What is the initial management of acute kidney injury?

Initial Management of Acute Kidney Injury

The initial management of acute kidney injury (AKI) must focus on identifying and treating the underlying cause, discontinuing nephrotoxic medications, optimizing volume status, and providing appropriate supportive care to prevent further kidney damage and reduce mortality. 1, 2

Step 1: Identify and Address Risk Factors

• Immediately discontinue all nephrotoxic medications including NSAIDs, aminoglycosides, and iodinated contrast media to prevent further kidney injury 2
• Hold diuretics, ACE inhibitors, ARBs, and beta-blockers when AKI is diagnosed to prevent worsening kidney function 3, 2
• Review all medications, including over-the-counter drugs, that may contribute to kidney injury and adjust dosages based on reduced GFR 1
• Identify and treat infections and other precipitating causes of AKI promptly 3

Step 2: Optimize Volume Status

• Assess volume status through clinical examination and potentially central venous pressure monitoring 1
• For hypovolemic patients, administer intravenous fluid resuscitation with isotonic crystalloids 1
• For patients with cirrhosis and AKI, administer intravenous albumin at a dose of 1 g/kg/day (maximum 100g/day) for two consecutive days 3, 2
• Monitor carefully for fluid overload, which can worsen outcomes in AKI, using urine output and vital signs 1, 2

Step 3: Hemodynamic Management

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

Step 4: Diagnostic Workup

• Obtain kidney ultrasound immediately to rule out obstructive uropathy, particularly in older men with prostatic hypertrophy 1, 4
• Monitor serum electrolytes, BUN, creatinine every 4-6 hours initially 1
• Track fluid balance with strict input/output measurements 1
• Perform urinalysis to detect hematuria, proteinuria, or abnormal urinary sediment to exclude structural renal diseases 3

Step 5: Supportive Care

• Monitor for signs of uremic complications and reassess need for renal replacement therapy (RRT) daily 1
• Manage metabolic acidosis with sodium bicarbonate in selected cases 2
• Avoid overly rapid correction of hyponatremia, which can lead to osmotic demyelination syndrome 1

Indications for Renal Replacement Therapy

• Consider RRT for severe oliguria unresponsive to fluid resuscitation, severe metabolic derangements, uremic symptoms, and fluid overload 1
• Do not delay RRT when clear indications exist, as this increases mortality 1

Prevention of Nephrotoxicity

• Avoid combinations of nephrotoxic drugs, as each additional nephrotoxin increases the odds of developing AKI by 53% 2
• Be particularly cautious with the "triple whammy" of NSAIDs, diuretics, and ACE inhibitors or ARBs 2
• Implement a comprehensive drug stewardship program that includes identification of patients at risk for AKI 1

Common Pitfalls to Avoid

• Inappropriate continuation of nephrotoxic medications during AKI recovery phase 1
• Overly aggressive fluid administration in non-hypovolemic patients 1
• Neglecting to adjust medication dosages as kidney function changes 1
• Failing to identify and address the underlying cause of AKI 1
• Withholding potentially nephrotoxic agents in life-threatening conditions when they are necessary 3

When to Consider Nephrology Consultation

• When there is inadequate response to supportive treatment 5
• For AKI without a clear cause 5
• For stage 3 or higher AKI 5
• For patients with preexisting stage 4 or higher chronic kidney disease 5
• When renal replacement therapy is being considered 5