What is the next step in managing a patient admitted with Acute Kidney Injury (AKI)?

Management of Acute Kidney Injury (AKI)

The immediate management of a patient admitted with AKI should include identifying and treating the underlying cause, discontinuing nephrotoxic medications, optimizing volume status, and considering albumin administration in specific cases. 1, 2

Initial Assessment and Immediate Actions

• Diagnose AKI using established criteria: increase in serum creatinine by ≥0.3 mg/dL within 48 hours or ≥50% from baseline, or urine output <0.5 mL/kg/h for >6 hours 1
• Review and discontinue all potentially nephrotoxic medications including NSAIDs, certain antibiotics, and contrast agents 1, 2
• Hold diuretics, ACE inhibitors, ARBs, and vasodilators unless clinically contraindicated 1, 3
• Perform a rigorous search for infection (blood cultures, urine cultures, chest radiograph, and diagnostic paracentesis if ascites is present) 1
• Obtain kidney ultrasound to rule out obstructive causes 2

Volume Management

• Assess volume status through clinical examination (vital signs, skin turgor, mucous membranes, jugular venous pressure) 2
• For hypovolemic patients, administer appropriate volume expansion:
  • For patients without cirrhosis: isotonic crystalloids 4, 5
  • For patients with cirrhosis and AKI: albumin 1 g/kg/day (maximum 100 g) for two consecutive days 1
• Avoid excessive fluid administration in euvolemic or hypervolemic patients as fluid overload can worsen outcomes 6, 4
• Monitor fluid balance with strict input/output measurements 2

Special Considerations for Cirrhotic Patients

• For patients with cirrhosis and AKI, follow the International Club of Ascites (ICA) algorithm 1, 3:
  • Stage 1 AKI: Remove risk factors, expand plasma volume if hypovolemic 1
  • Stage 2-3 AKI: Withdraw diuretics and administer albumin 1 g/kg for 2 days 1
  • If no response after 48 hours and HRS criteria are met, initiate vasoconstrictors (terlipressin) with albumin 1
• In cirrhotic patients, furosemide should be used cautiously as it may precipitate hepatic encephalopathy 7

Laboratory Monitoring

• Monitor serum electrolytes, BUN, creatinine frequently (every 4-6 hours initially) 2, 7
• Check urine analysis for hematuria, proteinuria, or abnormal sediment to exclude structural renal diseases 2
• Consider urinary biomarkers (NGAL) to distinguish between acute tubular necrosis and hepatorenal syndrome in cirrhotic patients 1, 3

Nutritional Support

• Avoid excessive protein restriction, which can worsen nutritional status 2
• Monitor for and correct electrolyte abnormalities, particularly hypokalemia, which may develop with diuretic use 7

Common Pitfalls to Avoid

• Delaying treatment of underlying causes, especially infections 1, 2
• Continuing nephrotoxic medications during AKI recovery 2
• Overly aggressive fluid administration in non-hypovolemic patients 6, 5
• Neglecting to adjust medication dosages as kidney function changes 2, 7
• Using the "triple whammy" combination of NSAIDs, diuretics, and ACE inhibitors/ARBs 2

Indications for Renal Replacement Therapy

• Consider RRT for severe oliguria unresponsive to fluid resuscitation, severe metabolic derangements, uremic symptoms, or fluid overload 2
• In cirrhotic patients with HRS-AKI unresponsive to medical therapy, early consideration of RRT may be necessary 1

By following this structured approach to AKI management, focusing on identifying and treating the underlying cause while optimizing volume status and avoiding further kidney injury, you can improve outcomes for patients with this serious condition.