Signs and Symptoms of Intrinsic ARF
- Fever, rash, arthralgia (joint pain)associated with allergic interstitial nephritis
- Flank painassociated with renal artery or vein obstruction, severe glomerulonephritis
- Headache, dizziness, confusion, seizureassociated with malignant hypertension
- Oliguria (reduced urination), edema (swelling), hypertensionassociated with glomerulonephritis, vasculitis
- Papilledema (swollen optic disk), heart failureassociated with malignant hypertension
Intrinsic ARF Complications
Because excretion of sodium and potassium is impaired, levels of these minerals and the level of chloride in the blood become elevated. This condition is known as metabolic acidosis. Several other complications may occur during the course of intrinsic ARF, including the following:
- Hyperkalmia (high level of potassium in the blood)
- Hypermagnamesia (high level of magnesium in the blood)
- Hyperphosphatemia (high level of phosphates in the blood)
- Hypocalcemia (low level of calcium in the blood)
- Intravascular overload (excess fluid in the vessels due to impaired ability to urinate)
- Uremia (high level of nitrogenous wastes in the blood)
Intrinsic ARF Diagnosis
Diagnosis is based on results from blood tests and urinalysis, and on the patient's medical history and signs and symptoms.
Blood test results that show high levels of creatinine indicate renal ischemia, atheroembolism, or exposure to radiocontrast dye. Severe anemia (low red blood count) may indicate TTP-HUS. Hyperkalemia (high level of potassium), hyperphosphatemia (high level of phosphorous), and hypocalcemia (low level of calcium) occur in rhabdomyolysis.
Urinalysis shows many red and white cells in the urine, and the level of sodium may be high. Proteinuria is a common finding. Mild proteinuria suggests that failure is caused by injured tubules. Moderate proteinuria indicates glomerular injury. Heavy proteinuria occurs in allergic interstitial nephritis.
Renal biopsy is performed when laboratory test results suggest more than one possible cause of intrinsic ARF.
Ultrasound rules out postrenal obstruction (i.e., obstruction in the bladder or urethra) as the cause of symptoms.