Which laboratory value would be affected if the parathyroid glands are removed during surgery

What is a Parathyroid Hormone (PTH) Test?

Definition:
PTH is a test that measures the amount of PTH (parathormone) in blood.

Inhaltsverzeichnis Show

What is a Parathyroid Hormone (PTH) Test?
View Sources
What happens if the parathyroid gland is removed?
Should all four parathyroid glands be examined before surgery?
What is a parathyroidectomy called?
How old do you have to be to have your parathyroid removed?
What would happen if the parathyroid glands were removed?
What would result from the total surgical removal of the parathyroid gland?
What should your calcium level be after parathyroid surgery?
What condition will occur if all parathyroid tissue is removed?

Alternative Names: Parathormone; Parathormone (PTH) intact molecule; Parathyroid hormone

How the test is performed:
Adult or child:

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to fill with blood. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. The tourniquet is then removed to restore circulation. After blood has been collected the needle is removed, and the puncture site is covered to stop any bleeding.

Infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. A bandage may be applied to the puncture site if there is any bleeding.

How to prepare for the test:
Fasting (except water) is required for 10 to 12 hours before the test.

How the test will feel:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed:
This test may be performed when PTH abnormality is suspected as a cause of abnormal calcium or phosphorus levels.

PTH, the most important regulator of body calcium and phosphorus, is a protein hormone secreted by the parathyroid gland.

PTH:

Increases calcium and phosphorus release from bone
Decreases the loss of calcium and increases the loss of phosphorus in the urine
Increases the activation of 25-hydroxy vitamin D to 1,25-dihydroxy vitamin D in the kidneys

Secretion of PTH is regulated by the level of calcium in the blood. Low serum calcium causes increased PTH to be secreted, whereas increased serum calcium inhibits PTH release.

Normal Values:
Normal values are 10-55 pg/mL. Normal value ranges may vary slightly among different laboratories.

Note: pg/mL = picograms per milliliter

What abnormal results mean:

Greater-than-normal levels may be associated with:

Chronic renal failure
Hyperparathyroidism
Malabsorption syndrome (inadequate absorption of nutrients in the intestinal tract)
Osteomalacia (adults)
Rickets (children)
Vitamin D deficiency
Pregnancy or breast feeding
Increased blood lipids
Medications such as rifampin, anticonsulsants, diuretics, lithium, and those containing phosphate

Lower-than-normal levels may be associated with:

Autoimmune destruction of parathyroid gland
Hypomagnesemia
Hypoparathyroidism
Metastatic bone tumor
Milk-alkali syndrome (excessive calcium ingestion)
Sarcoidosis
Vitamin D intoxication
Parathyroid glands that were accidentally removed in neck surgery

Additional conditions under which the test may be performed:

Multiple endocrine neoplasia (MEN) II
Multiple endocrine neoplasia (MEN) I
Secondary hyperparathyroidism

What the risks are:

Excessive bleeding
Fainting or feeling lightheaded
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Multiple punctures to locate veins

Special considerations:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

View Sources

Sources Used in Current Review

2017 review completed by Mahesheema Ali, MSc, PhD.

Gray, Christina E. Handbook of Diagnostic Endocrinology. Edited by I. Jiala, W. E. Winter and D. W. Chan, Clinical Chemistry and Laboratory Medicine (CCLM). DeepDyve. De Gruyter, 23 Oct. 2001.

McPherson, Richard A. Henry's Clinical Diagnosis and Management by Laboratory Methods. Edition 23.

Clarke, William. Contemporary Practice in Clinical Chemistry. Washington, DC: AACC, 2016. Print.

Carl A. Burtis, PhD and David E. Bruns, MD. Tietz Fundamentals of Clinical Chemistry. 6th Edition.

Sources Used in Previous Reviews

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Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

Spengler, R. (2001 April 3, Updated). Parathyroid Hormone. LaurusHealth.com, Medical Tests [On-line information]. Available online at http://www.laurushealth.com/library/healthguide/MedicalTests/topic.asp?HWID=hw8101.

(2002 march 3, Updated). PTH. Yahoo Health Encyclopedia [On-line information]. Available online at http://health.yahoo.com/health/encyclopedia/003690/0.html.

(2001 May 1, Updated). What Does The Parathyroid Do? Jewish Hospital HealthCare Services [On-line information]. Available online at http://jhhs.client.web-health.com/web-health/topics/GeneralHealth/generalhealthsub/generalhealth/endocrine/what_parathyroid.html.

Brown, T., Reviewed (2002 March 3). PTH. Pennhealth.com Health Illustrated Encyclopedia [On-line information]. Available online at http://www.pennhealth.com/ency/article/003690.htm.

(2001 May 13, Updated). Parathyroid Hormone. Colorado State University Hypertextbook, Pathophysiology of the Endocrine System [On-line information]. Available online at http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/thyroid/pth.html.

Parathyroid Hormone, Intact Molecule. ARUP's Guide to Clinical Laboratory Testing (CLT) [On-line test information]. Available online at http://www.aruplab.com/guides/clt/tests/clt_p3.htm.

Parathyroid hormone test. Hendrick Health System, AccessMed Health Information Library [On-line information]. Available online at http://www.ehendrick.org/healthy/00059880.html.

(2001). Parathyroid Hormone Decreases the Risk of Fractures in Postmenopausal Women with Osteoporosis. John Hopkins arthritis, archived news, 2001 archives [On-line news release]. Available online at http://www.hopkins-arthritis.som.jhmi.edu/news-archive/2001/pth.html.

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Gregory C. Sephel PhD FACB MT(ASCP). Lab Tests Online adjunct board member. Director Clinical Pathology, VA TN Valley Healthcare System; Associate Professor Pathology, Microbiology, Immunology, Vanderbilt University School of Medicine.

What happens if the parathyroid gland is removed?

The one or more parathyroid glands may be surgically removed in case of tumors of the glands. The removal of one or two parathyroid glands results in a condition called hypocalcemic tetany. It starts with a tingling sensation or numbness in your fingers or toes. There may be spasms of the muscles of the hands, causing wrist drop.

Should all four parathyroid glands be examined before surgery?

Parathyroid Surgery: All Four Parathyroid Glands Should Be Examined! Parathyroid Surgery: All Four Parathyroid Glands Should Be Examined! Because 30% of people with hyperparathyroidism will have more than one parathyroid tumor, the most successful parathyroid surgery only happens when surgeons examine all four parathyroid glands.

What is a parathyroidectomy called?

It’s also known as a parathyroidectomy. This surgery might be used if your blood has too much calcium in it. This is a condition known as hypercalcemia. Why do I need a parathyroid gland removal? Hypercalcemia occurs when blood calcium levels are abnormally high.

How old do you have to be to have your parathyroid removed?

The average age of diagnosis is around 65 years. You might also need parathyroid gland removal if you have: parathyroid hyperplasia, a condition in which all four of the parathyroid glands are enlarged. Calcium blood levels can rise even if only one gland is affected. Only one parathyroid gland is involved in about 80 to 85 percent of cases.

What would happen if the parathyroid glands were removed?

Only one half functioning parathyroid gland is needed for calcium control. If all four parathyroid glands were injured or removed during surgery, the blood calcium levels can become lower than normal.

What would result from the total surgical removal of the parathyroid gland?

What are the risks of parathyroidectomy?.

Persistent low blood calcium levels..

Voice changes, such as hoarseness..

Sore throat..

Bleeding and blood clots..

Adhesions or scar tissue requiring further surgery..

Injury to the esophagus or trachea (windpipe).

What should your calcium level be after parathyroid surgery?

For the surgery to be considered successful, their calcium level had to be below the upper level of normal laboratory levels (lower than 10.5 mg/dL) from 1 week after surgery (occasionally it takes a few days for the calcium to drop) and for at least 2 years postsurgery.

What condition will occur if all parathyroid tissue is removed?

Lifelong hypocalcemia: Damage to the healthy parathyroid glands while removing the diseased parathyroid gland may cause a permanent state of low blood calcium levels. You may have to take calcium supplements throughout your life.