Hypocalcaemia And Hypomagnesaemia

Question 1

What is regarded as hypocalcaemia?

Answer 1

Serum calcium concentrations below 2.0 mmol/l

Question 2

What is regarded as hypomagnesaemia?

Answer 2

Serum concentrations below 0.7 mmol/l

Question 3

What are the clinical signs of hypocalcaemia and hypomg?

Answer 3

Infants may be entirely asymptomatic. Common signs: increased irritability, twitching, vomiting and occasionaly convulsions. Tetany is not seen in the newborn

Question 4

What are common causes of hypoca and hypomg?

Answer 4

• preterm infants esp if there is severe illness
• underweight for gestational age
• infants of diabetic mothers
• infants who suffered perinatal hypoxia
• during exchange transfusion

Question 5

What are rare causes of hypoca and hypomg?

Answer 5

• renal failure
• hypoparathyroidism
• infant fed undiluted cows milk

Question 6

How is hypoca treated?

Answer 6

Calcium may be given orally or as part of IV fluids. Give 10 ml 10% calcium gluconate in an infusion over 24 hours

Question 7

Why is rapid correction of hypoca dangerous?

Answer 7

May cause cardiac arrest

Question 8

How is hypomg treated?

Answer 8

Magnesium is administered as magnesium sulphate (0.2ml/kg of 50% solution) by IM route

Question 9

Why do serum calcium and magnesium concentrations normally fall after birth?

Answer 9

Decreased parathyroid function and/ or renal insensitivity for the first 48 hours.