Table 2.

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

Category	Characteristic
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

Adapted from [16].