Acute Kidney Injury

Abstract

Acute kidney injury (AKI) is defined as the deterioration in kidney function, detected by an increase in serum creatinine and decrease in glomerular filtration rate (GFR). Different classification systems exist for the diagnosis of AKI. Urine output can be variable, ranging from non-oliguria to anuria. AKI is classified into prerenal, intrinsic renal, and postrenal depending on the etiology. Common causes of AKI include volume depletion, acute tubular necrosis, acute interstitial nephritis (AIN), and urinary obstruction. A thorough history, review of medications, and physical examination are essential to sort out the etiology of AKI. Assessment of the patient’s volume status is crucial. Initial laboratory workup includes blood testing and evaluation of urinalysis and urine sediment. A renal ultrasound is indicated if the underlying cause is not immediately apparent. Treatment of AKI is directed toward correcting the underlying etiology and providing supportive measures. Careful monitoring should be undertaken for indications that would prompt initiation of dialysis, such as refractory electrolyte and acid base disturbances, refractory volume overload, uremic encephalopathy, and uremic pericarditis.