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

Management Strategies for Acute Kidney Injury (AKI)

The management of AKI should follow a stage-based approach, 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
  • Increase ≥50% from baseline within three months 1

• Determine AKI etiology:

  • Prerenal (reduced kidney perfusion)
  • Intrinsic renal (direct kidney damage)
  • Postrenal (urinary tract obstruction)
  • HRS-AKI in cirrhosis patients 1

• Essential diagnostic tests:

  • Serum creatinine and electrolytes
  • Urinalysis
  • Urine output monitoring
  • Renal ultrasonography (particularly important in older males to rule out obstruction) 1

Immediate Management Steps

1. Discontinue Nephrotoxic Medications

   • Immediately stop NSAIDs, ACE inhibitors, and ARBs
   • Adjust dosages of all medications according to renal function 1

2. Identify and Treat Underlying Causes

   • Infections
   • Gastrointestinal bleeding
   • Hypovolemia
   • Contrast-induced nephropathy
   • Obstructive uropathy 1

3. Optimize Volume Status

   • Administer isotonic crystalloids for hypovolemia
   • Target mean arterial pressure of 65-70 mmHg
   • Consider albumin infusion for cirrhosis patients with AKI
   • Avoid fluid overload, which can worsen renal function 1

Ongoing Management and Monitoring

• Monitor renal function, electrolytes, and urine output closely
• Follow up with assessments every 2-4 days during hospitalization for patients who respond
• Evaluate renal function at 3 months post-AKI
• Check renal function every 2-4 weeks during the first 6 months after discharge 1

Indications for Renal Replacement Therapy

Consider renal replacement therapy for:

• Refractory hyperkalemia
• Severe metabolic acidosis
• Volume overload unresponsive to diuretics
• Uremic complications (encephalopathy, pericarditis, pleuritis)
• Severe electrolyte abnormalities 1

The timing of renal replacement therapy initiation remains controversial, with recent research not consistently demonstrating benefit to early start dialysis 2.

Prevention Strategies

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

Common Pitfalls to Avoid

• Delaying treatment of the underlying cause
• Excessive fluid administration leading to overload
• Relying solely on urine output as a marker of kidney function
• Failure to adjust medication dosages according to renal function
• Delayed nephrology consultation 1

When to Consider Nephrology Consultation

• 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 3

Long-term Considerations

Even a single episode of AKI increases the risk of cardiovascular disease, chronic kidney disease, and death, making early determination of etiology, appropriate management, and long-term follow-up essential 4.