Clin Med - Parathyroid Disorders.pdf

Parathyroid Disorders ASHLEY NORDAN, MHPE, MSCR, MPAP, PA-C CAMPBELL PA PROGRAM The Basics: Anatomy  Located on the posterior surface of the thyroid.  Most people have 4 (2 on each lobe) but may have as few as 2 or as many as 6. The Basics: Physiology  PTH is secreted by parathyroid chief cells i...

Parathyroid Disorders ASHLEY NORDAN, MHPE, MSCR, MPAP, PA-C CAMPBELL PA PROGRAM The Basics: Anatomy  Located on the posterior surface of the thyroid.  Most people have 4 (2 on each lobe) but may have as few as 2 or as many as 6. The Basics: Physiology  PTH is secreted by parathyroid chief cells into the blood stream is response to decreased blood calcium levels.  PTH stimulates osteoclasts to resorb bone and release calcium into the bloodstream  PTH increases rental tubular reabsorption of calcium and stimulates calcitriol synthesis from calcidiol in response to increased Ca2+ in the kidney  PTH also increases renal excretion of phosphate  Calcitriol promotes calcium absorption in the small intestines Lets first discuss Calcium… Calcium  Normal range: 8.5-10.2 mg/dL  1st step is to verify abnormal calcium   Total calcium corrected for albumin  Hyperalbuminemia – dehydration, Multiple Myeloma  Hypoalbuminemia – Chronic illness, malnutrition Ionized (free) calcium Corrected calcium = serum calcium mg/dL +(0.8 x [4.0 – serum albumin g/dL]) Pop Quiz! What is the most common cause of Vitamin D deficiency? Hypercalcemia Presentation  Nephrolithiasis  Bone Pain (Osteitis fibrosa cystica)  Constipation; N/V  Weakness  Lethargy  Stupor  Coma “Stones, Bones, Abdominal Groans, & Psychiatric Overtones” Hypocalcemia Presentation Acute  Paresthesias (perioral, hands, feet)  Increased Muscle Spasticity  Chronic  Extrapyramidal symptoms:  Akathisia  Chvostek sign – facial spasm to rub  Dystonia  Trousseau sign – carpal spasm during BP  Tardive dyskinesia Cardiac Involvement  Heart failure  Prolonged QT  Parkinsonism  Dementia  Cataracts  Poor Dentition  Dry skin Now lets talk about what causes abnormal calcium levels Hyperparathyroidism The Basics  1º Hyperparathyroidism   2º Hyperparathyroidism   Problem with the parathyroid glands themselves Problem with the end organ (bone or kidneys) 3º Hyperparathyroidism  Chronic stimulation of the parathyroid glands causing hypertrophy and ultimately autonomous overproduction of PTH Primary Hyperparathyroidism  Most common cause of hypercalcemia**  Epidemiology   Most common in African Americans, Women , 7th decade of life Etiology  Parathyroid adenoma (~80%)  Gland hyperplasia (~20%)  Carcinoma (~1%) Primary Hyperparathyroidism  Clinical Presentation: “stones, bones, abdominal groans, psychiatric overtones”  Diagnosis:  Calcium – elevated  PTH – elevated  Vitamin D – normal or elevated  Phosphorous – normal or low Primary Hyperparathyroidism  Treatment:   Parathyroidectomy  Refer to surgery in all symptomatic patients or if calcium is >1 above ULN  Consider referral for asymptomatic patients 7.5 Summary  Always correct calcium first.  Determine PTH mediated or not  PTH and vitamin D levels  Other labs such as magnesium, phosphate as appropriate  Primary hyperparathyroidism   Hypoparathyroidism  determine observation versus surgery adequate supplementation of Ca and Vit D Corrected Calcium LOW HIGH PTH PTH LOW 1º Hypoparathyroidism High or really low Mg HIGH LOW HIGH 2º Hypoparathyroidism Malignancy Vit D intoxication 2º Hyperparathyroidism CKD, Vit D def 3º Hyperparathyroidism Longstanding CKD, Vit D def Pseudohypoparathyroidism 1º Hyperparathyroidism Questions? Resources  Andreoli, Thomas E., and Russell L. Cecil. Cecil Essentials of Medicine. 8th ed., W. B. Saunders Company, 2010.  Cho KC. Electrolyte & Acid-Base Disorders. In: Papadakis MA, McPhee SJ, Rabow MW. eds. Current Medical Diagnosis & Treatment 2019 New York, NY: McGraw-Hill;. http:// accessmedicine.mhmedical.com.proxy.campbell.edu/content.aspx?bookid=2449&sectionid=194574266. Accessed March 13, 2019.  Diaz, Dawn. “Parathyroid disorders”. 2018  Fuleihan, G.E & Silverberg, S.J. (2017). Primary Hyperparathyroidism: Clinical manifestations. In C.J. Rosen & J.E. Mulder (Eds.), UpToDate. Available from: https://www-uptodate-com.libproxy.lib.unc.edu/contents/primaryhyperparathyroidism-clinical-manifestations? search=hyperparathyroidism&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3  Shane, E. (2018). Diagnostic approach to hypercalcemia. In C.J. Rosen & J.E. Mulder (Eds.), UpToDate. Available from: https://www-uptodate-com.libproxy.lib.unc.edu/contents/diagnostic-approach-to-hypercalcemia? search=hypercalcemia&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H4