What are the initial management steps for acute kidney injury?

Initial Management Steps for Acute Kidney Injury

The initial management of acute kidney injury (AKI) should focus on removing risk factors, optimizing fluid status, and identifying the underlying cause to prevent progression and reduce mortality.

Step 1: Risk Factor Identification and Removal

• Medication review and adjustment:

  • Withdraw all nephrotoxic medications including NSAIDs, aminoglycosides, and iodinated contrast media 1
  • Reduce or withdraw diuretic therapy 1
  • Discontinue vasodilators 1
  • Adjust dosing of all medications according to current renal function 2

• Identify and treat underlying infections:

  • Prompt recognition and early treatment of bacterial infections when diagnosed or suspected 1
  • For patients with spontaneous bacterial peritonitis, include albumin infusion according to current guidelines 1

Step 2: Volume Status Assessment and Management

• For hypovolemic patients:

  • Administer balanced crystalloid solutions (e.g., lactated Ringer's) rather than 0.9% saline or colloids 3
  • Initial fluid administration at 75-100 mL/hr to avoid fluid overload 3
  • In patients with cirrhosis and ascites, consider intravenous albumin at 1 g/kg bodyweight per day for two consecutive days (maximum 100g/day) 1
  • For patients with gastrointestinal bleeding, consider blood transfusion 1

• For euvolemic or hypervolemic patients:

  • Avoid fluid boluses, particularly in patients with cardiovascular disease or cerebrovascular disease 3
  • Monitor for signs of hypervolemia 3
  • Consider vasopressors in conjunction with fluids to maintain adequate perfusion 3

• Monitoring parameters:

  • Target urine output >0.5 mL/kg/hr 3
  • Reassess fluid status every 4-6 hours 3
  • Monitor vital signs, daily weights, and intake/output balance 3

Step 3: Diagnostic Evaluation

• Laboratory assessment:

  • Serum creatinine measurement 4
  • Complete blood count 4
  • Urinalysis 4
  • Fractional excretion of sodium 4
  • Serum and urine electrolytes 2

• Imaging:

  • Renal ultrasonography to rule out obstruction, particularly in older men 4
  • For trauma patients with suspected renal injury, perform IV contrast-enhanced CT with immediate and delayed images 1

Step 4: Management Based on AKI Stage

While the KDOQI Work Group expressed concerns about stage-based management recommendations due to lack of evidence 1, the following approach is generally recommended:

• Stage 1 AKI:

  • Close monitoring 1
  • Remove risk factors 1
  • Plasma volume expansion in case of hypovolemia 1
  • For patients who respond with return of serum creatinine to within 0.3 mg/dL of baseline, follow closely with assessment every 2-4 days during hospitalization 1

• Stage 2-3 AKI:

  • Withdrawal of diuretics (if not already done) 1
  • Volume expansion with albumin (1 g/kg) for 2 days in patients with cirrhosis 1
  • Consider nephrology consultation 2
  • Consider renal replacement therapy for:
    • Refractory hyperkalemia
    • Volume overload
    • Intractable acidosis
    • Uremic complications (encephalopathy, pericarditis, pleuritis)
    • Removal of certain toxins 4

Special Considerations

• For patients with cirrhosis:

  • Follow the International Club of Ascites algorithm for AKI management 1
  • Consider hepatorenal syndrome (HRS) diagnosis if no response after 2 days of diuretic withdrawal and plasma volume expansion 1

• For trauma patients:

  • Use non-invasive management strategies in hemodynamically stable patients 1
  • Perform immediate intervention (surgery or angioembolization) in hemodynamically unstable patients 1

• For patients with urinary obstruction:

  • Immediate placement of a Foley catheter followed by balanced crystalloid fluid resuscitation 3

Follow-up

• Evaluate patients with AKI for resolution, new onset, or worsening of pre-existing CKD at 3 months 1
• For patients who had AKI stage 1 and recovered, check renal function as outpatients at least every 2-4 weeks during the first 6 months after discharge 1

Common Pitfalls to Avoid

• Delaying treatment while waiting for diagnostic certainty
• Continuing nephrotoxic medications
• Excessive fluid administration leading to volume overload
• Inadequate monitoring of fluid status and urine output
• Failure to consider renal replacement therapy when indicated
• Neglecting post-discharge follow-up, as even one episode of AKI increases risk of cardiovascular disease, CKD, and death 5