Chest drain for ventilated pneumothorax — FFICM MCQ

Correct answer: B — Insert an intercostal chest drain using a safe image-guided approach

The correct answer is B, insert an intercostal chest drain using a safe image-guided approach. This patient is receiving positive pressure ventilation, which converts any pneumothorax into a high-risk lesion because each mandatory breath forces air into the pleural space through the visceral pleural defect with no route for egress, risking rapid progression to tension pneumothorax and cardiovascular collapse. Current UK pleural disease guidance holds that pneumothoraces in patients requiring positive pressure ventilation should be drained rather than observed, irrespective of size, because the usual conservative pathways for spontaneous pneumothorax do not apply once the chest is being ventilated mechanically. Ultrasound-confirmed absent lung sliding alongside radiographic confirmation gives the anatomical certainty needed to site the drain safely within the triangle of safety, and image guidance is recommended to reduce insertion complications. Definitive tube thoracostomy therefore takes precedence over observation, needle aspiration, ventilator manipulation, or extubation. Why the other options are wrong: D. Observe because he is currently stable: Current stability is deceptive because positive pressure ventilation continuously drives air into the pleural space, so the pneumothorax can convert to tension physiology within minutes without warning. C. Aspirate once and remove pleural access: Simple aspiration is a temporising measure for spontaneous pneumothorax in non-ventilated patients; it does not provide a route for continued air leak and will reaccumulate rapidly under positive pressure ventilation. E. Increase PEEP to re-expand the lung: Raising PEEP increases mean airway pressure and will worsen air leak into the pleural space, precipitating tension physiology rather than resolving it. A. Extubate immediately to avoid drainage: The patient requires ongoing ventilatory support for his underlying condition, and removing positive pressure does not treat the pneumothorax nor address the reason he is ventilated. Key point: Any pneumothorax in a patient requiring positive pressure ventilation mandates prompt intercostal chest drain insertion because of the imminent risk of tension physiology, regardless of current haemodynamic stability.

Reference: British Thoracic Society, Guideline for Pleural Disease 2023, Thorax; and BTS Clinical Statement on Pleural Procedures (safe insertion technique, triangle of safety, image guidance), https://www.brit-thoracic.org.uk