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If the underlying cause of the hypocalcemia can be addressed, the hyperparathyroidism will resolve. In people with chronic renal failure, treatment consists of dietary restriction of phosphorus, supplements with an active form of vitamin D such as calcitriol, doxercalciferol, paricalcitol, etc. and phosphate binders which can be divided into calcium-based and non-calcium based.
Extended Release Calcifediol was recently approved by the FDA as a treatment for secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 chronic �kidney disease (CKD) and low vitamin D blood levels (25-hydroxyvitamin D less than 30 ng/mL). It can help treat SHPT by increasing Vitamin D levels and lowering parathyroid hormone or PTH. It is �not for patients with stage 5 CKD or on dialysis.
In the treatment of secondary hyperparathyroidism due to chronic kidney disease on dialysis calcimimetics do not appear to affect the risk of early death. It does decrease the need for a parathyroidectomy but caused more issues with low blood calcium levels and vomiting.
Most people with hyperparathyroidism secondary to chronic kidney disease will improve after renal transplantation, but many will continue to have a degree of residual hyperparathyroidism (tertiary hyperparathyroidism) post-transplant with associated risk of bone loss, etc.
Treatment depends entirely on the type of hyperparathyroidism encountered.
In people with secondary hyperparathyroidism, the high PTH levels are an appropriate response to low calcium and treatment must be directed at the underlying cause of this (usually vitamin D deficiency or chronic kidney failure). If this is successful PTH levels should naturally return to normal levels unless PTH secretion has become autonomous (tertiary hyperparathyroidism)
Medications that are sometimes required include estrogen replacement therapy in postmenopausal women and bisphosphonates. Bisphosphonates may improve bone turnover.
Newer medications termed "calcimimetics" used in secondary hyperparathyroidism are now being used in primary hyperparathyroidism. Calcimimetics reduce the amount of parathyroid hormone released by the parathyroid glands. They are recommended in patients in whom surgery is inappropriate.
The surgical removal of one or more of the parathyroid glands is known as a parathyroidectomy; this operation was first performed in 1925. The symptoms of the disease, listed above, are indications for surgery. Surgery reduces all cause mortality as well as resolving symptoms. However, cardiovascular mortality is not significantly reduced.
The 2002 NIH Workshop on Asymptomatic Primary Hyperparathyroidism developed criteria for surgical intervention . The criteria were revised at the Third International Workshop on the Management of Asymptomatic Primary Hyperparathyroidism . These criteria were chosen on the basis of clinical experience and observational and clinical trial data as to which patients are more likely to have end-organ effects of primary hyperparathyroidism (nephrolithiasis, skeletal involvement), disease progression if surgery is deferred, and the most benefit from surgery. The panel emphasized the need for parathyroidectomy to be performed by surgeons who are highly experienced and skilled in the operation. The Third International Workshop guidelines concluded that surgery is indicated in asymptomatic patients who meet any one of the following conditions:
- Serum calcium concentration of 1.0 mg/dL (0.25 mmol/L) or more above the upper limit of normal
- Creatinine clearance that is reduced to <60 mL/min
- Bone density at the hip, lumbar spine, or distal radius that is more than 2.5 standard deviations below peak bone mass (T score <-2.5) and/or previous fragility fracture
- Age less than 50 years
Operative intervention can be delayed in patients over 50 years of age who are asymptomatic or minimally symptomatic and who have serum calcium concentrations <1.0 mg/dL (0.2 mmol/L) above the upper limit of normal, and in patients who are medically unfit for surgery
More recently, three randomized controlled trials have studied the role of surgery in patients with asymptomatic hyperparathyroidism. The largest study reported that surgery resulted in an increase in bone mass, but no improvement in quality of life after one to two years among patients in the following groups:
- Untreated, asymptomatic primary hyperparathyroidism
- Serum calcium between 2.60–2.85 mmol/liter (10.4–11.4 mg/dl)
- Age between 50 and 80 yr
- No medications interfering with Ca metabolism
- No hyperparathyroid bone disease
- No previous operation in the neck
- Creatinine level < 130 µmol/liter (<1.47 mg/dl)
Two other trials reported improvements in bone density and some improvement in quality of life with surgery.
If left untreated, the disease will progress to tertiary hyperparathyroidism, where correction of the underlying cause will not stop excess PTH secretion, i.e. parathyroid gland hypertrophy becomes irreversible. In contrast with secondary hyperparathyroidism, tertiary hyperparathyroidism is associated with hypercalcemia rather than hypocalcemia.
No treatment is generally required, as bone demineralisation and kidney stones are relatively uncommon in the condition.
Tertiary hyperparathyroidism is a state of excessive secretion of parathyroid hormone (PTH) after a long period of secondary hyperparathyroidism and resulting in a high blood calcium level. It reflects development of autonomous (unregulated) parathyroid function following a period of persistent parathyroid stimulation.
The basis of treatment is still prevention in chronic kidney failure, starting medication and dietary restrictions long before dialysis treatment is initiated. Cinacalcet has greatly reduced the number of patients who ultimately require surgery for secondary hyperparathyroidism; however, approximately 5% of patients do not respond to medical therapy.
When secondary hyperparathyroidism is corrected and the parathyroid glands remain hyperfunctioning, it becomes tertiary hyperparathyroidism. The treatment of choice is surgical removal of three and one half parathyroid glands.
Medical management of OFC consists of Vitamin D treatment, generally alfacalcidol or calcitriol, delivered intravenously. Studies have shown that in cases of OFC caused by either end-stage renal disease or primary hyperparathyoidism, this method is successful not only in treating underlying hyperparathyoidism, but also in causing the regression of brown tumors and other symptoms of OFC.
Almost all who undergo parathyroidectomy experience increased bone density and repair of the skeleton within weeks. Additionally, patients with OFC who have undergone parathyroidectomy begin to show regression of brown tumors within six months. Following parathyroidectomy, hypocalcaemia is common. This results from a combination of suppressed parathyroid glands due to prolonged hypercalcaemia, as well as the need for calcium and phosphate in the mineralization of new bone.
Thirty percent of patients with OFC caused by parathyroid carcinoma who undergo surgery see a local recurrence of symptoms. The post-surgical survival rate hovers around seven years, while patients who do not undergo surgery have a survival rate of around five years.
The goal of therapy is to treat the hypercalcaemia first and subsequently effort is directed to treat the underlying cause.
Initial therapy:
- hydration, increasing salt intake, and forced diuresis.
- hydration is needed because many patients are dehydrated due to vomiting or kidney defects in concentrating urine.
- increased salt intake also can increase body fluid volume as well as increasing urine sodium excretion, which further increases urinary potassium excretion.
- after rehydration, a loop diuretic such as furosemide can be given to permit continued large volume intravenous salt and water replacement while minimizing the risk of blood volume overload and pulmonary oedema. In addition, loop diuretics tend to depress calcium reabsorption by the kidney thereby helping to lower blood calcium levels
- can usually decrease serum calcium by 1–3 mg/dL within 24 hours
- caution must be taken to prevent potassium or magnesium depletion
Most cases of FHH are associated with loss of function mutations in the calcium-sensing receptor (CaSR) gene, expressed in parathyroid and kidney tissue. These mutations decrease the receptor's sensitivity to calcium, resulting in reduced receptor stimulation at normal serum calcium levels. As a result, inhibition of parathyroid hormone release does not occur until higher serum calcium levels are attained, creating a new equilibrium. This is the opposite of what happens with the CaSR sensitizer, cinacalcet. Functionally, parathyroid hormone (PTH) increases calcium resorption from the bone and increases phosphate excretion from the kidney which increases serum calcium and decreases serum phosphate. Individuals with FHH, however, typically have normal PTH levels, as normal calcium homeostasis is maintained, albeit at a higher equilibrium set point. As a consequence, these individuals are not at increased risk of the complications of hyperparathyroidism.
Another form has been associated with chromosome 3q.
Hypocalcemia is common and can occur unnoticed with no symptoms or, in severe cases, can have dramatic symptoms and be life-threatening. Hypocalcemia can be parathyroid related or vitamin D related. Parathyroid related hypocalcemia includes post-surgical hypoparathyroidism, inherited hypoparathyroidism, pseudohypoparathyroidism, and pseudo-pseudohypoparathyroidism. Post-surgical hypoparathyroidism is the most common form, and can be temporary (due to suppression of tissue after removal of a malfunctioning gland) or permanent, if all parathyroid tissue has been removed. Inherited hypoparathyroidism is rare and is due to a mutation in the calcium sensing receptor. Pseudohypoparathyroidism is maternally inherited and is categorized by hypocalcemia and hyperphosphatemia. Finally, pseudo-pseudohypoparathyroidism is paternally inherited. Patients display normal parathyroid hormone action in the kidney, but exhibit altered parathyroid hormone action in the bone.
Vitamin D related hypocalcemia may be associated with a lack of vitamin D in the diet, a lack of sufficient UV exposure, or disturbances in renal function. Low vitamin D in the body can lead to a lack of calcium absorption and secondary hyperparathyroidism (hypocalcemia and raised parathyroid hormone). Symptoms of hypocalcemia include numbness in fingers and toes, muscle cramps, irritability, impaired mental capacity and muscle twitching.
Treatment for renal osteodystrophy includes the following:
- calcium and/or native vitamin D supplementation
- restriction of dietary phosphate (especially inorganic phosphate contained in additives)
- phosphate binders such as calcium carbonate, calcium acetate, sevelamer hydrochloride or carbonate, lanthanum carbonate, sucroferric oxyhydroxide, ferric citrate among others
- active forms of vitamin D (calcitriol, alfacalcidol, paricalcitol, maxacalcitol, doxercalciferol, among others)
- cinacalcet
- renal transplantation
- haemodialysis five times a week is thought to be of benefit
- parathyroidectomy for symptomatic medication refractive end stage disease
High phosphate levels can be avoided with phosphate binders and dietary restriction of phosphate. If the kidneys are operating normally, a saline diuresis can be induced to renally eliminate the excess phosphate. In extreme cases, the blood can be filtered in a process called hemodialysis, removing the excess phosphate.
Disorders of calcium metabolism occur when the body has too little or too much calcium. The serum level of calcium is closely regulated within a fairly limited range in the human body. In a healthy physiology, extracellular calcium levels are maintained within a tight range through the actions of parathyroid hormone, vitamin D and the calcium sensing receptor. Disorders in calcium metabolism can lead to hypocalcemia, decreased plasma levels of calcium or hypercalcemia, elevated plasma calcium levels.
Parathyroid auto transplantation is part of the treatment when a patient has hyperparathyroidism and three or four parathyroid glands were already removed, but during the surgery one of the glands (in the case of the removal of three) is relocated at another part of the body to make, the procedure less risky another procedure. In the case of complete parathyroidectomy, a half gland is cryopreserved. In case the patient suffers hypoparathyroidism. If this happens the extracted parathyroid is relocated to another place of the body for example the forearm. Parathyroid auto transplantation begins with parathyroid tissue extraction, which must be preserved into a cold isotonic solution until the patient needs it. Research has shown that parathyroid tissue can function at subcutaneous level until the transplantation. If this is not possible, the most common procedure is to create a small pocket of muscle, tissue at least 2 cm deep by separating the muscular fibers. Then the parathyroid tissue is placed into and closed by suturing the area. After the extraction the tissue might be processed at the laboratory, as soon as possible. Once at the laboratory the tissue sample is placed at a frozen petri dish where it is cut into small pieces (approximately 1–2 mm). The small pieces are placed into test tubes and filled with a solution in three parts one at 20% of autologous serum (about 0.6 ml) and the other part of isotonic solution at 20% (about 0.6 ml) then a solution of 2 ml of polypropylene and mixed gently. Then is placed into a container at -70 °C for a night then finally the container passes through the phase of liquid or vapor nitrogen immersion and is kept there until needed. When it is needed the sample is taken out of the nitrogen and placed into a bath of water at 37 °C until the ice is melted almost completely except for the samples core. Then 0.5 ml of the melted solution is removed and replaced for fresh isotonic solution.
The single major disease of parathyroid glands is overactivity of one or more of the parathyroid lobes, which make too much parathyroid hormone, causing a potentially serious calcium imbalance. This is called hyperparathyroidism; it leads to hypercalcemia, kidney stones, osteoporosis, and various other symptoms. Hyperparathyroidism was first described in 1925 and the symptoms have collectively become known as "moans, groans, stones, and bones." By far, the most common symptom is fatigue, but depression, memory loss, and bone aches are also very common. Primary hyperparathyroidism is relatively more common in postmenopausal women. The primary treatment for this disease is the surgical removal of the faulty gland.
If a patient has elevated calcium, several different types of tests can be used to locate the abnormal glands. The most common and most accurate test to find a parathyroid tumor is the Sestamibi scan. The Sestamibi scan does not have high resolution. Neck ultrasound has higher resolution, but requires some expertise to perform. Ultrasound's shortcomings include: it cannot determine glandular function (normal vs. hyperfunctioning) or visualize unusual locations such as retropharyngeal or mediastinal. Thin cut computed tomography of the neck can reveal glands in locations that the ultrasound cannot evaluate well; e.g. retropharyngeal, mediastinal. These tests are ordered by an endocrinologist or a surgeon that specializes in parathyroid surgery. Often, these "localizing" tests used to "find" the bad parathyroid gland are not successful in locating which parathyroid gland has become a tumor. This often causes confusion for the patient and doctor, since the tumor was not located. This simply means that the tumor was not found using these tests; it does not mean the tumor does not exist. The use of ultrasound-guided FNA, and parathyroid hormone washings can confirm the abnormal glands. For decades, it has been known that the best way to find a parathyroid tumor is through a very experienced parathyroid surgeon.
Even if a patient has a non-localizing Sestamibi scan (a negative sestamibi scan), he/she should almost always have a neck exploration to remove the tumor if he/she has high calcium levels, among other symptoms. Minimally-invasive parathyroid surgery is becoming more available, but, depending on the expertise of the surgeon, the patient may need to have a positive sestamibi scan before a minimally-invasive operation is attempted. Some of the most experienced surgeons perform mini-parathyroid surgery on all patients, but this is available only at highly specialized centers. Some patients will need both sides of their necks explored to find the dysfunctional gland(s).
Another related condition is called secondary hyperparathyroidism (HPT for short), which is common in patients with chronic kidney disease on dialysis. In secondary HPT, the parathyroid glands make too much parathyroid hormone (PTH) because the kidneys have failed, and the calcium and phosphorus are out of balance. Even though one may not have any symptoms, treating secondary HPT is important. Cinacalcet (Sensipar) is a medicine that can help treat such dialysis patients and is available by prescription only. Most experts believe that Sensipar should not be used for patients with primary hyperparathyroidism (patients that have a high calcium and are not on kidney dialysis).
Parathyroid surgery is usually performed when there is hyperparathyroidism. This condition causes many diseases related with calcium reabsorption, because the principal function of the parathyroid hormone is to regulate it. Parathyroid surgery could be performed in two different ways: first is a complete parathyroidectomy, and second is the auto transplantation of the removed parathyroid glands. There are various conditions that can indicate the need for the removal or transplant of the parathyroid glands. Hyperparathyroidism is a condition caused by overproduction of PTH, and can be divided into three types.
- Primary hyperparathyroidism happens when the normal mechanism of regulation by negative feedback of calcium is interrupted, or in other words the amount of blood calcium would ordinarily signal less production of PTH. Most of the time this is caused by adenomas, hyperplasia or carcinomas.
- Secondary hyperparathyroidism normally occurs in patients that suffer renal disease. Poor kidney function leads to a mineral disequilibrium that causes the glands hypertrophy in order to synthesize and release more PTH.
- Tertiary hyperparathyroidism develops when the hyperplastic gland of secondary hyperparathyroidism constantly releases PTH, independent of the regulation systems.
Another condition is hypercalcemia, which refers to a calcium level above 10.5 mg/dL. Consequences of this are heart rhythm diseases, and extra production of gastrin that causes peptic ulcers.
Parathyroid transplant is recommended if the parathyroid glands are removed accidentally during a thyroidectomy. They are autotransplanted to the nearby sternocleidomastoid muscle, or to the forearm so that another intervention would be less risky. A biopsy is recommended to be sure that the transplanted tissue is parathyroid and not a lymph node with metastatic disease. During parathyroid surgery if there is an adenoma the transplantation is not recommended; instead it is cryopreserved for research an if there is a recurrent hypoparathyroidism.
The surgery is indicated for all patients that are diagnosed with hyperparathyroidism with or without symptoms, especially in younger patients. In some cases the surgery works as therapy for nephrolithiasis, bone changes, and neuromuscular symptoms.
Recovery from renal osteodystrophy has been observed following kidney transplantation. Renal osteodystrophy is a chronic condition with a conventional hemodialysis schedule. Nevertheless, it is important to consider that the broader concept of CKD-MBD, which includes renal osteodystrophy, is not only associated with bone disease and increased risk of fractures but also with cardiovascular calcification, poor quality of life and increased morbidity and mortality in CKD patients (the so-called bone-vascular axis). Actually, bone may now be considered a new endocrine organ at the heart of CKD-MBD.
The name "milk-alkali syndrome" derives from a reaction that arose to a treatment for gastric ulcers created in the early 1900s by Bertrand Sippy; Sippy prescribed his patients milk and alkali on the theory that ulcers were caused by excessive gastric acid. However within a few decades, an acute hypercalcemia syndrome with a relative good outcome was identified by Cuthbert Cope in 1936 (now called Cope syndrome), and in 1949 Charles H. Burnett identified a similar but more severe syndrome, with chronically high blood calcium levels and poor outcomes.
When the true cause of most gastric ulcers was identified and drugs other than antacids were developed to treat heartburn - namely acid-reducing drugs like H2-receptor antagonists or proton pump inhibitors - the incidence of milk-alkali syndrome greatly diminished. However, as a result of increased osteoporosis awareness and the routine use of calcium supplements to prevent it, the incidence has again increased.
Treatment involves having the person stop taking any calcium supplements and any other alkali agents they have been taking, and hydration.
In severe cases, hospitalization may be required, in which case saline may be administered intravenously.
If kidney failure is advanced then treatment for that is required, namely chronic dialysis.
Surgery is the only cure for parathyroid adenomas. It is successful about 95% of the time. Parathyroidectomy is the removal of the affected gland(s). The standard of treatment of primary hyperparathyroidism was formerly a surgical technique called bilateral neck exploration, in which the neck was opened on both sides, the parathyroids were identified, and the affected tissue was removed. By the 1980s, unilateral exploration became more common. Parathyroidectomy can now be performed in a minimally invasive fashion, mainly because imaging techniques can pinpoint the location of the tissue. Minimally invasive techniques include smaller open procedures, radio-guided and video-assisted procedures, and totally endoscopic surgery.
Before surgery is attempted, the affected glandular tissue must be located. Though the parathyroid glands are usually located on the back of the thyroid, their position is variable. Some people have one or more parathyroid glands elsewhere in the neck anatomy or in the chest. About 10% of parathyroid adenomas are ectopic, located not along the back of the thyroid but elsewhere in the body, sometimes in the mediastinum of the chest. This can make them difficult to locate, so various imaging techniques are used, such as the sestamibi scan, single-photon emission computed tomography (SPECT), ultrasound, MRI, and CT scans. sometimes parathyroid adenomas can be ablated by ethanol injection, guided by ultrasound.
Metastatic calcification is deposition of calcium salts in otherwise normal tissue, because of elevated serum levels of calcium, which can occur because of deranged metabolism as well as increased absorption or decreased excretion of calcium and related minerals, as seen in hyperparathyroidism.
In contrast, dystrophic calcification is caused by abnormalities or degeneration of tissues resulting in mineral deposition, though blood levels of calcium remain normal. These differences in pathology also mean that metastatic calcification is often found in many tissues throughout a person or animal, whereas dystrophic calcification is localized.
Metastatic calcification can occur widely throughout the body but principally affects the interstitial tissues of the vasculature, kidneys, lungs, and gastric mucosa. For the latter three, acid secretions or rapid changes in pH levels contribute to the formation of salts.
Signs and symptoms include ectopic calcification, secondary hyperparathyroidism, and renal osteodystrophy. Abnormalities in phosphate metabolism such as hyperphosphatemia are included in the definition of the new chronic kidney disease-mineral and bone disorder (CKD-MBD).