Acute Renal Insufficiency (Failure)

Abstract

One of the primary roles of the kidneys is to filter waste material from the blood. The inability of the kidneys to do this leads to renal failure. Acute renal insufficiency (ARI) is defined as the sudden onset (<48 h) of impaired kidney function. This is represented by a rise in the serum creatinine or a decrease in the urine output. The serum creatinine serves as a useful biomarker for measuring the flow rate of fluids through the kidneys, termed the glomerular filtration rate (GFR). As the clearance of creatinine and GFR decrease, the serum creatinine correspondingly increases signifying impaired renal function. The most common formula used to estimate GFR is the Cockcroft–Gault formula:

$$ \mathrm{GF}{{\mathrm{R}}_{\mathrm{CG}}}=\frac{{\left( {140-\mathrm{Age}} \right)\times \mathrm{Weight}\ \left( {\mathrm{kg}} \right)}}{{72\times \mathrm{Serum}\ \mathrm{creatinine}\ \left( {\mathrm{mg}/\mathrm{dL}} \right)}}\times [0.85\ \mathrm{if}\ \mathrm{Female}] $$

$$ \frac{{\left[ {\left( {140-\mathrm{Age}} \right) \times \mathrm{Mass}\left( {\mathrm{in}\ \mathrm{kg}} \right)} \right]}}{{\left[ {72 \times \mathrm{Serum}\ \mathrm{creatinine}\left( {\mathrm{in}\ \mathrm{mg}/\mathrm{dL}} \right)} \right]}} $$