Acute kidney injury
Acute kidney injury, previously called acute renal failure, is defined as as "An abrupt (within 48 hours) reduction in kidney function currently defined as an absolute increase in serum creatinine of more than or equal to 0.3 mg/dl (≥ 26.4 μmol/l), a percentage increase in serum creatinine of more than or equal to 50% (1.5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour for more than six hours)."[1]
Classification
Prerenal
This is characterized by fractional excretion of sodium in the urine of < 1%.[2] Causes include:
- Hypovolemia
- Hepatorenal syndrome
- Vascular disease
Intrarenal
Also simply called 'renal', this is characterized by fractional excretion of sodium in the urine of > 1%.[2] Causes include:
- Glomerulonephritis (GN). This is characterized by significant proteinuria, red cells in the urine (possibly dysmorphic in appearance), and red-cell casts. GN may be caused by vasculitis.
- Acute tubular necrosis (ATN). ATN is characterized by pigmented granular casts in the urine sediment. Causes of ATN include radiocontrast media and non-steroidal antiiinflammatory agents.
- Interstitial nephritis.
Post-renal
This is characterized by symptoms of obstruction and sometimes by anuria.
Treatment
The underlying cause of the kidney injury should be treated. Diuresis has been investigated as a nonspecific treatment, but no benefit was found.[3]
References
- ↑ Mehta RL, Kellum JA, Shah SV, et al (2007). "Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury" 11 (2): R31. DOI:10.1186/cc5713. PMID 17331245. Research Blogging.
- ↑ 2.0 2.1 Miller TR, Anderson RJ, Linas SL, et al (1978). "Urinary diagnostic indices in acute renal failure: a prospective study". Ann. Intern. Med. 89 (1): 47–50. PMID 666184. [e]
- ↑ Ho KM, Sheridan DJ (2006). "Meta-analysis of frusemide to prevent or treat acute renal failure". BMJ 333 (7565): 420. DOI:10.1136/bmj.38902.605347.7C. PMID 16861256. Research Blogging.