Hypoparathyroidism Flashcards
What is hypoparathyroidism?
Hypoparathyroidism is a low level of parathyroid hormone. Parathyroid hormone increases vitamin D-dependent calcium absorption, renal calcium reabsorption and renal phosphate clearance. Thus, in Hypoparathyroidism, patients get hypocalcaemia, hyperphosphatemia
Pseudohypoparathyroidism is characterised by similar findings but PTH is elevated due to PTH resistance.
What are the causes of hypoparathyroidism?
Common – Iatrogenic damage during surgery, Autoimmune
Others – Metal Overload (Haemochromatosis, Wilsons), Hypomagnesemia (Magnesium stimulates PTH release) Malignant Mets, Congenital, Idiopathic, Alcoholism, DiGeorges Syndrome (characteristic facies, congenital heart disease and hypocalcaemia)
What will you find on a history taking of hypoparathyroidism?
Symptoms: Caused by hypocalcaemia Tetany - Muscle Spasms Muscle cramps and bone pain Paraesthesia in fingertips, toes or perioral area Anxiety /Fatigue Poor memory/Slow thinking Cataracts Severe Hypocalcaemia - Laryngospasm causing stridor, Dystonia, Tachyarrhythmias (Prolonged QT interval), confusion, seizures, coma, confusion
Risk Factors:
Alcohol abuse
Specific Questions to ask:
Surgery to the neck
Family history
Differentials:
Magnesium deficiency - Differentiated by bloods
Vitamin D deficiency - Differentiated by bloods but common to have both
Chronic kidney disease - will have symptoms of CKD and risk factors
Pseudohypoparathyroidism (Resistance to thyroids hormones, but levels of PTH are normal or raised)
What will you find on examination of hypoparathyroidism?
End of the bed:
Tetany - Muscle Spasms
Dry skin.
Hands:
Positive Trousseau’s sign - hands contract when blood pressure cuff inflated above systolic for 3 mins
Hyperreflexia
Brittle nails with transverse grooves.
Neck:
Look for any neck scars indicating previous surgery
Face:
Positive Chvostek’s sign - Contraction of facial muscles on tapping facial nerve at the parotid
Cataracts – Reduced visual acuity
Raised intracranial pressure with papilledema.
Legs:
Hyperreflexia
What investigations will you order in hypoparathyroidism?
Bedside:
ECG - Look for prolonged QT or other arrhythmias
Full set of observations
Bloods:
PTH – Reduced (If raised then it is another cause of hypocalcaemia or pseudohypoparathyroidism)
Serum Calcium – Reduced
Serum Phosphate - Raised
Serum Magnesium - Magnesium deficiency exacerbates hypocalcaemia and impairs PTH secretion.
Serum 25-hydroxyvitamin D - Rule out vitamin D deficiency as the cause hypocalcaemia
Anti-Parathyroid antibodies – If autoimmune causes suspected
U&E – To rule out CKD (Another common cause of hypocalcaemia)
LFT – looking for any liver failure that could be as a result of Wilsons/Hemochromatosis/Alcohol Abuse
Serum Copper/Iron - Rule out Wilsons/Hemochromatosis
TSH - Rule out thyroid dysfunction
Adrenal and thyroid autoantibodies and TSH, ACTH if autoimmune hypoparathyroidism suspected to rule out other autoimmune conditions
What is the treatment of hypoparathyroidism
Resuscitation: Only if severe symptoms present
A-E approach
Get IV Access/Give O2 to maintain sats of 94+ /Attach 12 lead ECG
Assessment with AMPLE history and brief examination
Get help - Cardiology reg on call
Frequent Observations - Constant or 15 minutely
IV bolus of 10% calcium gluconate 10–20 mL with electrocardiogram monitoring followed by IV infusion if necessary.
Oral calcium and vitamin D as soon as possible. IV magnesium sulphate may also be required.
Lifestyle:
High Dairy diet – contain lots of calcium and vitamin D is recommended.
Medical:
Lifelong Vitamin D metabolites (calcitriol)) and oral calcium with regular monitoring to ensure adequate levels
