From the Guidelines
Pre-renal acute kidney injury (AKI) and renal (intrinsic) AKI can be differentiated based on their distinct characteristics, with pre-renal AKI typically responding to fluid resuscitation and renal AKI requiring specific treatment for the underlying kidney damage. The key differences between pre-renal and renal AKI are outlined in the following table:
- BUN/creatinine ratio:
- Pre-renal AKI: >20:1
- Renal AKI: <15:1
- Urine sodium:
- Pre-renal AKI: <20 mEq/L
- Renal AKI: >40 mEq/L
- Fractional excretion of sodium (FENa):
- Pre-renal AKI: <1%
- Renal AKI: >2%
- Urine osmolality:
- Pre-renal AKI: >500 mOsm/kg
- Renal AKI: <350 mOsm/kg
- Urine sediment:
- Pre-renal AKI: normal
- Renal AKI: contains cellular casts, particularly muddy brown granular casts in acute tubular necrosis According to the KDIGO guidelines 1, management of AKI involves discontinuing nephrotoxic agents, ensuring volume status and perfusion pressure, and monitoring serum creatinine and urine output. It is essential to identify the underlying cause of AKI, whether pre-renal or renal, to provide appropriate treatment and improve patient outcomes. In pre-renal AKI, addressing the underlying cause of decreased perfusion is crucial, while in renal AKI, treatment focuses on managing the specific kidney injury, which may require renal replacement therapy 1. Understanding these differences is vital for clinicians to make informed decisions and provide optimal care for patients with AKI.
From the Research
Pre-renal AKI vs Renal AKI: Differences
The differences between pre-renal AKI and renal AKI can be summarized as follows:
- Definition: Pre-renal AKI is caused by decreased renal perfusion, whereas renal AKI is caused by intrinsic kidney damage 2, 3.
- Causes: Pre-renal AKI is often caused by volume depletion, heart failure, or liver disease, whereas renal AKI can be caused by ischemic injury, nephrotoxic exposures, or other factors 4, 3.
- Pathophysiology: Pre-renal AKI is characterized by reduced glomerular filtration rate (GFR) due to decreased renal perfusion, whereas renal AKI is characterized by damage to the kidney parenchyma 2, 3.
- Treatment: Treatment of pre-renal AKI focuses on restoring renal perfusion, whereas treatment of renal AKI may involve supportive care, such as fluid management, vasopressor therapy, and kidney replacement therapy (KRT) 4.
Comparison of Pre-renal and Renal AKI
A comparison of pre-renal and renal AKI is shown in the following table:
| Characteristic | Pre-renal AKI | Renal AKI |
|---|---|---|
| Cause | Decreased renal perfusion | Intrinsic kidney damage |
| Pathophysiology | Reduced GFR due to decreased renal perfusion | Damage to kidney parenchyma |
| Treatment | Restore renal perfusion | Supportive care, including fluid management, vasopressor therapy, and KRT |
Note: There is no relevant information in reference 5 to assist in answering this question, as it discusses the biological significance of cytochrome methylation and is not related to AKI.