Transient Tachypnoea of the Neonate

Question 1

Outline the causes of respiratory distress in term infants

Answer 1

Question 2

Define

Answer 2

Parenchymal lung disorder characterised by pulmonary oedema resulting from delayed resorption and clearance of foetal alveolar fluid

Question 3

Aetiology

Answer 3

The MOST common cause of respiratory distress in TERM infants

Cause: DELAY in reabsorption of foetal alveolar lung liquid

More common in birth by Caesarean section (as chest is not squeezed to drain fluid + lack of hormonal stimuli (increase in adrenaline and glucocorticoids usually leads to reabsorption of water into foetal lung))

Question 4

Risk factors

Answer 4

• Delivery by caesarean section- usually ELCS > emergency
• Delivery < 39 weeks
• Precipitous delivery (really quick)
• Foetal distress
• Maternal sedation
• GDM

Question 5

Presentation

Answer 5

Tachypnoea (RR > 60 breaths per minute) at birth or within 2 hours after delivery

Cyanosis

Increased work of breathing- nasal flaring, mild intercostal and subcostal retractions, expiratory grunting

Anterior-posterior diameter of the chest may be increased

May be symptomatic for 12-24 hours

Symptoms and signs can be INTERMITTENT or OCCASIONAL

Signs can persist for as long as 72 hours in severe cases

Question 6

Investigations

Answer 6

CLINICAL diagnosis

Examination

Basic observations

Blood gas- mild-moderate hypoxaemia and mild hypercapnia (result in a respiratory acidosis)

CXR- may show fluid in the interlobar fissures and pleural effusions may be present, alveolar oedema (fluffy densities)- usually perihilar, flat diaphragm, hyperinflation

Lung USS

Question 7

Management

Answer 7

Supportive

Observe if just tachypnoea

Supplemental oxygen by hood or nasal cannulae (maintain O2 Sats > 92%)

• Nasal CPAP used if using > 40% oxygen or increased work of breathing + tachypnoea

Maintain neutral thermal environment and nutrition

• Provide nutrition- if RR > 60-80bpm, then use NG tube or TPN
• May give IV fluids- 10% dextrose, 60ml/kg/day- maintenance fluids

(Usually give IV fluids as NG tubes still require some work to be done to help get nutrition in)

If tachypnoea persists > 4-6 hours- begin antibiotics(ampicillin + gentamicin)

Fluid restriction may be needed in severe TTN

Consider an Echocardiogram if still not resolved by around day 4-5 (rule out cardiac cause)

Question 8

Complications

Answer 8

Complications

Respiratory distress

Prognosis

Usually settles within the first day of life (48-72 hours) but can take several days to resolve completely

Excellent prognosis when uncomplicated

Malignant TTN- develop PPHN due to possible elevation of pulmonary vascular resistance due to retained lung fluid (very RARE)

Some links with wheeze/ asthma later on in childhood