialysis session removes 70–100 mmol, or 210–300 mmol/week . Most of the potassium removal during hemodialysis is diffusive, but 15% is via ultrafiltration . For a HD patient to maintain balance, additional gastrointestinal and possibly urinary clearance of potassium may be required.…”

Dialysate Calcium Concentration below 3.0 mEq/L Is Not Associated with Improved Outcomes in the Japanese Dialysis Outcomes and Practice Patterns Study

“…Several studies have shown that a lower D-Ca may increase the chance of sudden cardiac death, whereas a higher D-Ca may cause positive Ca balance leading to vascular calcification. Locatelli et al [21] reviewed the effect of potassium, bicarbonate, magnesium, calcium, and sodium. High D-Ca of 3.5 mEq/L was an independent contributor to PTH over-suppression and was associated with increased CVD death, as also reported by Merle et al [22] Similarly, Kim et al [4] found that high D-Ca of 3.5 mEq/L was associated with increased all-cause mortality in incident HD patients.…”

Low dialysate potassium concentration is associated with prolonged recovery time

“…There is ongoing controversy regarding the optimal composition of dialysate, especially with regard to sodium, 6-9 potassium, [10][11][12] and bicarbonate. [13][14][15] Differences in dialysate composition may influence both clinical and patient related outcomes.…”