Calcium Disorders Flashcards
What is the function of the Parathyroid hormone?
What regulates PTH production?
Maintain extracellular Calcium balance
Important in bone maintenance
Kidney acts thru gut (Vit D.)
Ionized Calcium concentration regulates the production of PTH
If Vitamin D is LOW; what may occur as a result? Why?
Osteoporosis
B/c Vit D is involved in Calcium transport from the gut; no Vit D –> no Calcium to regulate PTH production –> decreased bone resorption
34 yo female found to have a serum calcium of 11.1 mg/dl on routine blood work. Denies previous history of hypercalcemia, renal stones, ulcer disease. On no meds. Denies vitamin or supplement use. Told that her PTH level was normal.
Exam normal
HYPER-calcemia
Vit D intox
R/O MALIGNANCY!!!!! (myeloma, breast, lung, kidney MC)
Calcium is HIGH; but PTH is NORM
~~Primary Hyperparathyroidism
Adenoma (80%)
4 Gland hyperplasia (15%)
Cancer (<5%)
What are some potential causes of Hypercalcemia?
Immobilization Thiazide diuretics Vitamin A intox (Vit D intox) Renal failure Milk alkali syndrome or TUMS intox Addison's Dz Sarcoidosis Lithium Malignancy
What is the clinical picture of a PT with hypercalcemia presenting in your clinic?
Asymptomatic Fatigue & Depression Anorexia N/ V / Constipation Polyuria / stones Ulcer Dz Osteoporosis Fx
What is the Tx for Primary Hyperparathyroidism?
What is the criteria which will guide your Tx?
> 50% asymptomatic –> Tx is surgery
Use Criteria to decide if surgery implicated:
- Serum calcium >1.0mg/dL ABOVE NORM
- BMD T score < -2.5
- Age < 50 y/o
- Creatinine clearance < 60ml/min
- If periodic f/u is not reasonable
What is the appropriate Tx for Hypercalcemia in emergency management?
IV hydration NSS
Biphosphonates: Pamidronate
Zoledronic acid
Calcitonin
SteroidsWhat is a Chovstek sign?
Corner of the mouth twitches (common in normal as well though) Hit facial nerve lightly with reflex hammer
What is a Trousseau sign?
BP cuff inflated above systolic
Acidemic in the arm and PT will cramp up from
What are some causes of Hypocalcemia?
CRF
Hypoparathyroidism –> autoimmune
Vit D deficiency
Hypomagnesemia
Transient burns, transfusion, ARF, or pancreatitis
POSTOP NECK SURG (DID THEY TAKE IT OUT AND SHOULDNT HAVE)
What is the diagnostic criteria S/Sx of Hypocalcemia / what labs should you order for your suspected PT?
Spasms, convulsions, paresthesias Chvostek and/or Trousseau Sx Total and Ionized Ca2+ Serum albumin PTH Vit D Magnesium
What should the initial treatment be for a PT with a low calcium and high PTH?
50,000 IU weekly for 4-6 wks.
An elderly female with limited mobility is evaluated for fatigue, irritability, depression. Initial labs show normal renal function and TSH but low calcium and high alkaline phosphatase levels. What should be your next step?
Measure 25-hydroxyvitamin D level
An asymptomatic 48 y o male has a serum calcium of 11.6 mg/dL and PTH twice normal. No history of renal stones, bone fractures, or family history of hypercalcemia. What SHOULD the next step be in management?
IV pamidronate
