5. Paediatrics (Chest) Flashcards
Croup (4)
Commonest cause of acute upper airway obstruction in young children, typically aged 6 months to 3 years.
Barky “Croopy” cough.
Viral. Usually parainfluenza virus.
AP and lateral neck X ray is to rule out other pathology, but “steeple sign” (loss of normal lateral convexities of the subglottic trachea) is buzzword.
Epiglottitis (5)
Can kill. Due to H.Influenza, classically 3.5 years old.
Lateral X ray shows marked swelling of epiglottis (thumb sign).
“Omega Epiglottitis” - caused by oblique images, is a mimic. Thickening of the aryepiglotic folds to distinguish.
Kills by asphyxiation, from aryepiglotic folds..
Exudative tracheitiis (3)
Rare but serious infection in ages 6-10.
Caused by exudative infection of trachea, from Staph A usually.
“Linear soft tissue filling defect within the airway”
Retropharyngeal cellulitis and abscess (4)
Usually 6-12 months old.
Lateral X ray shows massive retropharyngeal soft tissue thickening. Can get pseudothickening when neck isn’t truly lateral. Repeat with neck in extension may be needed to distinguish.
CT will be more obvious, mimic will be a lateral low density node.
Subglottic haemangioma (5)
Most common soft tissue tracheal mass, most commonly in subglottic region.
Croup has symmetric narrowing with loss of shoulders on both sides “steeple sign”. Subglottic haemangiomas have loss of just one side.
Tends to favor left side.
50% associated with cutaneous haemangiomas.
7% have PHACES syndrome
PHACES syndrome (6)
Posterior fossa (Dandy walker)
Haemangiomas
Arterial anomalies
Coarctation of aorta, cardiac defects
Eye abnormalities
Subglottic haemangiomas
Frontal neck X-ray DDx (3)
Frontal: consider croup and subglottic haemangioma
- Can tell them apart by shouldering.
- If can’t, history will distinguish (fever/cough = croup)
Lateral neck X-ray DDx (8)
Epiglottitis
- Looks like thumb. Pt should ideally get portable film.
Retropharyngeal abscess
- Too wide (>6mm at C2, >22mm at C6)
- Needs CT (look in the mediastinum for “danger zone” expansion)
Tonsils (adenoids)
- Not seen until 3-6 months, not big until 1-2 years.
- Too big if they encroach the airway
Exudative tracheitis
- Linear filling defect. Usually staph.
Meconium aspiration (5)
Typically occurs due to stress (hypoxia), more common in term or post-mature babies.
Pathophysiology is due to chemical aspiration
“Ropy appearance” of asymmetric lungs
Hyperinflation with alternative areas of atelectasis
Pneumothorax in 20-40%
Hyperinflation is due to air trapping from ball-valves created by inhaled meconium.
Transient tachypnoea of Newborn (4)
Associated with C-section, maternal diabetes or maternal sedation.
Findings start at 6hrs, peak at 24hrs and resolve by 3 days.
Coarse interstitial markings and fluid in the fissures.
Lung volumes are normal to increased.
Surfactant-deficient disease (5)
aka hyaline membrane disease or RDS.
Disease of premature lungs, born with too little surfactant.
Most common cause of death in premature newborns.
Reduced lung volumes and bilateral granular opacities (like B-haemolytic pneumonia, but without pleural effusions).
Normal CXR at 6 months excludes SDD.
Surfactant replacement therapy (4)
Sprayed into lungs, decreases death rate, lung volumes increase and granular opacities clear after treatment.
Post treatment: bleb-like lucencies, can mimic PIE.
Increased risk of pulmonary haemorrhage.
Increased risk of PDA.
Neonatal pneumonia (7)
Non-Beta haemolytic strep
- Lots of causes.
- Usually patchy, asymmetrical hilar densities and hyperinflation.
- Looks similar to surfactant deficient disease but full term baby.
Beta-haemolytic strep
- Most common pneumonia in newborns. Acquired during exit of birth canal.
- Affects premature infants more.
- Often decreased lung volumes (unlike other pneumonias)
- Granular opacities and often has pleural effusion.
Persistent pulmonary hypertension (4)
Also called persistent foetal circulation.
High pulmonary pressures in utero normally decrease after first breath.
Persistent high pressures can be primary or secondary, due to hypoxia (meconium aspiration, pneumonia).
CXR shows cause of pulmonary HTN (e.g. pneumonia) rather than HTN itself.
Important newborn chest buzzwords (4)
“post term baby” = Meconium aspiration
“C-section” = Transient Tachypnoea of Newborn
“Maternal sedation” = Transient Tachypnoea of Newborn
“Premature” = RDS
High vs Low lung volume DDx (5)
High
- Meconium aspiration
- Transient tachypnoea
- Neonatal pneumonia
Low
- Surfactant deficiency (no pleural effusion)
- Beta hamolytic pneumonia (pleural effusion)
Pulmonary Interstitial Emphysema (6)
Surfactant deficiency + ventilator, can end up with air escaping the alveoli and ending up in interstitium and lymphatics.
CXR: Linear lucencies (buzzword). Warning sign for impending pneumothorax.
Most occur in first week of life (bronchopulmonary dysplasia, looks similar, occurs after 2 weeks).
Surfactant therapy can also mimic PIE.
Rx: Switch ventilation methods and/or place patient on affected side down.
Can progress to large cystic mass, can even cause mediastinal mass effect
Chronic lung disease (Bronchopulmonary Dysplasia) (3)
Classically premature child with resulting surfactant deficiency on prolonged ventilation.
After week 2, hazy lungs which coarsen over next few months to give bubble like lucencies.
Band like opacities is a buzzword.
Pulmonary hypoplasia (5)
Can be primary or secondary, due to:
- Decreased hemi-thoracic volume
- Decreased vascular supply
- Decreased fluid.
Most common is decreased thoracic volume, usually due to space occupying mass such as congenital diaphragmatic hernia (bowel in chest), neuroblastoma or sequestration.
Decreased fluid refers to Potter sequence (no kidneys –> no pee –> no fluid –> hypoplastic lungs)
Bronchopulmonary sequestration (5)
Interlobar and extralobar, depending on whether there is a pleural covering.
Venous drainage is different (intra into pulmonary veins, extra into systemic veins).
Cannot distinguish radiologically.
Intralobar presents in adolescence or adulthood with recurrent pneumonias.
Extralobar presents in infancy with respiratory compromise.
Intralobar sequestration (2)
More common (75%). Most commonly left lower lobe, posterior segment (2/3).
Rarely associated with other developmental abnormalities.
Extralobar sequestration (8)
Less common (25%).
Presents in infancy with respiratory compromise - mainly due to associated anomalies:
- congenital cystic adenomatoid malformation (CCAM),
- congenital diaphragmatic hernia
- Vertebral anomalies
- congenital heart disease
- Pulmonary hyperplasia
Rarely infected as it has pleural cover.
Sometimes described as part of bronchopulmonary foregut malformation, can rarely have patent channel to stomach or distal oesophagus.
Bronchogenic cysts (2)
Usually incidental, usually solitary and unilocular.
Don’t usually communicate with the airway. If they contain gas, sign of infection.
