Table 2 A summary of absolute or 'rescue therapy' indications for initiation of renal replacement therapy in critically ill patients

Metabolic

   Azotemia

Serum urea ≥ 36 mmol/L (100 mg/dL)

   Uremic complications

Encephalopathy, pericarditis, bleeding

   Hyperkalemia

K+ ≥ 6 mmol/L and/or electrocardiogram abnormalities

   Hypermagnesemia

≥ 4 mmol/L and/or anuria/absent deep tendon reflexes

Acidosis

Serum pH ≤ 7.15

Oligo-anuria

Urine output <200 mL/12 h or anuria

Fluid overload

Diuretic-resistant organ edema (that is, pulmonary edema) in the presence of acute kidney injury