Acute renal failure is the inadequacy of the kidneys in filtering blood, which results in the accumulation of waste and abnormal concentrations of electrolytes in the blood. Acute renal failure may result from very low blood pressure or from substances, such as sodium phosphate, which can damage the kidneys. Sodium phosphate is used clinically for purging the bowel of stool in preparation for a colonoscopy -- a study that investigates the colon for abnormalities, such as polyps and pre-cancerous lesions.
Normal Kidney Function
Normal kidney function depends on the degree of blood flow in the kidneys. Blood flow is created by the contractions of the heart, so kidney function depends on adequate functioning of the heart. The kidneys have a variety of functions, including the regulation of blood volume and pressure, regulation of blood pH, excretion of wastes, reabsorption of nutrients and conservation of electrolytes.
Sodium Phosphate
Sodium phosphate is just one of several clinically used chemicals that may result in renal failure. The use of tablet-based sodium phosphate has increased in recent times because it is better tolerated by patients in comparison to polyethylene glycol solution -- a liquid-based colon cleanser. According to a 2007 "Diabetes Care" article, sodium phosphate use may result in renal failure due to severely elevated phosphate levels in the blood after use. People at risk for sodium phosphate-induced renal failure include the elderly, people with a pre-existing kidney condition, people with high blood pressure and those using diuretics.
Symptoms Associated with Acute Renal Failure
The kidneys produce erythropoietin -- a hormone that stimulates red blood cell production. In acute renal failure, there is lack of erythropoietin, which results in reduced red blood cell production. Acute renal failure is associated with shortness of breath due to decreased red blood cell production. As wastes accumulate in the blood, a person with renal failure may experience changes in mental status. Other symptoms include tendency to bleed, swelling as a result of fluid overload, decreased urination, decreased appetite, shakiness of the hands and seizures.
Management of Acute Renal Failure
Acute renal failure is suspected based on presenting symptoms. A complete blood count, or CBC, and blood chemistry tests are performed when renal failure is suspected. Blood chemistry tests for levels of creatinine -- a molecule that is completely excreted by normally functioning kidneys. Renal failure is associated with increased levels of creatinine in the blood. Information about blood urea nitrogen, or BUN, and potassium are also provided by blood chemistry tests. A CBC tests for the concentration of the various cells that compose the blood, including red blood cells. A urine analysis may also be performed to test for urine compositions that are indicative of renal failure.
References
- "Diabetes Care"; Acute Renal Failure Following Oral Sodium Phosphate Bowel Preparation in Diabetes; Ronald C.W. Ma, MRCP, et al.; January 2007
- Medline Plus: Acute Kidney Failure
- "Harrison's Principles of Internal Medicine"; Kasper M.D., Braunwald M.D. and Fauci M.D.; 2005
