Hypocalcaemia

Question 1

Causes:

What endocrine disorder can cause this?

Low Vit D is the MAIN cause. What are some causes of this?

Answer 1

Hypoparathyroidism

Low sun exposure
Low dietary intake
Coeliac disease
Liver or kidney failure

Question 2

Causes:

What other electrolyte if low would inhibit the release and effects of PTH?

CKD - Phosphate is controlled by the kidneys. Would phosphate be increase or decreased in this case?

What other acute pathology could cause this?

What drugs could cause hypocalcaemia?

Answer 2

Magnesium - hypomagnesaemia - needed for PTH secretion

Increased phosphate and therefore failed vit d hydroxylation

Acute pancreatitis
Acute rhabdomyolysis

Biphosphonates
Phosphates

Question 3

Why does hypocalcaemia cause neuromuscular excitability?

Answer 3

Low ionized calcium levels in the extracellular fluid increase the permeability of neuronal membranes to sodium ion, causing a progressive depolarization, which increases the possibility of action potentials.

Question 4

Presentation - neuromuscular excitability:

• What is a carpopedal spasm?
• What is chvostek’s sign?
• What is trousseau’s sign?
• What 2 things could happen to the airway?
• Where do they get paraesthesia (numbness)?

Answer 4

Tetany (involuntary contraction) of feet or hands

Facial twitch on parotid tap

Carpal tetany in response to tightened BP cuff

Laryngospasm
Bronchospasm

Peripheries (hands and legs)
Tongue
Mouth

Question 5

Presentation (chronic disease):

• What happens to the lens of the eye in chronic disease?
• What happens to their skin?
• What may happen to their teeth if the patient is young?
• What CNS symptoms do they get?

Answer 5

Cataracts

Dry
Coarse
Puffy skin

Reduced tooth growth 
---- 
Seizures 
Papilloedema 
Dementia 
Parkinsonism 
Anxiety 
Depression 
Fatigue

Question 6

Signs:

Facial twitch on parotid tap - what is this called?

Carpal tetany in response to tightened BP cuff - what is this called?

Tetany (involuntary contraction) of feet or hands - what is the name of the spasm?

Answer 6

Chvostek sign

Trousseau’s sign

Carpopedal spasm (carpo = hand, pedal = feet)

Question 7

SPASMODIC IS USED AS A MNEUMONIC - WHAT DOES IT STAND FOR?

Answer 7

Spasms (e.g. Trousseau’s sign)

Paraesthesiae (perioral, hands and feet) / Prolonged QTc interval

Anxious, irritable, irrational

Seizures

Muscle tone increase in smooth muscle – colic, wheeze dysphagia

Orientation impaired and confusion

Dermatitis

Impetigo herpetiformis

Chvostek’s sign, Choreoathetosis, Cataract,

Cardiomyopathy

Question 8

Investigations:

What levels do you expect the phosphate to be?

Do rest of investigations to look for cause!!!!

Answer 8

High levels of phosphate - remember always the opposite

Question 9

Management:

What can be done to treat this? - 2

What can be given IV if it is very severe (e.g. tetany, paraesthesia)?

Answer 9

Calcium supplements + Calcitriol (Vit D)

Calcium glutinate

Question 10

LOOK AT ORTHOPAEDICS FOR OSTEOMALACIA AND RICKETS

Answer 10

LOOK AT ORTHOPAEDICS FOR OSTEOMALACIA AND RICKETS