Hypocalcemia Flashcards
What are the symptoms of hypoCa?
- Spasms & Trousseau’s sign
- Chvostek’s sign
- Perioral paraesthesia
- Seizures
- Cardiomyopathy: ECG Changes – QTc Prolongation 🡪 TORSADE DE POINTES
- Neuromuscular Symptoms: Tetany, Fasciculations
- Anxious, irritable, irrational
- Muscle tone increased (colic, wheeze, dysphagia, stridor)
- Orientation impaired (TPP), confusion
- Dermatitis
- Impetigo herpetiformis
- Choreoathetosis
- Cataract
How will hypoCa appear on CT scan?
Basal Ganglia Calcification
What are risk factors to screen for hypoCa?
- Family history of low calcium (makes genetic conditions more likely)
- Recent neck surgery/ RT/ thyroidectomy/ parathyroidectomy
- Renal disease / CKD
What to examine in a patient with hypoCa?
Confirming the low Calcium state:
- Tetany (remember: HypoMg and HypoCa causes tetany)
- Trousseau’s sign (hand)
- Chvostek’s sign (facial nerve)
Looking for clues to etiology
- Neck scars, radiation marks
- Mucocutaneous Candidiasis
Albright’s hereditary osteodystrophy
- Causes pseudohypoparathyroidism type 1a aka PTH resistance 🡪 causing ____________
- Includes ______, short stature, short _____________, obesity, subcutaneous calcifications, and ___________
- Send for karyotyping
Management: provide ____________ (b/c PTH is impt in Vit D synthesis, hence pt will have low Vit D Calcitriol)
HypoCa and high PTH
round facies;
fourth metacarpal & metatarsal bones
developmental delay (Low IQ);
BOTH Calcium & Activated Vitamin D
What is Trosseau sign?
A blood pressure calf is inflated to 20mmHg above systolic bp
Arterial blood flow to the hand is occluded for 3-5min
Carpopedal spasm
- flexion at the wrist
- flexion at the MCP joints
- extension of the IP joints
- adduction of thumb/ finger
What are the investigations to be performed for hypocalcemia?
- Paired PTH/ Cal/ Po4/ Albumin
- 25 Vit D levels
- Creatinine – to assess renal function / CKD
- Magnesium – may lead to HypoCa
Patient has hypoCa. PTH is low, PO4 is high. Urine Ca:Cr = High. Differentials?
Activating mutation to the Ca Sensing Receptors in kidneys
Patient has hypoCa. PTH is low, PO4 is high. Urine Ca:Cr = low. Differentials?
Hypo PTH
- Di George
- surgical/ radiation
- infiltration
- autoimmune
HypoMg –> reduced parathyroid insufficeincy.
Patient has hypoCa. PTH is high, PO4 is low. Differentials?
Vitamin D Deficiency
Pancreatitis forming soaps = hypo Ca
Overhydration
Respiratory alkalosis
Drugs
- bisphosphonates
- phenytoin,
- calcium chelators
Patient has hypoCa. PTH is high, PO4 is high. Cr levels are high. Differentials?
Acute Renal Failure / AKI
Patient has hypoCa. PTH is high, PO4 is high. Cr levels are normal. Differentials?
Pseudo HypoPTH
- Albright hereditary osteodystrophy
- rhabdomyolysis
- massive tumour lysis syndrome
What is the management of mild hypoCa?
- Calcium 5mmol/6h PO
- Daily plasma Ca2+ levels
What is the management of severe hypoCa?
Correct Calcium
- Acutely, need 100-200mg elemental calcium in 10-20 min, i.e. give 10-20ml of IV Ca gluconate or IV 5ml Ca Chloride, over 2-5 mins
- Effects last for only 2-3 hours thereafter patient will become hypokalaemic again
Correct hypomagnesemia (causes PTH resistance + reduced secretion of PTH)
- Unlike HypoK where we need to correct Mg before K, there is no such need in the correction of HypoCa
- This is because Mg affects PTH and not Ca; whereas Mg affects K loss hence has to be corrected before providing K
Maintenance Calcium
- 0.5-1.5mg/kg elemental Calcium per hour
- Give 4 vials of Ca gluconate (360mg elemental Ca) or 2 vials of Ca chloride dilute in 500ml NS and run 6 hourly
- Check Ca 6 hourly
- Start Oral Ca and Rocaltrol (calcitriol / Vit D) concurrently
How do you manage hypoCa in a patient with elevated phosphate + hyperPTH 2’ to CKD/ ESRF and.
Control phosphate 1st
- Low Phosphate Diet
- Phosphate binder (Ca Based, Non-Ca based)
Medical Parathyroidectomy via Vit D (if 2’ HyperPTH), or Cinacalcet / Alphacalcidol (if 3’)
Calcium Supplementation
