Renal Failure

What is Acute Renal Failure (ARF)?

Acute Renal Failure (Acute Renal Insufficiency or Acute Renal Impairment) is the condition where kidneys suddenly stop functioning. Kidneys remove toxic metabolism products and contribute to keeping the balance of water and electrolytes in the human body. When kidneys stop functioning, metabolic debris, fluids and electrolytes accumulate in the body. This may cause problems that can even be fatal. 

What causes ARF?

Causes of ARF  can be classified in three categories: prerenal, renal and postrenal.

  • Prerenal ARF. A sudden significant reduction of blood flow towards kidneys. This may be due to a severe hemorrhage, injury or infection, called septicemia. Also, fluid deprivation (dehydration) may impair kidneys. 
  • Renal ARF. Some pharmaceutical agents, toxic substances or infections may impair kidneys and cause acute renal insufficiency. Such drugs are antibiotics -such as gentamicin and streptomycin- and analgesics -such as aspirin and ibuprofen.  There are also some antihypertensive drugs and contrast media used in radiological tests that are related to renal failure induction. 
  • Postrenal ARF. A sudden obstacle preventing the urine discharge from kidneys. This could be a stone in the urinary tract, prostate tumor, injury or dilation causing urinary retention.

High ARF risk groups are the elderly, the obese and patients with long-term health problems such as liver or kidney disease, diabetes, hypertension and heart failure. Also, ICU  (Intensive Care Unit) patients who have undergone large surgical operations or bone marrow transplantation. 

What are the symptoms of ARF?

ARF symptoms may include:

  • Low or no urinary output
  • Oedema, mainly in lower limbs
  • Anorexia (loss of appetite)
  • Agitation, Anxiety, Confusion, Drowsiness (somnolence)
  • Dyspnea, Chest pain

How is ARF diagnosed?

In hospitalized patients, the diagnosis is usually set based on blood tests done during their monitoring. As for other patients who will visit the physician with some of the above symptoms, it is their history and clinical examination that will raise the suspicion. Your doctor will ask for some blood tests to confirm it. These tests include blood urea and creatinine, as well as ultrasound renal screening to detect a potential obstruction. 

How is ARF treated?

The treatment depends on the specific etiology of every case of renal failure. In case of hemorrhage, this has to stop and there may be even need for blood transfusion. If renal failure is induced by some pharmaceutical agent, its administration should be immediately discontinued. If there is some obstacle obstructing urine flow, it has to be removed. At the same time, your doctor will regulate your diet, fluid and electrolyte intake. There are cases when some hemodialysis sessions may be recommended until kidneys recover and are able to respond to the needs of the body organism. 

Can ARF cause permanent problems?

Should the problem be diagnosed early and the cause be treated properly, renal impairment is fully restored within some days or weeks. In a small number of patients there may remain some degree of renal insufficiency. Only in very rare cases is there risk for renal failure to require hemodialysis. 

What is Chronic Renal Failure (CRF)?

Every kidney contains about one million tiny filtering units, called nephrons, which remove metabolism-produced waste and excess substances from blood. They also regulate water and electrolytes in the body. In some cases, nephrons start being impaired and from some point on they become insufficient; as a result, kidneys cannot carry out properly their role. This usually takes place gradually and in some cases chronic renal failure may suddenly be manifested, because metabolic waste and debris have in the meantime slowly accumulated in the body. Chronic Renal Failure is evaluated based on GFR (Glomerular Filtration Rate), a marker practically indicating the ability of the kidney to filter blood.

There are five (5) stages of renal failure, starting from mild renal impairment with normal GFR up to severe renal failure that requires hemodialysis.  

What causes CRF?

The most common CRF causes are:

  • High Blood Pressure
  • Diabetes Mellitus
  • Various Diseases afflicting kidneys (Glomerulonephritis, Polycystic Kidney Disease etc)
  • Renal Artery Stenosis
  • Long-term Pharmaceutical Treatment, such as antibiotics

What are the symptoms of CRF?

During the first stages of the disease -that may last from a few months to 30 years- most patient have no symptoms. This is called 'latent' (silent) stage of the disease. However, as the disease progresses, symptoms may occur , such as:

  • Reduced urine output
  • Lower limb edema
  • Fatigue, Drowsiness/ Somnolence, Fatigue
  • Nausea or/and even Vomiting
  • Anorexia (loss of appetite)
  • Headache and Sleeping problems
  • Loss of body weight
  • Confusion

How is CRF diagnosed?

Your physician will ask you to do some blood tests to evaluate your renal function and detect a potential anemia that often coexists with CRF. More specific tests will indicate GFR (Glomerular Filtration Rate) assessing the severity of the disease. This marker will determine also treatment decisions. If necessary, imaging tests will be done, such as CT scan to trace any potential conditions blocking urine flow from kidneys. In rare cases,  there may be need for renal biopsy during which a small specimen is obtained for pathologoanatomical examination to identify the cause that has induced renal impairment. 

How is CRF treated?

The first step is to treat the diseases causing it. Successful control of diabetes and blood pressure may stop or delay the impairment induced to kidneys. Also, body weight loss and physical exercise play a highly significant role, while your physician may recommend some pharmaceutical therapy. 

A Dietician will suggest a nutritional program (diet) and the amount of liquids to be daily consumed. In addition, smoking and alcohol consumption should be avoided. You should always inform your physician before taking any medication. .

What if the disease progresses?

From some point on, kidneys cannot respond to body needs and this affects the whole organism. Should the problem not be treated properly, there is even fatal risk. When there is such a severe chronic renal failure, alternative options are:

  • Hemodialysis. It is a procedure applied every second day, in which a special device is used to 'clean' the body by filtering waste products that cannot be removed by kidneys. This is not a therapy but it actually substitutes renal function. 
  • Kidney Transplantation. It is the best choice, as long as one has no other health problem. The difficulty lies in finding transplant which usually takes a long time. In the meantime, one can be on assisted hemodialysis.

These two alternative therapeutic options have both advantages and disadvantages. Your therapist physician will help you decide which is the most appropriate for your case.