What are the initial approaches for treating Acute Kidney Injury (AKI)?

Initial Approaches for Treating Acute Kidney Injury (AKI)

The initial management of AKI should focus on identifying and treating the underlying cause, removing nephrotoxic agents, optimizing hemodynamics, and ensuring adequate renal perfusion to prevent further kidney damage and improve outcomes. 1, 2

Step 1: Medication Review and Adjustment

• Review all medications (including over-the-counter drugs) and discontinue potential nephrotoxic agents such as NSAIDs, aminoglycosides, and iodinated contrast media 1, 2
• Reduce or withdraw diuretic therapy to prevent further kidney injury 3, 2
• Be particularly cautious with the "triple whammy" combination of NSAIDs, diuretics, and ACE inhibitors or ARBs, which significantly increases AKI risk 2
• Hold beta-blockers when AKI is diagnosed to prevent further kidney injury 2

Step 2: Volume Status Assessment and Correction

• Administer intravenous fluids (crystalloids preferred over colloids) for patients with clinically suspected hypovolemia 1, 2
• For patients with significant AKI, consider intravenous albumin at a dose of 1 g/kg/day for two consecutive days 2
• In cirrhotic patients with ascites and AKI, plasma volume expansion with intravenous albumin (1 g/kg bodyweight per day for two consecutive days, maximum 100g/day) is recommended 3, 1
• Monitor for fluid overload using urine output, vital signs, and when indicated, echocardiography or CVP measurements 2

Step 3: Hemodynamic Optimization

• Target mean arterial pressure of at least 65 mmHg to ensure adequate renal perfusion in prerenal AKI 2
• Consider vasopressor therapy if fluid resuscitation fails to restore adequate blood pressure 2
• For hepatorenal syndrome AKI (HRS-AKI), administer vasoactive agents (terlipressin, norepinephrine, or midodrine plus octreotide) along with albumin when serum creatinine remains elevated despite initial management 2

Step 4: Additional Management Based on AKI Stage and Etiology

• For persistent AKI (continuing beyond 48 hours), reassess the underlying etiology and perform precise measurement of kidney function 3
• Additional monitoring should be considered to re-evaluate hemodynamic and volume status, adequacy of kidney perfusion, and to identify complications such as fluid overload, acidosis, and hyperkalemia 3
• For AKI in cirrhotic patients, follow a specific algorithm based on AKI staging:
  • Stage 1: Close monitoring, removal of risk factors, plasma volume expansion if hypovolemic 3
  • Stages 2-3: Withdrawal of diuretics and administration of albumin 3, 1

Step 5: Monitoring and Follow-up

• Monitor kidney function, urine output, and electrolytes closely during the acute phase of AKI 1
• Consider nephrology consultation if the etiology of AKI is unclear or subspecialist care is needed 3
• Timed urine creatinine clearance is currently the best available estimate of kidney function for patients with persistent AKI in the steady state 3
• Note that equations to estimate GFR in chronic kidney disease are not accurate for assessment of renal function in persistent AKI 3

Common Pitfalls to Avoid

• Delaying discontinuation of nephrotoxic medications can worsen AKI 1, 2
• Inadequate or delayed volume resuscitation in hypovolemic patients can exacerbate kidney injury 1
• Using combinations of nephrotoxic drugs increases the odds of developing or worsening AKI by 53% per additional nephrotoxic agent 2
• Failing to identify and treat underlying infections, especially in cirrhotic patients 3
• Overlooking the need for follow-up after AKI recovery, as even one episode of AKI increases the risk of cardiovascular disease, chronic kidney disease, and death 4