Treatment of Acute Kidney Injury (AKI)
The first priority in managing AKI is to identify and treat the underlying cause while discontinuing all nephrotoxic medications to prevent further kidney damage. 1, 2
Initial Management
- Identify and treat the underlying cause of AKI through assessment of temporal sequence, other possible causes, and response to interventions 1
- Discontinue nephrotoxic medications including NSAIDs, aminoglycosides, and iodinated contrast media 1, 2
- Hold diuretics and beta-blockers when AKI is diagnosed to prevent further kidney injury 1
- Review all medications, including over-the-counter drugs, that may contribute to kidney injury 1
Fluid Management
- Use isotonic crystalloids rather than colloids (except in specific circumstances) for initial management of intravascular volume expansion in patients with AKI 2
- Administer intravenous albumin at a dose of 1 g/kg/day (up to 100g/day) for two consecutive days in patients with significant AKI, particularly those with cirrhosis and ascites 1, 2
- Use vasopressors in conjunction with fluids in patients with vasomotor shock with, or at risk for, AKI 2
- Monitor fluid status closely due to risk of pulmonary edema with excessive fluid administration 2
Specific Management Based on AKI Type
Prerenal AKI
- Optimize hemodynamics with fluid resuscitation and vasopressors if needed, targeting mean arterial pressure of at least 65 mmHg 1
- Consider vasopressor therapy if fluid resuscitation fails to restore adequate blood pressure 1
Hepatorenal Syndrome AKI (HRS-AKI)
- Administer vasoactive agents (terlipressin, norepinephrine, or midodrine plus octreotide) along with albumin when serum creatinine remains elevated despite initial management 2, 1
- For terlipressin: start with 1 mg every 4-6 hours, increasing to maximum 2 mg every 4-6 hours if no reduction in serum creatinine by at least 25% by day 3 2
- For midodrine: start at 7.5 mg and titrate to 12.5 mg three times daily with octreotide (100 mg titrated to 200 mg subcutaneously three times daily) 2
- For norepinephrine: use continuous IV infusion starting at 0.5 mg/h, increasing every 4 hours by 0.5 mg/h to maximum 3 mg/h 2
Prevention of Nephrotoxicity
- Avoid combinations of nephrotoxic drugs, as each additional nephrotoxin increases AKI odds by 53% 2, 1
- Be particularly cautious with the "triple whammy" of NSAIDs, diuretics, and ACE inhibitors or ARBs 2
- Avoid NSAIDs in elderly patients with creatinine clearance <30 ml/min 2
- Use therapeutic drug monitoring during aminoglycoside administration 2
Indications for Renal Replacement Therapy (RRT)
- Consider RRT for: 2, 3
- Refractory hyperkalemia
- Volume overload unresponsive to diuretics
- Severe metabolic acidosis
- Uremic complications (encephalopathy, pericarditis, pleuritis)
- Removal of certain toxins
- RRT may be used for AKI secondary to acute tubular necrosis and for HRS-AKI in potential liver transplant candidates 2
Follow-up and Monitoring
- Continue nephrotoxin avoidance during the recovery phase to prevent re-injury 2, 1
- Perform serial follow-up measurements of serum creatinine and proteinuria after an episode of AKI to diagnose renal impairment and prevent progression 2, 4
- Consider nephrology consultation for: 5
- Inadequate response to supportive treatment
- AKI without a clear cause
- Stage 3 or higher AKI
- Preexisting stage 4 or higher chronic kidney disease
- Need for renal replacement therapy
Common Pitfalls and Caveats
- Avoid starch-containing fluids in patients with AKI as they can cause harm 2
- Avoid albumin resuscitation in patients with traumatic brain injury 2
- Monitor for ischemic side effects of vasoactive medications (terlipressin, norepinephrine) including angina and ischemia of fingers, skin, and intestine 2
- Recent evidence suggests that specialized kidney action teams providing early recommendations may not significantly improve outcomes despite higher implementation rates of recommendations 6