Dialysis Indications in Acute Kidney Injury
Dialysis should be initiated urgently when severe oliguria is unresponsive to fluid resuscitation, severe metabolic acidosis develops, or uremic complications (encephalopathy, pericarditis, pleuritis) occur, regardless of KDIGO stage. 1
Absolute Indications for Renal Replacement Therapy
The decision to initiate dialysis is not based on KDIGO stage alone but rather on specific clinical complications that develop during AKI:
- Refractory hyperkalemia that does not respond to medical management requires urgent dialysis 1, 2
- Severe volume overload unresponsive to diuretic therapy, particularly in the setting of fluid accumulation in ICU patients 1, 3
- Intractable metabolic acidosis that cannot be corrected with medical therapy 1, 2
- Uremic complications including encephalopathy, pericarditis, or pleuritis mandate immediate renal replacement therapy 1, 2
- Removal of certain dialyzable toxins in cases of poisoning or overdose 2
KDIGO Stage 3 and Dialysis Consideration
While KDIGO Stage 3 AKI is the most severe classification, the stage itself does not automatically trigger dialysis:
- Stage 3 criteria include creatinine ≥3.0× baseline, absolute creatinine ≥4.0 mg/dL (with acute rise ≥0.3 mg/dL), urine output <0.3 mL/kg/h for ≥24 hours, anuria ≥12 hours, or initiation of renal replacement therapy 1
- The inclusion of "initiation of RRT" as a Stage 3 criterion means that dialysis defines Stage 3, not the other way around 1
- Stage 3 AKI is strongly correlated with increased mortality, but dialysis timing depends on clinical complications rather than stage assignment 1
Daily Reassessment Protocol
- Reassess the need for continued RRT daily once initiated, as some patients may recover renal function and no longer require dialysis 1
- Monitor serum electrolytes, BUN, and creatinine every 4–6 hours initially in severe AKI to guide dialysis decisions 1
Common Pitfalls to Avoid
- Delaying RRT when clear indications exist increases mortality—do not wait for arbitrary creatinine thresholds if uremic complications or refractory electrolyte abnormalities develop 1
- Failing to recognize that Stage 3 AKI requiring dialysis has approximately four-fold increased hospital mortality compared to lower stages 4, 1
- In cirrhotic patients, urine output criteria are unreliable due to diuretic use and sodium retention, so focus on creatinine changes and clinical complications when considering dialysis 1
Hemodynamic Support Before Dialysis
- Maintain adequate mean arterial pressure >65 mmHg to ensure renal perfusion and potentially avoid dialysis in prerenal AKI 1
- For hypovolemic patients, provide isotonic crystalloid resuscitation rather than colloids before considering dialysis 1
- In cirrhotic patients with Stage 2–3 AKI, administer albumin 1 g/kg/day (maximum 100 g) for 2 days plus vasoactive therapy (terlipressin preferred, or norepinephrine, or midodrine plus octreotide) before dialysis, as this may reverse hepatorenal syndrome 1