How to treat metabolic alkalosis in patients with End-Stage Renal Disease (ESRD)?

Treating Metabolic Alkalosis in ESRD

In ESRD patients with metabolic alkalosis, use conventional hemodialysis with standard bicarbonate dialysate (25-28 mmol/L) to safely and rapidly correct the alkalosis, even in severe cases with pH >7.60 and bicarbonate >55 mmol/L. 1

Pathophysiology in ESRD

• ESRD patients lose the kidney's primary compensatory mechanism for metabolic alkalosis—the ability to excrete alkaline urine—causing alkaline loads to accumulate rapidly 2, 3
• Once acid loss (from vomiting or gastric drainage) exceeds metabolic acid production, severe alkalemia develops with compensatory hypoventilation that can cause hypoxia and hypercarbia 2
• The absence of renal excretory capacity means that even modest ongoing losses can produce extreme alkalosis 3

Treatment Algorithm

Immediate Management

Use conventional hemodialysis with normal bicarbonate dialysate (25-28 mmol/L) as first-line therapy 1

• This approach has been proven effective and safe for rapid correction of severe metabolic alkalosis in ESRD patients 1
• Standard bicarbonate dialysis successfully corrects acid-base homeostasis without requiring specialized low-bicarbonate or acidic dialysate 2, 1
• Hydration and achieving normal central venous pressure alone will not correct the alkalosis in oliguric ESRD patients 1

For Extreme Cases (pH >7.60, HCO₃ >55 mmol/L)

Consider continuous renal replacement therapy (CRRT) when rapid correction poses risk of dialysis disequilibrium 4

• Use sustained low-efficiency dialysis (SLED) with blood flow 60 ml/min and dialysate flow 400 ml/min to achieve gradual correction over 24-26 hours 4
• CRRT allows controlled bicarbonate removal using single-pool kinetic modeling to predict and regulate systemic bicarbonate levels 4
• This approach mitigates pronounced decreases in plasma osmolality, particularly important in patients with concurrent hypernatremia 4

Dialysate Composition

Use either lactate or bicarbonate buffer in the dialysate for most ESRD patients 5

• Standard bicarbonate dialysate concentrations (25-28 mmol/L) are appropriate and effective 1
• Both lactate and bicarbonate can correct metabolic acidosis, but bicarbonate is preferred in patients with liver failure or lactic acidosis 5

Prevention Strategies

Implement prophylactic acid suppression in at-risk patients 1

• H₂ blockers or proton pump inhibitors have demonstrated prophylactic effect against metabolic alkalosis formation in ESRD patients with vomiting or gastric drainage 1
• This is particularly important given that ESRD patients cannot compensate through renal mechanisms 3

Critical Monitoring

• Monitor arterial blood gases to assess both alkalemia severity and degree of compensatory hypoventilation 2
• Check for hypoxia and hypercarbia resulting from respiratory compensation 2
• Assess mental status changes (stupor, seizures) which indicate severe alkalemia requiring urgent intervention 1

Common Pitfalls

Avoid regional citrate anticoagulation during dialysis in patients with pre-existing alkalosis 6

• Regional citrate dialysis delivers several hundred mEq of potential bicarbonate and can cause or worsen severe metabolic alkalosis 6
• This is particularly problematic with repeated treatments 6

Do not rely on fluid resuscitation alone 1

• Unlike metabolic alkalosis in patients with intact renal function, hydration will not correct the disorder in oliguric ESRD patients 1
• Dialysis is required to remove the excess bicarbonate 1, 3