Pediatric Pulmonology
This domain tests asthma control and exacerbation management, the recognition of bronchiolitis and croup, and the diagnosis of cystic fibrosis.
Asthma
- Diagnosis rests on recurrent reversible airflow obstruction; in children the FEV1/FVC ratio is normally above 0.90.
- Inhaled corticosteroids are the controller of choice; short-acting beta-agonists are relievers only.
- Acute exacerbation: oxygen to keep saturation above 92-94%, repeated salbutamol, add ipratropium in severe attacks, give systemic corticosteroids (prednisolone 1-2 mg/kg), and consider intravenous magnesium sulfate for severe or life-threatening disease.
Bronchiolitis
- Under 2 years, usually respiratory syncytial virus, with coryza followed by wheeze, crackles and tachypnea.
- Management is supportive: oxygen if saturation falls below 90-92%, hydration and suctioning. Bronchodilators, corticosteroids and antibiotics are not indicated.
Croup and epiglottitis
- Croup: barking cough, hoarse voice, inspiratory stridor; treat with a single dose of dexamethasone, and nebulised epinephrine for moderate to severe disease.
- Epiglottitis: drooling, tripod positioning, high fever, no cough; never inspect the throat outside the operating theatre.
Cystic fibrosis
- Meconium ileus, growth faltering, steatorrhoea, salty sweat and recurrent pulmonary infection.
- Diagnosis: sweat chloride of 60 mmol/L or more on two samples; 30-59 is intermediate and warrants CFTR genotyping. Newborn screening uses immunoreactive trypsinogen.
- Management: pancreatic enzyme replacement, fat-soluble vitamins, airway clearance, hypertonic saline, and CFTR modulators.
Worked example
A 10-month-old has its first wheezing illness with coryza, mild retractions and SpO2 94%. Reasoning: this is bronchiolitis, not asthma. Give supportive care, suction the nose and maintain hydration; a beta-agonist trial is not routine.
Traps
Diagnosing asthma after a single wheeze; prescribing corticosteroids for bronchiolitis; and inspecting the throat in suspected epiglottitis.