Pneumothorax and air-leak syndromes — viva

Opening (must-hit)

"With any air leak my first question is whether it is under tension, because that changes the next sixty seconds. A shocked child with unilateral absent breath sounds, distended neck veins and a shifted trachea has a tension pneumothorax, which I decompress on clinical grounds before any imaging. Once stable, I ask why the lung leaked — primary spontaneous on a normal lung, secondary on abnormal lung, traumatic, or neonatal — then I size the leak and escalate from oxygen and observation through aspiration and drainage to surgery, while treating the underlying cause." [1] [2] [5]

Branch A — Tension recognition

Examiner: How do you recognise a tension pneumothorax, and what do you do? Candidate: Tension is a clinical diagnosis: severe distress and hypoxia with hypotension, tachycardia, distended neck veins, tracheal deviation away from the side, and unilateral absent breath sounds. In a ventilated child the first sign is often a sudden rise in oxygen requirement and a fall in blood pressure. I give oxygen and decompress immediately with a needle or finger thoracostomy, then place a chest drain — I never wait for a chest X-ray. [2] [7]

Branch B — Primary versus secondary

Examiner: Why does it matter whether a spontaneous pneumothorax is primary or secondary? Candidate: A primary spontaneous pneumothorax occurs on a structurally normal lung, classically a ruptured apical bleb in a tall thin adolescent with reasonable reserve, so conservative observation is often appropriate. A secondary pneumothorax occurs on abnormal lung — cystic fibrosis, asthma, connective-tissue disease — where reserve is low, symptoms are worse, and the leak is more likely to persist and recur, so I have a lower threshold to drain, admit and involve surgery. [5] [8]

Branch C — Conservative management evidence

Examiner: A stable 15-year-old has a moderate primary spontaneous pneumothorax and few symptoms. Must you drain it? Candidate: Not necessarily. The trial of conservative versus interventional treatment showed watchful waiting was non-inferior for re-expansion with fewer adverse events in selected stable patients, and paediatric practice is moving the same way. I would give oxygen to speed resorption, observe with repeat imaging, and reserve aspiration or a small-bore drain for larger, symptomatic or progressing leaks, using ambulatory devices where appropriate. [1] [2]

Branch D — The Macklin route

Examiner: How can one alveolar rupture cause pneumothorax, pneumomediastinum and surgical emphysema together? Candidate: Through the Macklin effect. An overdistended alveolus ruptures at its base and air dissects along the perivascular sheaths to the hilum and mediastinum, giving pneumomediastinum, from where it can decompress into the neck as surgical emphysema or rupture into the pleura as a pneumothorax. Air trapped in the interstitial planes forms pulmonary interstitial emphysema. They share one origin, which is why they coexist. [12] [7]

Branch E — The collapsing neonate

Examiner: A ventilated preterm infant suddenly desaturates and drops their blood pressure. Your approach? Candidate: I treat this as a tension air leak until proven otherwise. I run the DOPES check — displaced or obstructed tube, pneumothorax, equipment failure, stacked breaths — give oxygen, and if tension pneumothorax is likely I confirm rapidly with transillumination and decompress with needle aspiration then an intercostal drain, matching needle length to the thin chest wall. I then reduce ventilator pressures to limit further barotrauma. [7] [12]

Branch F — Cystic fibrosis

Examiner: What does a pneumothorax mean in a teenager with cystic fibrosis? Candidate: It marks advanced lung disease and a worse prognosis. I would place an intercostal drain rather than simply observe, involve the CF team and thoracic surgery early, maintain airway clearance, and weigh definitive pleurodesis carefully against future transplant candidacy, since extensive pleurodesis can complicate transplantation. [8] [2]

Branch G — Recurrence and prevention

Examiner: How do you reduce the chance of another pneumothorax? Candidate: I counsel every adolescent to stop smoking and vaping, to avoid diving and unpressurised flight until reviewed, and to return promptly with recurrent symptoms. Recurrence is common on the same side, so after a recurrent primary or a first secondary event I discuss video-assisted thoracoscopic bleb resection with pleurodesis, which markedly lowers recurrence. [5] [1]