How to manage a patient with acute kidney injury (AKI) due to gastroenteritis who has adequate urine output after an anuric phase but rising creatinine levels?

Management of AKI Due to Gastroenteritis with Adequate Urine Output but Rising Creatinine

Despite the return of adequate urine output after an anuric phase, rising creatinine levels in a patient with AKI due to gastroenteritis requires continued aggressive management focused on treating the underlying cause, optimizing volume status, and avoiding nephrotoxins to prevent progression to chronic kidney disease. 1

Initial Assessment and Management

• Identify and treat the underlying cause:

  • Ensure adequate hydration with isotonic crystalloids (500-1000 mL initial bolus for hypovolemic patients, then reassess) 1
  • Treat ongoing gastroenteritis with appropriate antimicrobials if bacterial etiology is suspected
  • Monitor for and treat electrolyte abnormalities that commonly occur with gastroenteritis

• Medication management:

  • Discontinue all nephrotoxic medications (especially NSAIDs) 1, 2
  • Hold diuretics temporarily as they can worsen volume depletion 1, 2
  • Adjust medication dosages based on current kidney function 1

Monitoring and Supportive Care

• Daily monitoring:

  • Serum creatinine, BUN, electrolytes, and urinalysis 1
  • Strict intake and output measurements
  • Vital signs with attention to hemodynamic stability

• Volume management:

  • Despite adequate urine output, continue fluid resuscitation if clinical signs of hypovolemia persist
  • Use isotonic crystalloids rather than colloids for volume expansion 1
  • Target euvolemia based on clinical assessment (vital signs, skin turgor, mucous membranes, JVP)

• Nutritional support:

  • Provide 20-30 kcal/kg/day total energy intake 1
  • Do not restrict protein intake (0.8-1.0 g/kg/day in non-catabolic AKI patients) 1
  • Consider enteral nutrition if oral intake is inadequate

Clinical Pearls and Pitfalls

• Rising creatinine despite adequate urine output indicates ongoing kidney injury or delayed recovery of glomerular filtration, which is common in the recovery phase of AKI 2

• Pitfall to avoid: Do not assume kidney recovery based solely on urine output. Both urine output and serum creatinine should be used for monitoring AKI 2

• Caution: Creatinine may continue to rise for 24-48 hours after the initial insult has been addressed before it begins to improve 2

• Important consideration: The discrepancy between urine output and creatinine may reflect tubular injury with impaired concentrating ability but partial recovery of filtration 3

Indications for Nephrology Consultation

Consider nephrology consultation if:

• Creatinine continues to rise beyond 48-72 hours despite adequate hydration
• Severe electrolyte abnormalities develop (hyperkalemia, metabolic acidosis)
• Patient develops signs of volume overload despite adequate urine output
• Consideration for renal replacement therapy becomes necessary 1

Follow-up

• Schedule follow-up within 3 months to assess for development of chronic kidney disease 1
• More frequent monitoring for high-risk patients
• Monitor for complete normalization of kidney function

This approach addresses the paradoxical finding of rising creatinine despite adequate urine output, which can occur during the recovery phase of AKI due to gastroenteritis as tubular function recovers at different rates.