Neonatal Respiratory Distress

Question 1

Describe the signs of respiratory distress in a neonate?

Answer 1

RR >60
Recession (sternal, intercostal, subcostal)
Tracheal tug
Cyanosis

• Expiratory grunting (breathing out against a closed epiglottis in order to maintain positive pressure in the airways.)
• Wheeze
• Stridor

Question 2

What are the different causes of respiratory distress in neonates?

Answer 2

• Transient tachypnoea
• Respiratory distress syndrome
• Congenital pneumonia
• Meconium aspiration
• Congenital anomalies (heart/diaphragmatic hernia)
• Any septicaemia (Group B strep is most common)

Question 3

What is transient tachypnoea, how will it appear on X-ray and what is the treatment?

Answer 3

Transient tachypnoea of the newborn is the most common cause for neonatal respiratory distress.

It is caused by delayed reabsorption of lung fluid and is more common after c-sections.

On an X-ray may be able to see a horizontal fissure.

It is a self limiting condition and usually resolves after the 1st day of life. The diagnosis should only be given after excluding more serious causes. Oxygen may be required.

Question 4

What is respiratory distress syndrome?

Answer 4

Respiratory distress syndrome is caused by a deficiency in surfactant and an immature respiratory centre in the brain.

Surfactant is produced by type 2 alveolar cells and lowers the surface tension of the alveolar air sacs.

It is much more common in premature babies due to the lungs not having sufficient time to mature.

It is also more common in babies with diabetic mothers and in those with meconium aspiration.

Question 5

How does respiratory distress syndrome present?

Answer 5

Presents within 4 hrs post partum as is characterised by grunting. (breathing against the epiglottis to try and maintain a positive pressure in the lungs)

Question 6

How should respiratory distress syndrome be treated?

Answer 6

Antenatal:

If a mother is giving birth less than 34 weeks 2 doses of corticosteroids are given within 48hrs of delivery (betamethasone/dexamethasone)

Postpartum:

If the baby is suffering from respiratory distress syndrome it can be given artificial surfactant. This has greatly reduced neonatal deaths due to prematurity.

Question 7

What increases the risk factors of developing congenital pneumonia?

Answer 7

Prolonged rupture of the membranes,
Chorioamnionitis (infection of the amnion and chorion)
Low birth weight

Question 8

How does congenital pneumonia present and managed?

Answer 8

Neonate in respiratory distress
Floppy
Mottled (generally unwell)
Not feeding

Any suspected infection treated with IV broad spectrum antibiotics (low threshold)

Septic screen

Question 9

What is meconium aspirate?

Answer 9

It is when the meconium is aspirated by the neonate before delivery.

Meconium is passed before birth by 8-20% of babies and occurs more commonly in this with greater gestational age (rare in premature).

If this happens the meconium may be aspirated by the fetus.

Meconium is a lung irritant and result in both mechanical obstruction and chemical pneumonitis (destroys surfactant), as well as causing a aspiration pneumonia.

Question 10

How does meconium aspirate appear on x-ray and what is the treatment?

Answer 10

The lungs become over inflated, accompanied by patches of collapse and consolidation.

There is a high incidence of air leak leading to pneumothorax.

Treatment is often with ventilation, artificial surfactant and prophylactic antibiotics (abx is currently being debated argument that it should only be used in suspected cases)

Question 11

Which congenital heart abnormalities are more likely to cause respiratory distress in a neonate?

Answer 11

Cyanotic abnormalities:

• Transposition of the great aa
• Hypoplastic left heart syndrome
• Severe coarctation
• Tricuspid atresia
• Potentially ToF may not cause respiratory distress until later