Hypoparathyroidism Flashcards
D?
A relative or absolute deficiency of parathyroid hormone as there is either a lack of synthesis of a lack of secretion.
RF?
- Thyroid surgery
- Parathyroid surgery
- Hypomagnesaemia
- Mod and chronic maternal hypercalcaemia
- AD conditions
ddx?
• Hypovitaminosis D-high PTH
• Hypomagnesaemia-
• Hypoalbuminemia
• Pseudohypoparathyroidism-
• end-organ (i.e., bones andkidneys) resistance toparathyroid hormone(PTH) despite sufficientPTHsynthesis due to adefectiveGsproteinalpha subunit
• Pseudopseudohypoparathyroidism-extremely rare condition that mimicsPHP type 1abut withoutend-organresistance toPTH
Renal failure/CKD-high creatinine
Aetiology?
- Post-op injury
- Autoimmune
- Congenital
- Infiltration-(Wilson’s disease,hemochromatosis,granulomas,metastases)
- Radiation-induced destruction
- Gram-negative sepsis
- Toxic shock syndrome
- HIV infection
CP?
- Symptoms of hypocalcaemia
- Chvostek sign-hyperexcitable nerves and contraction of facial muscles
- Trousseau-Occlusion of brachial artery with BP cuff causes carpal spasm
- Extrapyramidal disorders
- Ocular disease
- Skeletal-increases density and osteosclerosis
- Dental-hypoplasia
- Cutaneous-dry puffy coarse skin
Pathophysiology?
• Damage to glands in neck surgery or radiation therapy/infection
• In infiltration, compounds like excess copper, iron , fibrous tissue and cancerous cells are deposited here which cause destruction and dysfunction of the parathyroid gland.
• If there is low calcium, PTH cannot be secreted to increase vitamin D levels and absorption, so either vitamin D takes over or there is a lack of calcium and phosphate and magnesium as they are co-transported.
• It also means that there is less free calcium in the blood.
However, if there is somehow a build up of calcium, there is no NF to reduce PTH and so reduce increases in calcium-depositions with medications or exogenous sources.
I-first line?
• Serum calcium-low • Serum albumin-normal • ECG-Prolonged QT • Plasma PTH-low or normal • Serum magnesium-low • Serum vitD-low • Serum phosphorus-high • Serum creatinine-normal • 24-hr urine tests-low FBC-exclude anaemia
I-second line?
Excluding pathologies/causes-imaging, eye and ear exams, other electrolytes and hormones
M-severe?
• IV calcium gluconate
• Parenteral Magnesium sulphate
• Treat for resp alkalosis-
• Alkalosis can reduce the ionised fraction of serum calcium by favoring calcium binding to albumin
Symptomatic-oral calcium or low dose calcitriol
M-ongoing?
• Oral calcium plus calcitriol-after surgery
• PTH
• Thiazide-hypercalciuria
• Oral magnesium
Treat underlying condition-autoimmune polyendocrine syndrome 1, coeliac disease or drugs.
P?
• Good prognosis if after surgery, damaged take longer ot recover
Hard to manage calcium levels in permanent
C?
• Ectopic calcifications • Cataract • Hypercalcaemia • Renal insufficiency Renal stones