What are the management strategies for Acute Kidney Injury (AKI)?

Management Strategies for Acute Kidney Injury (AKI)

The management of AKI should be stage-based, focusing on identifying and treating the underlying cause while providing appropriate supportive care to prevent progression and reduce mortality. 1

Initial Assessment and Classification

• Classify AKI according to adapted KDIGO criteria:

  • Increase in serum creatinine >0.3 mg/dl from baseline within 48 hours, OR
  • Increase ≥50% from baseline within three months 1

• Determine AKI etiology:

  • Prerenal (hypovolemia, decreased cardiac output)
  • Intrinsic renal (ATN, glomerulonephritis)
  • Postrenal (obstruction)
  • HRS-AKI (in cirrhosis patients) 1

• Essential diagnostic tests:

  • Serum creatinine and electrolytes
  • Urinalysis (to detect hematuria, proteinuria, abnormal sediment)
  • Urine output monitoring (target >0.5 mL/kg/hr)
  • Renal ultrasonography (especially in older males to rule out obstruction) 1

Stage-Based Management Protocol

For All AKI Stages:

1. Discontinue nephrotoxic medications immediately:

   • NSAIDs, ACE inhibitors, ARBs
   • Adjust dosages of medications according to renal function
   • Consider discontinuing diuretics and beta-blockers in cirrhotic patients 1

2. Identify and treat underlying causes:

   • Infections (screen and treat promptly)
   • Gastrointestinal bleeding
   • Hypovolemia
   • Contrast-induced nephropathy
   • Obstructive uropathy 1

3. Volume status optimization:

   • For hypovolemia: Administer isotonic crystalloids (balanced crystalloids preferred over 0.9% NaCl) 2
   • Target MAP 65-70 mmHg 2
   • In cirrhosis with AKI: Consider albumin 1g/kg (maximum 100g) for two consecutive days 1
   • Avoid fluid overload which can worsen renal function 2

Stage-Specific Management:

Stage 1 AKI:

• Close monitoring of renal function, electrolytes, and urine output
• Follow-up assessment every 2-4 days during hospitalization for patients who respond 2
• In cirrhosis with AKI stage 1A (SCr <1.5 mg/dl): Withdraw diuretics and nephrotoxic drugs, volume expansion if needed 1
• In cirrhosis with AKI stage 1B (SCr ≥1.5 mg/dl): More aggressive management similar to higher stages 1

Stage 2-3 AKI:

• More intensive monitoring (consider ICU admission for stage 3)
• Consider nephrology consultation
• Evaluate for renal replacement therapy (RRT) indications:
  • Refractory hyperkalemia
  • Severe metabolic acidosis
  • Volume overload unresponsive to diuretics
  • Uremic complications (encephalopathy, pericarditis)
  • Severe electrolyte abnormalities 1, 2

Special Considerations

AKI in Cirrhosis:

• Discontinue diuretics, beta-blockers, and nephrotoxic drugs
• Administer albumin 1g/kg (max 100g) for two consecutive days if no obvious cause and AKI stage >1A
• Screen and treat infections aggressively
• For tense ascites with AKI: Therapeutic paracentesis with albumin infusion 1

Prevention Strategies:

• Avoid nephrotoxic medications when possible
• Ensure adequate volume status and perfusion pressure in high-risk patients
• Appropriate prophylaxis for contrast-induced AKI in high-risk patients
• Antibiotic prophylaxis for spontaneous bacterial peritonitis in cirrhosis 1

Follow-up and Monitoring

• Monitor for resolution, new onset, or worsening of pre-existing CKD
• Evaluate renal function at 3 months post-AKI
• Check renal function every 2-4 weeks during first 6 months after discharge 2
• More frequent monitoring for patients with incomplete recovery or pre-existing CKD 1

Common Pitfalls to Avoid

1. Delaying treatment of underlying cause
2. Excessive fluid administration leading to volume overload
3. Relying solely on urine output without considering other parameters
4. Failure to adjust medication dosages according to renal function
5. Delayed nephrology consultation for severe or complicated AKI 2

The stage-based approach to AKI management emphasizes early intervention to prevent progression, with treatment intensity escalating according to AKI severity, always prioritizing the identification and treatment of underlying causes while providing appropriate supportive care.