Pneumothorax

Commentary

Pneumothorax is an important complication in anaesthesia, trauma and medicine. This viva will concentrate both on the precise mechanisms by which pneumothoraces occur and on details of recognition and management. A pneumothorax can develop rapidly into a life-threatening emergency and so you must ensure that your management is competent.

The viva

You may be asked to list some of the common causes of pneumothorax, and explain how you would confirm the diagnosis.

Causes

• Traumatic: pneumothorax can follow penetrating injury, rib fracture or blast injury.

• Iatrogenic (surgical): it may occur during procedures such as nephrectomy, in spinal surgery, during tracheostomy (especially in children), laparoscopy, or as a consequence of oesophageal or mediastinal perforation.

• Iatrogenic (anaesthetic): pneumothorax may result from attempted central venous puncture and various nerve blocks, from barotrauma from mechanical ventilation at excessive pressures, and from high-pressure gas injector systems. Patients with emphysematous bullae are at risk.

• Miscellaneous: it may occur if the alveolar septa are weakened, as described above, and is associated with many pulmonary diseases, including asthma. There are some bizarre and unusual causes: recurring catamenial pneumothorax, for example, is a spontaneous pneumothorax, usually right-sided, which occurs in phase with the menstrual cycle. (By all means impress the examiners with this information, but do not cite it first.)

Diagnosis of pneumothorax in the awake patient

• Typical features (which are not invariable and which will depend on the size of the pneumothorax and whether or not it is expanding) include chest pain, referred shoulder tip pain, cough, dyspnoea, tachypnoea and tachycardia. There may be reduced movement of the affected hemithorax, hyperresonance on percussion, diminished breath sounds and decreased vocal fremitus.

• […]