Bone Disease in Dialysis Patients
Bone disease in dialysis patients mainly "Secondary Hyperparathyroidism" called "Parathormone" is caused by a disease characterized by elevation. Yet, the early phase of chronic renal failure (pre-dialysis), even in the present case in many patients.
Called hyperparathyroidism causes of disease;
1. A low blood level of calcium element
2. The lack of vitamin D in the body
3. The height of phosphorus in the blood.
Lack of vitamin D; useful in the body that is created by a release of the active form of vitamin kidney enzyme. Kidney failure can not occur until enough of this enzyme reduces the amount of vitamin D in the blood.
A high blood phosphorus; called parathyroid hormone and parathyroid hormone increases the amount of blood from the blood by stimulating the parathyroid glands that secrete directly.
The low blood calcium; PTH suppressive effect on the reduction of calcium and thus causes increased parathormone.
In conclusion; is chronically low blood calcium levels causes blood levels of vitamin D is low and the high blood phosphorus levels parathyroid gland to grow to several times its original size. Normally, the larger the higher levels also increase the amount of blood parathyroid hormone secreted by the parathyroid glands, the "Secondary Hyperparathyroidism" called and led to a number of diseases that cause bone destruction.
Another bone diseases "to aluminum-induced bone disease" is. High blood levels of aluminum causes a toxic effect on the bone.
Rise in blood aluminum levels, from the dialysate water, or aluminum-containing phosphate binders drugs (whether pistachios, alujel) stems from the use of very long time.
Aluminium-induced bone disease, today, is infrequent use of phosphate binders containing aluminum because of improvement in the reduction of drug and standard dialysate water treatment.
Symptoms of Bone Diseases:
Bone disease in dialysis patients with mild and moderate or may not be any symptoms.
1. hyperparathyroidism due to bone disease: The most prominent complaints; bone pain, joint discomfort, and itching. "Metastatic calcification called" blood calcium and phosphorus around the joints due to the high amount of calcium-phosphorus complex crash (arthritis), acute arthritis, can cause pain and limited motion.
2. Aluminum-dependent bone disease: has led to more severe bone pain and limitation of movement in this disease. Mostly seen in the ribs, but can also be seen in other bone fractures are not uncommon. Other symptoms of aluminum poisoning, anemia (anemia), and central nervous system involvement are the symptoms depends on the (stuttering, hard speech disorders, muscle recessions, seizures, personality changes, dementia, etc.).
Laboratory findings of bone disease:
1. hyperparathyroidism due to bone disease:
a) Alkaline phosphatase: alkaline substance is an enzyme called secreted phosphatase from bone and other tissues. Bone Alkaline Phosphatase sourced always rises., Sometimes reaching up to 10 times the upper limit of normal (normal range: 45-130). In addition to bone alkaline phosphatase; Liver (the most important source), is secreted from the intestine and kidney. Therefore, blood alkaline phosphatase increased level of liver enzymes before being told that the induced bone (SGOT, SGPT) values should be shown to be normal and should be investigated whether intestinal origin.
b) Calcium: Blood calcium levels are usually normal or slightly lower. In advanced disease Hyperparathyroidism due to the growth of the parathyroid glands, hypercalcemia (increased blood calcium levels) may occur, but is usually mild 12 mg / dlt (3 mmol) does not exceed one (of normal: 8.5 to 10.2 mg / DLT). Elevation of blood calcium, calcium-containing phosphate binders drugs (Phos-ex, calcium carbonate) or vitamin D therapy (Calcijex, Alpha One, Alpha D3, Rocaltrol) during the develop.
c) Phosphorus: blood phosphorus levels are usually elevated in the predialysis period and often 6-7 mg / dlt (2-3 mmol) (Nora-up:) or higher. Although phosphorus, parathyroid hormone and blood phosphorus level elevation even though interrelated alone does not mean that there is a serious bone disease.
d) Parathormone: Blood parathyroid hormone values are almost always very high. (Of normal: 10-65 pg / milliliter, normal values in dialysis patients: 100-150 pg / milliliter). 250-300 pg / higher values than mlt' suggest the presence of hyperparathyroidism. 1000 pg / mlt'y exceeding values are seen in patients with severe hyperparathyroidism and parathyroid glands, which suggests significant growth.
2. Aluminum-dependent bone disease: Laboratory findings partly depends on the level of the disease.
a) Alkaline phosphatase and parathyroid hormone: aluminum accumulation of aluminum toxicity in patients on long-term causes of hyperparathyroidism due to a decline in bone disease. In this case the blood bone alkaline phosphatase and parathyroid hormone levels are normal or only slightly elevated.
b) Calcium aluminum-induced bone disease in blood calcium levels tend to be normal.
c) Blood levels of aluminum serum aluminum levels in patients who are not on dialysis normally 2 microg / is less than LT. In the majority of dialysis patients, this value 10-60 mg / l varies. The relationship between these general boundaries in the serum aluminum levels and the degree of aluminum accumulation in advance so unpredictable. Today in dialysis patients 30 mg / liter threshold serum aluminum levels is a reliable index for determining the loading of aluminum.
Radiological findings of bone disease:
1. hyperparathyroidism due to bone disease: mild form is usually no radiological findings, but there is always a serious disease. Hyperparathyroidism will be examined to determine the most reliable of the hands. Also skull and long bones in the symptoms seen radiographically.
2. Aluminum-dependent bone disease: rib fractures are common, especially in children, rickets seen.
Bone Disease Prevention and Treatment:
Basis for the prevention of bone disease in dialysis patients, the degree of disease called hyperparathyroidism is based on minimizing and reducing the amount of bone aluminum deposition.
A. Hyperparathyroidism: To prevent hyperparathyroidism in dialysis patients, to raise blood calcium levels, you need to lower the blood phosphorus levels and keep blood parathyroid hormone level between the desired value. For this purpose, phosphorus binding drugs that calcium supplements and vitamin D therapy in the treatment applied.
1. Calcium supplementation: Dialysis patients often 500 mg / day, or in a negative calcium balance may take less calcium. In addition, serum calcium levels may be decreased due to reduced vitamin D absorption from the intestine. resort; calcium carbonate to prevent low blood calcium levels (powder) and calcium acetate (Phos-ex) oral calcium to form calcium concentrations and the dialysis solution is to keep an adequate level. If the only goal is to increase blood calcium levels, calcium supplements should be taken between meals or at night.
2. the control of serum phosphorus levels are important for several reasons the control of serum phosphorus levels.
a) If the serum calcium level of about 10 mg / if dlt'lik will be at a level maintenance desirably, the increase of high blood phosphorus level of calcium-phosphorus product and thus causes the calcified various locations of the body. This causes an unwanted pathology called metastatic calcification.
b) High blood phosphorus concentrations, lowers blood ionized calcium levels, which increases the amount of blood parathyroid hormone stimulates the secretion of parathyroid hormone.
c) High blood phosphorus concentrations disrupts the synthesis of vitamin D in the body.
d) increased to reduce high blood phosphorus concentrations can reduce the amount of serum parathyroid hormone and prevent the growth of the parathyroid glands.
Desired values for the blood phosphorus levels 4 to 5.5 mg / dlt (1.3-1.8 mmol) d.
During hemodialysis, typically about 2.5 g of phosphorus removed or 800 mg per week in each session. Extending the duration of dialysis are important, but the benefits are limited. Usually during dialysis serum phosphorus levels fall rapidly, so that the phosphorus gradient decreases and the removal of phosphorus from the dialyzer during dialysis prevented.
Daily intake of phosphorus is very closely linked to the protein intake. Especially foods rich in phosphorus; Dairy products (milk, yogurt, cheese), liver, meat, legumes, nuts, cereals and breads made from them, a lot of non-alcoholic drinks (especially colas). Daily phosphorus intake of 800 mg / day, or about 5.6 g / week under the download is impossible. Then, if the use of phosphate binders drug if it is desired to check phosphorus level is required. This does not mean you should not be restricted phosphorus.
Phosphorus binders allow for the absorption of 50% of the obtained phosphor. If not limiting phosphorus intake (e.g., 1.4 g / day), 9.8 g per week. Phosphorus would be taken. Although only 50% even after connecting to absorb phosphorus, dialyzed to 4.9 g per week. Or 1.6 g of each dialysis. Phosphorus removal is required, which is twice the usual loss of phosphorus. Resulting in serious blood phosphorus level height (hyperphosphatemia) can occur.
3. Phosphorus binding drugs:
a) calcium-containing drugs (Phos-ex, calcium carbonate powder): Initially, calcium-containing phosphate binders should be used in all patients. They meet the calcium needs. Calcium, to extract the maximum extent of binding phosphorus should be proportional to the amount of food taken and phosphorus. Taken with meals reduces the absorption of calcium, but only the amount of calcium absorbed are still significant. Often enough, sometimes it is too much. If the amount is too high dialysate calcium concentration should be reduced. The dose required the use of calcium-containing phosphate binders drugs is varied and determined by the physician specifically for each patient. Sensation of gas and abdominal discomfort can occur as undesired side effects.
b) the Sevalam (Renagel) is a new drug without calcium and aluminum. Is well tolerated. The biggest advantage of calcium-containing phosphate binders drugs caused hypercalcemia (elevated blood calcium levels of) is to bear the risk. It is also one of the beneficial effects of lowering blood fat lightly. The dose of the drug is set by the condition of the patient by the physician for each patient.
c) Aluminium Containing Drugs (Carafate, Alujel): In general, the aluminum-containing phosphate binders should be avoided in patients on dialysis. However, it believes that the use of these drugs is necessary in some circumstances are clinicians. In patients with severe hyperparathyroidism and high calcium-phosphorus product, until it is put under control serum phosphorus levels of vitamin D therapy should not be administered. If dialysate calcium level is low, you may be able to give the calcium-containing phosphate binders drugs. In such patients, alternatively, the phosphorus-containing aluminum coupling agents mentioned. Short-term adverse effects in the central nervous system or creating use of these drugs on bone, but also citrate intake (fruit juices, Alka-Seltzer) if it is not, it is unlikely. When an aluminum-containing phosphate binders drug use is considered a superior option to apply it Renagel.
d) Calcium, the mixture of compounds containing aluminum or magnesium: Sometimes, such a mixture can be tailored to the patient allows the control of serum phosphorus levels.
4- Vitamin D Therapy: The beneficial effects of vitamin D in uremic bone disease;
a-) Adequate intake of vitamin D increases calcium absorption from the intestine and increases blood calcium,
b) vitamin D treatment inhibits the release of parathyroid hormone also increases the sensitivity of the parathyroid gland calcium suppressive effect. In both cases allows an improvement in the reduction of blood levels of parathyroid hormone and bone diseases,
c) uremia useful on bone mineralization has been claimed to be a direct effect of vitamin D, but it is arguably the presence of such an effect.
If you were an early start of dialysis and calcium-containing phosphate binders to use drugs than we initially started, some clinicians routinely initially not use vitamin D. If this strategy is applied, both the level of parathyroid hormone, serum calcium levels should be monitored regularly.
If blood calcium levels 9-10 mg / dLT or parathyroid hormone level is not maintained at the level of 250 pg / if mlt'y exceeds vitamin D therapy should be initiated.
Some clinicians begin at the start of dialysis, or even as an alternative to vitamin D treatment during the course of chronic renal failure. The logic is to take advantage of the suppressive effect of vitamin D on the parathyroid hormone.
Vitamin D therapy improves the absorption of phosphorus from the intestine and stimulates the blood phosphorus levels (hyperphosphatemia) may aggravate. Also increases the absorption of calcium from the intestine and vitamin D treatment with calcium acetate (Phos-ex) or calcium carbonate (powder) often use blood calcium level rise (hypercalcemia) causes.
The goal of vitamin D treatment, serum parathormone levels of 150-200 pg / mlt'y should be to download. Normal to the (10-60 pg / milliliter) download attempt called adynamic bone disease can lead to another disorder.
5-parathyroidectomy (surgical removal of the parathyroid glands): The fall of blood parathyroid hormone levels despite high doses of intravenous vitamin D therapy, suggesting the presence of a large parathyroid glands should be removed. Severe hyperparathyroidism calcium-phosphorus product of prolonged medical treatment constitutes a risk to rise to dangerous limits, this also increases the risk of metastatic calcification being called to the collapse of tissue potassium.
Therefore, if severe, hyperparathyroidism, parathyroid tissue has to be removed by surgery.