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:
- Urinary sodium < 15 mmol/liter[2]
- Fractional excretion of sodium in the urine of < 1%[2][3]
- Fractional excretion of urea nitrogen < 35%. [2]
- Ratio of urinary to plasma creatinine of > 20.[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%.[3] Causes include:
- Glomerulonephritis (GN). This is characterized by significant proteinuria, red cells in the urine (possibly dysmorphic in appearance), and red-cell casts.[4] GN may be caused by vasculitis.
- Acute tubular necrosis (ATN). ATN is characterized by pigmented granular casts in the urine sediment.[4] Causes of ATN include radiocontrast media and non-steroidal anti-inflammatory agents.
- Interstitial nephritis.
- Drug induced. Many drugs can cause acute kidney injury. Vancomycin is associated with acute kidney injury if trough levels are above 15 microg/mL.[5]
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.[6]
If fluid resuscitation is used, the type of fluid probably does not matter according to a meta-analysis of randomized controlled trials by the Cochrane Collaboration.[7]
Renal replacement therapy
Prevention
Administration of atrial natriuretic peptide prior to major surgery may reduce acute kidney injury.[8]
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 2.2 2.3 Steinman TI, Samir AE, Cornell LD (August 2008). "Case records of the Massachusetts General Hospital. Case 27-2008. A 64-year-old man with abdominal pain, nausea, and an elevated level of serum creatinine". N. Engl. J. Med. 359 (9): 951–60. DOI:10.1056/NEJMcpc0804600. PMID 18753652. Research Blogging.
- ↑ 3.0 3.1 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]
- ↑ 4.0 4.1 Rabb H, Colvin RB (2007). "Case records of the Massachusetts General Hospital. Case 31-2007. A 41-year-old man with abdominal pain and elevated serum creatinine". N. Engl. J. Med. 357 (15): 1531–41. DOI:10.1056/NEJMcpc079024. PMID 17928602. Research Blogging.
- ↑ Hidayat LK, Hsu DI, Quist R, Shriner KA, Wong-Beringer A (2006). "High-dose vancomycin therapy for methicillin-resistant Staphylococcus aureus infections: efficacy and toxicity". Arch. Intern. Med. 166 (19): 2138–44. DOI:10.1001/archinte.166.19.2138. PMID 17060545. Research Blogging.
- ↑ 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.
- ↑ Perel P, Roberts I (2007). "Colloids versus crystalloids for fluid resuscitation in critically ill patients". Cochrane Database Syst Rev (4): CD000567. DOI:10.1002/14651858.CD000567.pub3. PMID 17943746. Research Blogging.
- ↑ Nigwekar SU, Navaneethan SD, Parikh CR, Hix JK (February 2009). "Atrial natriuretic peptide for management of acute kidney injury: a systematic review and meta-analysis". Clin J Am Soc Nephrol 4 (2): 261–72. DOI:10.2215/CJN.03780808. PMID 19073785. Research Blogging.