What is the initial management of acute kidney injury (AKI)?

Initial Management of Acute Kidney Injury (AKI)

The initial management of acute kidney injury should include reassessment of the underlying etiology, precise measurement of kidney function, withdrawal of nephrotoxic medications, optimization of hemodynamic status, and management of complications. 1

Immediate Assessment and Interventions

Step 1: Identify and Address Risk Factors

• Discontinue nephrotoxic medications immediately 2:

  • NSAIDs
  • Aminoglycosides
  • Contrast agents
  • ACE inhibitors/ARBs
  • Vasodilators
  • Diuretics (reduce or withdraw)

• Review all medications including over-the-counter drugs 1

Step 2: Optimize Volume Status

• Assess volume status through physical examination and clinical parameters
• For hypovolemic patients: Administer isotonic crystalloids rather than colloids 2
• For patients with suspected hypovolemia: Consider plasma volume expansion with:
  • Crystalloids
  • Albumin (1 g per kg bodyweight per day for two consecutive days) 1
  • Blood products (in patients with AKI due to gastrointestinal bleeding) 1

Step 3: Identify and Treat Underlying Causes

• Promptly recognize and treat bacterial infections when diagnosed or suspected 1
• Identify common precipitating factors 2:
  • Infections
  • GI bleeding
  • Excessive diuresis
  • Volume depletion
  • Tense ascites

Step 4: Monitor Kidney Function and Complications

• Monitor serum creatinine daily to assess AKI stage 1
• Identify complications requiring immediate attention 1:
  • Fluid overload
  • Acidosis
  • Hyperkalemia

Management Based on AKI Severity

For Stage 1 AKI:

• Implement all steps above
• Close monitoring with reassessment of kidney function within 48 hours 1
• If no response to initial measures, escalate management as for higher stages

For Stage 2-3 AKI:

• More aggressive management with all interventions above
• Consider nephrology consultation if 1, 2:
  • Etiology is unclear
  • Subspecialist care is needed
  • No response to initial management

Indications for Renal Replacement Therapy

• Refractory hyperkalemia
• Volume overload unresponsive to diuretics
• Severe metabolic acidosis
• Uremic symptoms (encephalopathy, pericarditis, pleuritis)
• Certain toxin ingestions 2

Follow-up Management

• For patients who respond with return of serum creatinine to within 0.3 mg/dL of baseline:

  • Close monitoring during hospitalization (check serum creatinine every 2-4 days)
  • Outpatient follow-up every 2-4 weeks for first 6 months after discharge 1

• Evaluate kidney function 3 months after AKI episode to screen for development of chronic kidney disease 2

Important Caveats

• AKI is not self-limiting but strongly linked to increased risk of chronic kidney disease, subsequent AKI episodes, and future mortality 2

• Higher stages of AKI are associated with higher mortality risk and worse clinical outcomes 2

• eGFR equations used for chronic kidney disease are not accurate for assessment of renal function in persistent AKI 1

• Timed urine creatinine clearance is currently the best available estimate of kidney function for patients with persistent AKI in steady state 1

• Avoid excessive fluid administration in euvolemic or hypervolemic patients 2