Ministry of Health
Respiratory Distress Syndrome
Distress Syndrome (RDS) is a clinical diagnosis but one which is often
interchanged with the terms Hyaline Membrane Disease (a pathological
diagnosis) and Surfactant Deficiency (a term describing the typical
appearances on radiographs of infants with RDS).
The typical radiological
features of Surfactant Deficiency are:
- Small volume lungs
Homogenous "ground glass" opacity
These classical radiological
appearances have been altered by interventions such as CPAP (which tends
to result in lungs which are of normal size) and
administration (which is often given prior to the radiograph being
taken, and can result in less homogenous appearances).
The differential diagnosis
The middle image shows that the heart is
all but obscured by the diffuse, homogenous lung fields. The baby has
been intubated and there is are umbilical catheters in situ. This
radiograph was taken following
Transient Tachypnoea of the Newborn
Transient Tachypnoea of the Newborn (TTN, also called Retained Fetal Lung
Fluid or "Wet Lung") is a diagnosis of exclusion.
Typical radiologic features
are ill-defined but include:
- Increased central vascular
markings ("star-burst" appearance)
Evidence of interstitial and pleural fluid
Prominent interlobar fissures
Because the symptoms and
radiological features are non-specific, infection should be considered
in the differential diagnosis. Typically, respiratory symptoms
resolve within the first 24-hours of life, but occasionally can persist
chest radiograph appearances of pneumonia are not specific, and frank lobar
consolidation as seen in adults and older children is rare. More
commonly, there is coarse opacity of one or more regions of the lung
parenchyma. However, these appearances can also be seen with retained
fetal lung fluid, meconium aspiration, aspiration of gastric contents, and
pulmonary haemorrhage. Pleural effusions are not uncommon in
infection, but again may be seen with other conditions.
Group B Streptococcus can
have an appearance similar to
Respiratory Distress Syndrome
(Surfactant Deficiency), although the granulation is typically more
The top two images to the
left are of a baby with Listeria septicaemia and pneumonia. On the
top image, there is coarse opacity of both lungs but particularly of the
right side. There is a small pleural effusion on the right side,
seen as a thin line running parallel to the right costal margin.
The lower image taken the
following day demonstrates coarse bilateral opacity. No effusions
other images to the left are for a baby where the mother had
chorioamnionitis. She had been treated with antibiotics for a week,
but then developed fetal distress. The baby was born in poor
condition, and had a left-shifted full blood count, and was foul-smelling.
Cultures were negative in the infant despite the abnormal appearing chest
The AP film shows bilateral
patchy opacity, more marked on the right. No effusions are seen,
although these are relatively common with infection. The lateral
image shows patchy consolidation particularly in the lower lobes.
Meconium Aspiration Syndrome
Meconium stained amniotic fluid (MSAF) occurs in about 12% of deliveries.
Meconium aspiration is defined by meconium aspirated from below the vocal
cords. However, Meconium Aspiration Syndrome (MAS) defines a wide
array of respiratory symptoms associated with MSAF.
MAS usually presents as
respiratory distress and cyanosis. Pulmonary hypertension is
The radiograph usually shows
- Coarse infiltrates
Pleural effusions are not uncommon
Pneumothorax and pneumomediastinum may be present
Because the symptoms and
radiological features are non specific, infection should be included on
the differential diagnosis.
The images are from a term
infant born through thickly stained meconium liquor. The infant
had initial respiratory distress. She developed cyanosis and an
oxygen requirement. The initial two films show bilateral patch
opacity with hyperinflation (although not severe).
She deteriorated and was
ventilated. On the third image, she appears to have some air leak with a
prominent mediastinal lucency and some free air at the bases.
There is still patchy opacity of the lung fields.
She slowly improved after
about a week of intensive care including
inhaled nitric oxide,
before being extubated. The final film shows the post-extubation film with right
upper lobe collapse. She developed significant residual neonatal
chronic lung disease and was discharged on low-flow oxygen at the age of
Pulmonary haemorrhage is
relatively common in neonates. It can be dramatic in its onset, with a
catastrophic collapse, or it can be more subtle with blood-tinged
endotracheal secretions. In preterm infants, it is most commonly
associated with a patent ductus arteriosus causing haemorrhagic pulmonary
oedema. Other causes include surfactant administration (perhaps from a
rapid change in compliance resulting in an increase in the size of the
left-to-right shunt, and haemorrhagic oedema), airway haemangiomata (rare),
and any cause of pulmonary congestion (for example, severely reduced left
ventricular function in an asphyxiated or septic term infant).
Chest radiographs are
non-specific in appearance and commonly demonstrate patchy infiltrates,
although appearances can be normal.
Babies frequently require a
significant increase in their ventilatory support. The PEEP should
generally be increased in an attempt to maintain high mean airway
pressures so that oedema is forced back into the
pulmonary vascular bed.
Neonatal Chronic Lung Disease
|This is usually a sequel of significant lung
disease in the immediate newborn period. Classically, four stages were
described by Northway in 1967.
- Stage 1 was the homogenous
appearance of RDS
Stage 2 was a generalised opacity, frequently seen towards the end of
the first week of life
Stage 3 marked the onset of chronic changes, with a bubbly appearance
Stage 4 consisted of a inhomogenous appearance with hyperinflation, bleb
formation, irregular fibrous streaks, and cardiomegaly (from cor
Other scoring systems have
followed. These have largely been used in research rather than in
The first two radiographs
show appearances at 8 and 12 days in a baby born at 25 weeks. The
lung fields show a coarse bubbly appearance, initially more marked on
the right but then more widespread a few days later.
The radiograph at the bottom
shows advanced Stage 4 CLD. The infant is the same as in the
PDA image on the
"Cardiac Disease" radiology library. There is unevenness of the
ribs on the left side following a PDA ligation. The lung fields
are generally "bubbly" and "streaky" with localised areas of
hyperaeration in the right lower lobe and left lower lobe.
The strongest risk factor for
neonatal CLD is now gestation. Ventilation and oxygen may play a
role in the pathogenesis, as may infection with organisms such as
birth is an uncommon practice in our institution and in those maternity
hospitals who refer to our NICU. There is little evidence that water
immersion has benefits to the mother, and even less evidence suggesting
benefit to the infant. We have reported 4 cases of infants with
neonatal illness who were born through water (Nguyen S, Teele R, Kuschel C,
Spooner C. Waterbirth – a near drowning experience. Pediatrics
2002; 110 411-3).
Infants can be severely ill
initially and require ventilation, but frequently they improve with mild
respiratory support (oxygen and nasal CPAP). The chest radiographs are
not specific but frequently demonstrate pleural effusions and patchy
alveolar infiltrate. Infection must be considered in the
differential diagnosis, and antibiotics should be given at least until
cultures are proven negative. There are reports in the literature
of infants developing conjunctivitis with Pseudomonas and other
Hydrops describes a scenario of
fluid in at least two body cavities. The images to the left
demonstrate an infant with hydrops - in this case, bilateral pleural
effusions, ascites, and oedema.
The first image demonstrates
the appearance after birth. There is generalised oedema, bilateral
huge pleural effusions, and the right lung is seen as the (small) lucent
area slightly crossing the midline. Note the appearance of central
gas in the abdomen, suggesting the presence of ascites.
Following the insertion of
bilateral chest drains, there is residual fluid on the right side
particularly. The endotracheal tube is low.
The third image demonstrates
the appearance 3 days after birth. There has been a dramatic
reduction in the subcutaneous oedema. Bilateral pleural effusions
The cause of this baby's
hydrops was thought to be a congenital chylothorax. He was managed
with dietary manipulation using Monogen, without re-accumulation of his
pleural effusions. He was changed to breast feeding uneventfully
at three weeks of age.
The causes of hydrops are
extensive, and management in the delivery room is critical with many
babies requiring urgent insertion of chest drains, as well as abdominal
paracentesis, in order to achieve effective resuscitation. Senior
neonatal staff should be informed of the delivery and will usually
Refer to the
guideline for more information.
Tuesday, 29 November 2011