From the Guidelines
Acute kidney injury (AKI) is diagnosed using the KDIGO criteria, which define AKI as an increase in serum creatinine by ≥0.3 mg/dL within 48 hours, or an increase to ≥1.5 times baseline within 7 days, or urine output less than 0.5 mL/kg/h for 6 hours, as recommended by the most recent study 1.
Diagnostic Criteria for AKI
The diagnostic criteria for AKI are based on the KDIGO guidelines, which consider the following:
- Increase in serum creatinine by ≥0.3 mg/dL within 48 hours
- Increase in serum creatinine to ≥1.5 times baseline within 7 days
- Urine output less than 0.5 mL/kg/h for 6 hours These criteria are used to diagnose and stage AKI, with staging ranging from 1 to 3, depending on the severity of the injury.
Management of AKI
Management of AKI focuses on:
- Identifying and treating the underlying cause
- Discontinuing nephrotoxic medications
- Ensuring adequate hydration
- Maintaining hemodynamic stability
- Correcting electrolyte imbalances, particularly hyperkalemia
- Adjusting medication dosages based on estimated kidney function
- Considering renal replacement therapy (dialysis) for severe cases
Importance of Early Detection and Treatment
Early detection and treatment of AKI are crucial to prevent progression to more severe forms of kidney injury and to reduce morbidity and mortality. Daily monitoring of fluid balance, electrolytes, and kidney function is essential, as is maintaining adequate nutrition. The underlying pathophysiology of AKI involves decreased renal perfusion, direct tubular injury, or urinary tract obstruction, which is why addressing the specific cause while supporting kidney function is crucial for recovery, as noted in 2 and 3.
From the Research
Diagnostic Criteria for Acute Kidney Injury
The diagnostic criteria for acute kidney injury (AKI) are defined by the Kidney Disease: Improving Global Outcomes (KDIGO) group as:
- An increase in the serum creatinine (SCr) level of 0.3 mg/dL or more within 48 hours 4, 5
- An SCr level increase of 1.5 times or more of the baseline level within 7 days 4, 5
- A decrease in urine output to less than 0.5 mL/kg/hour for 6 hours 4, 5
Management Options for Acute Kidney Injury
The management of AKI includes:
- Control of the underlying cause 4, 6
- Achievement and maintenance of euvolemia 4
- Nutritional optimization 4
- Blood glucose control 4
- Pharmacotherapy 4
- Treatment with fluid resuscitation or diuresis guided by the volume status 4
- Emergent referral to a nephrology subspecialist for patients with stage 2 or 3 AKI, or if the etiology of the AKI is unclear 4
Importance of Early Diagnosis and Treatment
Early diagnosis and treatment of AKI are critical for improving outcomes 6, 7. The use of biomarkers such as interleukin-18, neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 may aid in the early diagnosis of AKI 8. Team-based approaches for prevention, early diagnosis, and aggressive management are critical for improving outcomes 6.