Chronic renal failure is a gradual and progressive loss of the ability of the kidneys to excrete wastes, concentrate urine, and conserve electrolytes.
Causes, incidence, and risk factors
Unlike acute renal failure with its sudden reversible failure of kidney function, chronic renal failure is slowly progressive. It most often results from any disease that causes gradual loss of kidney function. It can range from mild dysfunction to severe kidney failure. Progression may continue to end-stage renal disease (ESRD).
Chronic renal failure usually occurs over a number of years as the internal structures of the kidney are slowly damaged. In the early stages, there may be no symptoms. In fact, progression may be so gradual that symptoms do not occur until kidney function is less than one-tenth of normal.
Chronic renal failure and ESRD affect more than 2 out of 1,000 people in the United States. Diabetes and hypertension are the two commonest causes and account for approximately two thirds of the cases of chronic renal failure and ESRD. Other major causes include the following:
Glomerulonephritis of any type (one of the most common causes)
Polycystic kidney disease
Alport syndrome
Reflux nephropathy
Obstructive uropathy
Kidney stones and infection
Analgesic nephropathy
Chronic renal failure results in the accumulation of fluid and waste products in the body, causing azotemia and uremia. Azotemia is the buildup of nitrogen waste products in the blood. It may occur without symptoms. Uremia is the state of ill health resulting from renal failure. Most body systems are affected by chronic renal failure. Fluid retention and uremia can cause many complications.
Symptoms
Initial symptoms may include the following:
Unintentional weight loss
Nausea, vomiting
General ill feeling
Fatigue
Headache
Frequent hiccups
Generalized itching (pruritus)
Later symptoms may include the following:
Increased or decreased urine output
Need to urinate at night
Easy bruising or bleeding;
May have blood in the vomit or in stools
Decreased alertness
drowsiness, somnolence, lethargy
confusion, delirium
coma
Muscle twitching or cramps
Seizures
Uremic frost — deposits of white crystals in and on the skin
Decreased sensation in the hands, feet, or other areas
Additional symptoms that may be associated with this disease:
Excessive nighttime urination
Excessive thirst
Abnormally dark or light skin
Paleness
Nail abnormalities
Breath odor
High blood pressure
Loss of appetite
Agitation
Signs and tests
Blood pressure may be high, with mild to severe hypertension. A neurologic examination may show polyneuropathy. Abnormal heart or lung sounds may be heard with a stethoscope.
A urinalysis may show protein or other abnormalities. An abnormal urinalysis may occur 6 months to 10 or more years before symptoms appear.
Creatinine levels progressively increase.
BUN is progressively increased.
Creatinine clearance progressively decreases.
Potassium test may show elevated levels.
Arterial blood gas and blood chemistry analysis may show metabolic acidosis.
Changes that indicate chronic renal failure, including both kidneys being smaller than normal, may be seen on:
renal or abdominal X-ray
abdominal CT scan
abdominal MRI
abdominal ultrasound.
This disease may also alter the results of the following tests:
urinary casts
renal scan
PTH
serum magnesium – test
erythropoietin
Treatment
Treatment focuses on controlling the symptoms, minimizing complications, and slowing the progression of the disease.
Associated diseases that cause or result from chronic renal failure must be controlled. Hypertension, congestive heart failure, urinary tract infections, kidney stones, obstructions of the urinary tract, glomerulonephritis, and other disorders should be treated as appropriate.
Blood transfusions or medications such as iron and erythropoietin supplements may be needed to control anemia.
Fluid intake may be restricted, often to an amount equal to the volume of urine produced. Dietary protein restriction may slow the build-up of wastes in the bloodstream and control associated symptoms such as nausea and vomiting. Salt, potassium, phosphorus, and other electrolytes may be restricted.
Dialysis or kidney transplant may be required eventually.
Prevention
Treatment of the underlying disorders may help prevent or delay development of chronic renal failure. Diabetics should control blood sugar and blood pressure closely and should refrain from smoking.