Chronic Kidney Disease

Chronic Kidney Disease

CKD is often thought of as a “silent” disease as symptoms of the disease are not seen until kidney function drops to 30-40% of normal. When function drops to 15% , this is called End Stage Renal Failure and patients must seek dialysis to filter toxins out of the blood.

See a quick video on the kidneys and kidney disease:
http://lifeblood.anaemiaworld.com/en/chronic-kidney-disease/chronic-kidney-disease.html
(see bottom left corner)

The Kidneys

One of the most important concepts for the health of our bodies is keeping it in homeostasis. The kidneys are a key mechanism of maintaining our body’s normal functions.

Another importance concept is the interrelatedness of our cardiovascular system and our urinary systems because:

The Kidneys:
1) filter our blood
2) maintain blood pressure
3) stimulate the production of red blood cells

Whenever we eat a meal or take a breath of fresh air, we are fueling our bodies with the materials that it needs to stay alive. The food is broken down in our stomachs and is absorbed into the blood stream. Oxygen from our lungs binds to red blood cells in the blood as well. Our body’s cells and tissues then use this fuel and empty its waste back into the blood stream. The blood then passes through the kidneys to be filtered. The waste is filtered and excreted in the form of urine, while remaining nutrients and red blood cells are reabsorbed into the bloodstream.

The kidneys are also important in maintaining blood pressure, and red blood cell production. Since most of us drink our 8 glasses of water per day (hopefully ), this loads our blood with more fluid. When this fluid volume raises our blood pressure too high, it signals for the kidneys to help drop this pressure by making us urinate. But if we do not drink enough water our fluid volume will lower. This signals our kidneys to release a hormone Renin, which triggers our body to conserve salt and water so that our blood pressure does not fall too low.

Since all of our blood passes through the kidneys, they sense the number of red blood cells and thus, the amount of oxygen that our bodies have. To maintain the red blood cell count, the hormone Erythropoietin is released and stimulates the bone marrow to produce blood cells.

What causes kidney disease?
The leading cause is Diabetes, second to Hypertension (high blood pressure). Other causes are Polycystic kidney disease, Glomerularnephritis, Reflux neuropathy, analgesic neuropathy, or kidney stones.

Testing: How do you know if your kidneys aren’t working?

1) The amount of blood that is filtered by the kidneys per minute is called the Glomerular Filtration Rate. This is a measure of the kidney’s function.

Normal kidneys filter about 120-125 ml per min (about ½ a cup). Kidney damage seen in CKD causes GFR to drop to 60ml per minute (about 4 tablespoons). Even more staggering, a person with ESRD has a GFR of 15 ml/min (about a tablespoon).
http://www.aafp.org/afp/20040901/869.html

2) A blood test can measure the amount of creatinine and the urea-nitrogen content in the bloodstream. These are toxins that can build up in the blood when the kidneys are damaged and cannot filter as well.

3) Protein or blood found in the urine is also a sign of kidney damage.

What are the symptoms of kidney disease?
• fatigue
- weakness
- increased urinary frequency
- back pain
- decreased urine output
- numbness and swelling in extremities

What are the complications of kidney disease?

As you know, the kidneys function in the urinary system and the cardiovascular system are interrelated. The majority of the time when the kidneys are damaged so are the cells that produce hormones that regulate blood pressure and red blood cell production. This can lead to two major complications: further increasing the high blood pressure, and also cause anemia.

Since the blood volume cannot be filtered and “peed out” in the urine, the blood begins to back up into the from the aorta into the left ventricle where the blood is normally pushed out. The increased pressure furthur backs up blood into the left atrium and into the lungs. This causes the lungs to become filled with fluid, called pulmonary edema, and reduces the amount of oxygen that is transferred with each inhalation. This added stress and reduction of oxygen can put the body at risk for congestive heart failure, cardiac tamponade, and other serious disorders.

Treatments:
To help treat renal failure keeping protein, cholesterol, and electrolyte levels low in the diet will help reduce pressure on the kidneys. Patients should be encouraged to refrain from smoking. Diabetic patients should also closely control their blood sugar.

Also very important is to stop all usage of over the counter pain relievers and anti-inflammatories such as aspirin, acetaminophen, and ibuprophen. Some forms of kidney disease are caused from excessive daily usage of these drugs. Patients with kidney disease caused by analgesic neuropathy have complications from using sometimes three or more doses per day for three or more years. These drugs often cause drug interactions with other medications (such as diuretics, anti-hypertensives, or cardiac medications), but also add more stress on the filtration process of the kidneys.( http://health.nytimes.com/health/guides/disease/analgesic-nephropathy/overview.html)

It is likely that patients with kidney problems with CHF complications will be prescribed diuretics to reduce fluid buildup in the lungs, as well as to encourage the kidneys to keep producing urine.

To prevent or control anemia patients may also be given iron supplements, or erythropoietin to stimulate red blood cell production. Patients with anemia may also need blood transfusions in addition to these drugs.

Dialysis: Hemodialysis and Peritoneal Dialysis

This treatment has been available since the 1940’s and extends the life of patients with End Stage Kidney Failure. Patients with kidneys that are highly damaged must have their blood detoxified by the dialysis machine because their kidneys can no longer do it themselves.

Hemodialysis
Patients must visit the dialysis clinic 3 to 4 times per week, for 3 to 4 hours at a time for this treatment. A catheter is placed into an artery where the blood is removed and filtered through a dialysis machine.A cleaning substance called dialysate is used to absorb toxins, salt, and water from the blood. The dialysate and the blood are separated by the machine and not mixed. One blood is fed into the machine the blood is detoxified and injected into a vein back into the body.

(http://www.merck.com/media/mmhe2/figures/MMHE_11_151666_01_eps.gif)

Peritoneal Dialysis
When toxins build up in the blood stream when kidneys cannot produce urine, excess water and toxins pass from the intestines into the abdominal cavity. This procedure involves a surgeon transplanting a Tenckhoff catheter into the peritoneal space of the abdomen near the pelvis. A tube exits the body and is capped off when not in use. This tube is attacked to a bag of dialysate where the toxins, salt, and water are removed.

Catheters should always be covered with a dressing to prevent exposure to infection. Dialysate is a substance high in sugar content which can promote bacterial growth.
http://www.ich.ucl.ac.uk/website/gosh/clinicalservices/Nephrology/MedicalConditions/Dialysis.pdf

Kidney Transplants

When the kidneys are severely damaged as in End Stage Renal Disease, the kidneys will eventually no longer be able filter blood or produce urine.

For any surgical procedure it is important to minimize the risk of infection. This is why transplant recipients do not have their sick kidneys removed. Instead, a third kidney is attached the abdominal aorta and inferioir vena cava.

A major barrier in the success of an organ transplant is rejection of the organ. This is why organ donation requires a rigorous blood typing process. Although even if a match is found, the recipient’s body maybe still recognize the donated organ as “foreign”— like a bacteria, or a virus—and trigger an immune response to attack it. This immune response could lead to rejection of the donated organ.

In order to prevent organ rejection immunosuppressant drugs are given to the patient. Some comment anti-rejection drugs are cyclosporine, prednisone, azathioprine, tacrolimus or FK506, mycophenolate mofetil, sirolimus, and OKT3, as well as ATGAM and Thymoglobulin.   

(http://medical-dictionary.thefreedictionary.com/Anti-Rejection+Drugs)

Side Effects:

Anytime immunosuppressors are given the body is left immunocompromised. Since the immune response is reduced to allow the transplanted kidney to not be rejected by the body, the body is esspecially suseptible to infection. If a bacteria enters the body, there will be less of a counter attack by the body’s defense system. The patient should be closely monitored and report any signs of fever or illness.

Anti-rejection Drug Contraindications:

According to the Free-Medical Dictionary, patients who are pregnant or breastfeeding should not take immunosuppressants. Also discouraged are the useage of antacids. These will diminish the effectiveness of the drugs. Patients taking cyclosporins should not eat grapefruit or grapefruit juice as it will cause free drug levels to increase.

(http://medical-dictionary.thefreedictionary.com/Anti-Rejection+Drugs)

Cost of Drug Therapy

The National Kidney Foundation has listed the cost of kidney treatments:
(http://www.kidney.org/news/newsroom/newsitem.cfm?id=135&&cid=105)

Kidney dialysis costs around $71,000 per year.
Kidney transplants costs $106,000 per transplant.
Immunosuppressant drugs cost around $10,000-$20,000 per year.

Persons under the age of 65 are being denied Medicare coverage for immunosuppressant drugs to suppress kidney rejection after 36 months of treatment. In May of this year, The Comprehensive Immunosuppressive Drug Coverage for Transplant Patients Act was introduced to extend coverage to this group to ensure that the drugs will be provided to ensure the health of their new kidney.