Indications for Dialysis in Hyperkalemia
Dialysis is indicated for hyperkalemia when medical therapy fails to control life-threatening potassium levels, particularly in patients with severe renal impairment, oliguria/anuria, or ongoing potassium release syndromes. 1
Absolute Indications for Dialysis
The following clinical scenarios mandate urgent dialysis for hyperkalemia:
- Serum potassium >6.5 mEq/L unresponsive to medical therapy (calcium, insulin/glucose, albuterol, potassium binders) 1
- Persistent hyperkalemia despite aggressive medical management 2
- Oliguria or anuria (inability to excrete potassium renally) 1
- End-stage renal disease (ESRD) with severe hyperkalemia 1, 3
- Severe renal impairment (eGFR <15 mL/min) 1
- Ongoing potassium release syndromes:
- Persistent ECG changes despite medical therapy (peaked T waves, widened QRS, sine-wave pattern) 1
- Hemodynamic instability with severe hyperkalemia 4
Dialysis Modality Selection
Intermittent Hemodialysis (IHD)
IHD is the most effective and reliable method for rapid potassium removal in hemodynamically stable patients. 1, 3 It provides superior clearance compared to other modalities and is the gold standard for severe hyperkalemia. 1
Continuous Renal Replacement Therapy (CRRT)
CRRT is preferred over IHD in hemodynamically unstable patients (hypotensive, requiring vasopressors) because it minimizes rapid fluid shifts and reduces the risk of intradialytic hypotension. 2, 1 CRRT provides more gradual potassium removal with better hemodynamic tolerance. 2
Peritoneal Dialysis (PD)
PD should be reserved for situations where IHD and CRRT are unavailable. 2 PD has lower efficiency in removing potassium compared to IHD and CRRT, limiting its usefulness when significant solute removal is required. 2 However, PD can be effective in established PD patients presenting to emergency departments without HD access. 5
Clinical Context: When Medical Therapy Alone Is Sufficient
Dialysis is NOT necessary in all cases of severe hyperkalemia. 6 Conservative medical management may suffice in:
- Stable patients with intact renal function (eGFR >30 mL/min) who respond promptly to medical therapy 6, 3
- Patients with adequate urine output who can excrete potassium with loop diuretics 1
- Hyperkalemia from acute, reversible causes (e.g., medication-induced) in patients with normal baseline kidney function 6
Special Considerations in Tumor Lysis Syndrome
In tumor lysis syndrome, dialysis indications extend beyond hyperkalemia alone. 2 Dialysis may be initiated prophylactically before overt uremic symptoms develop in response to:
- Severe, progressive hyperphosphatemia (>6 mg/dL) 2
- Severe symptomatic hypocalcemia 2
- Volume overload unresponsive to diuretic therapy 2
- Severe metabolic acidosis 2
- Overt uremic symptoms (pericarditis, severe encephalopathy) 2
Frequent (daily) dialysis is recommended in tumor lysis syndrome due to continuous release of potassium and other metabolites from lysed tumor cells. 2
Critical Pitfalls to Avoid
- Do not delay dialysis in ESRD patients with severe hyperkalemia while attempting prolonged medical management—dialysis is definitive therapy in this population. 1, 7
- Do not rely solely on temporizing measures (calcium, insulin, albuterol) in patients with impaired renal function—these do not remove potassium from the body. 1
- Do not use peritoneal dialysis as first-line therapy when IHD or CRRT are available—PD is significantly less efficient. 2
- In hemodynamically unstable patients, choose CRRT over IHD to avoid exacerbating hypotension. 2, 1
Monitoring Post-Dialysis
Potassium levels can rebound 4-6 hours post-dialysis as intracellular potassium redistributes to the extracellular space. 1 Monitor patients with severe initial hyperkalemia (>6.5 mEq/L) or ongoing potassium release syndromes every 2-4 hours initially. 1 Consider initiating potassium binders (patiromer or sodium zirconium cyclosilicate) to prevent recurrence. 1