What is the management for Acute Kidney Injury (AKI) in a clinical setting?

From the Guidelines

Management for Acute Kidney Injury (AKI) in the clinic should focus on identifying and treating the underlying cause while preventing further kidney damage, as recommended by the most recent guidelines and studies, including the 2022 expert review by the American Gastroenterological Association 1. The approach to managing AKI involves several key steps:

• Assessing volume status and ensuring adequate hydration if the patient is hypovolemic, or implementing fluid restriction if overloaded
• Discontinuing nephrotoxic medications, including NSAIDs, certain antibiotics, and ACE inhibitors/ARBs, as suggested by the KDIGO guidelines 1 and the 2022 expert review 1
• Monitoring electrolytes closely, particularly potassium, and treating hyperkalemia if present with insulin plus glucose, sodium polystyrene sulfonate (Kayexalate), or calcium gluconate for cardiac protection in severe cases
• Checking for urinary obstruction with bladder scan or ultrasound and placing a urinary catheter if needed
• Obtaining serial creatinine measurements to track kidney function recovery Some key considerations in managing AKI include:
• The frequency of follow-up depends on AKI severity, with mild cases potentially monitored every 2-3 days and severe cases requiring daily assessment
• For patients with significant metabolic derangements (BUN >100 mg/dL, creatinine >4 mg/dL), severe hyperkalemia unresponsive to medical management, volume overload causing respiratory distress, or uremic symptoms, urgent nephrology consultation and possible dialysis are indicated, as recommended by the 2020 systematic review and meta-analysis on determining the optimal time for liberation from renal replacement therapy in critically ill patients 1
• The use of biomarkers, decision support programs, and electronic alerts can aid in the diagnosis and management of AKI, as discussed in the 2020 KDIGO conference on controversies in acute kidney injury 1
• The management of AKI in patients with cirrhosis requires special consideration, including the use of albumin infusion and the treatment of hepatorenal syndrome, as recommended by the 2015 revised consensus recommendations of the International Club of Ascites 1 and the 2022 expert review by the American Gastroenterological Association 1.

From the Research

Diagnosis and Classification of Acute Kidney Injury (AKI)

• AKI is defined as an increase in serum creatinine or a decrease in urine output over hours to days 2
• The classification of AKI includes both changes in serum creatinine concentrations and urine output 3
• Kidney Disease: Improving Global Outcomes (KDIGO) defines AKI as an increase in the serum creatinine (SCr) level of 0.3 mg/dL or more within 48 hours, an SCr level increase of 1.5 times or more of the baseline level within 7 days, or a decrease in urine output to less than 0.5 mL/kg/hour for 6 hours 4

Management of AKI

• Treatment of AKI is aimed at addressing the underlying causes of AKI, and at limiting damage and preventing progression 3
• The key principles of AKI management include:
  • Treating the underlying disease
  • Optimizing fluid balance and hemodynamics
  • Treating electrolyte disturbances
  • Discontinuing or dose-adjusting nephrotoxic drugs
  • Dose-adjusting drugs with renal elimination 3
• Management also includes control of the underlying cause, achievement and maintenance of euvolemia, nutritional optimization, blood glucose control, and pharmacotherapy 4
• Fluid resuscitation or diuresis is guided by the volume status 4
• Renal replacement therapy (dialysis) is indicated for refractory hyperkalemia, volume overload, intractable acidosis, uremic encephalopathy, pericarditis, or pleuritis, and removal of certain toxins 5

Referral and Follow-up

• Emergent referral to a nephrology subspecialist is recommended for patients with stage 2 or 3 AKI, patients with stage 1 AKI and a concomitant, decompensated condition, or if the etiology of the AKI is unclear 4
• Urgent referral should be considered if the injury does not improve with treatment or if glomerulonephritis is suspected 4
• Early determination of etiology, management, and long-term follow-up of AKI are essential 2