Neonatal respiratory distress Flashcards Preview

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Flashcards in Neonatal respiratory distress Deck (17)

Name 4 symptoms/signs of neonatal respiratory distress

Tachypnoea (> 60/min)
Increased WOB
Noisy breathing (stridor, wheeze, grunt)
Central cyanosis


Is a blue newborn always a pathological thing? Why/why not? If not, at what point should you start to worry?

No - babies are often blue when first born as foetus only has SaO2 around 60% in utero. Start to worry when SaO2 3 minutes after delivery


Name 2 transient causes of neonatal respiratory distress



Name 4 causes of neonatal respiratory distress in a term infant. Which is most common? Most dangerous?

Wet lung (Transient Tachypnoea of Newborn) - most common
Pneumonia - most dangerous
Meconium aspiration
Other (congenital heart defect, space occupying lesion)
HMD rare


Name 2 agents of neonatal pneumonia. What 2 antibiotics are usually used to treat?

Group B strep
Gram-negative bacilli

Use IV ben pen and gent


What causes transient tachypnoea of the newborn? What physiological factors affect this? What is its usual clinical course?

Imbalance in fluid production and removal of foetal lung liquid (continued production and delayed removal)

Adrenaline release on activity suppresses lung liquid production. Lymphatics and mechanical pressure of breathing remove fluid from lung.

Should improve over hours - days


Why might a newborn get meconium aspiration? Name 3 complications of meconium aspiration in a newborn. How do you manage it?

Can aspirate from gasping on initiation of breathing after delivery.

Block airways
Irritate lungs (pneumonitis)
Potentiate infection

Management - suction from level of trachea


What is the different outcomes of a complete vs incomplete airway blockage by meconium aspiration?

Complete = distal collapse
Incompete = air gets in (opens on inspiration) but not out = overinflation, pneumothorax


Go through the appearance on CXR of pneumonia, TTN and meconium aspiration of a newborn

Pneumonia - diffuse opacification
TTN - fluid in fissures
Meconium aspiration - overdistension (incomplete block), collapse (complete block), consolidation


Is meconium more likely to happen in an extreme preterm baby or a post-dates baby? Why?

Post-dates - the older the foetus, the more meconium it makes.


Name 3 diseases that can cause respiratory distress in a pre-term infant. Which is most common, and which is most dangerous?

HMD - most common
Pneumonia - most dangerous
Wet lung

Meconium aspiration unlikely


What role does surfactant have in lung function? When is it mostly released and what stimulates its release?

Reduces surface tension to stop alveoli from collapsing. Released mostly between 34-35 weeks after steroid release (but present from 22-24 weeks)


Name 3 pathophysiological processes that result from lack of surfactant release/HMD. Name 2 appearances of HMD on CXR

Increased surface tension = alveolar collapse = atelectasis
Can also result in leakage of proteins (= hyaline membrane in respiratory bronchioles) and fluid (= fluid on lung)

CXR - ground-glass appearance and/or collapsed lung


What is the positive feedback cycle that leads to severe HMD?

Surfactant deficiency = atelectasis = V/Q mismatching and shunting = pulmonary vasoconstriction = reduced alveolar type II cell metabolism = further surfactant deficiency


Name 5 risk factors for HMD

Maternal DM
Second twin


What are the two main principles of management of respiratory distress in a newborn?

Oxygenation and ventilation


Name the major SE of giving too much O2 to a newborn. What SaO2 should you aim for?

Retinopathy of prematurity. Aim between 90-95% (or thereabouts)