A pneumothorax, or collapsed lung, occurs when the space between the parietal and visceral pleura of the lung fill with air, causing pressure on the lung that leads to its collapse. Most often, this occurs as the result of trauma, but it can also occur spontaneously, or as a complication after certain medical procedures. Diagnostic or treatment delays can lead to respiratory failure and death. A clinician in the Emergency Department would do well to maintain a high level of suspicion for this diagnosis in patients presenting with chest pain and shortness of breath.
What can complicate a clinician’s ability to make a swift diagnosis in the Emergency Department is that chest pain and dyspnea are commonly encountered symptoms. They can be attributed to several aetiologies, including acute coronary symptom, pulmonary embolism and thoracic aortic dissection (which I have discussed in a previous article). For a patient describing the sudden onset of these symptoms, without a history of recent trauma, a clinician should at least consider the diagnosis of spontaneous pneumothorax. A traumatic pneumothorax will exhibit very similar symptoms, however, the latter is more likely to occur shortly after a traumatic event or major medical intervention. (Sharma & Jindal, 2008)
Another important consideration is that pneumothoraces can be either simple or tension. While a diagnostic delay for either type can cause severe complications, a delay in diagnosing a tension pneumothorax is almost always deadly. Whereas a simple pneumothorax is non-expanding, a tension pneumothorax allows air to flow into the pleural space but not out of it. The pressure caused by the expansion can cause vascular collapse, eventually leading to cardiac arrest. If a tension pneumothorax is suspected and the patient is unstable, the attending clinician should proceed with decompression. Otherwise, obtaining a thorough medical history and imaging could help with an accurate diagnosis. (Leigh-Smith & Harris, 2005)
In otherwise healthy patients, a history of tobacco or cannabis use increases the risk for a pneumothorax. Underlying lung disease can also make a pneumothorax more likely to occur. Clinical signs of a pneumothorax include tachycardia (including sinus tachycardia), tachypnea, hypoxia and hypotension. Upon palpating the chest wall, the clinician should pay attention to crepitus, signs of trauma or respiratory distress.
Over the past decade there has been some debate revolving around the management of pneumothoraces using a traditional large-bore drain or a small-bore drain using the Seldinger technique. Although the latter has been thought to cause less discomfort for the patient due to reduced invasiveness, recent studies indicate that the lack of experience of the operator is a far greater indicator of patient discomfort and complications.
The bottom line is that when a patient presents to the ED with chief complaints of chest pain and shortness of breath, a clinician should at least consider a pneumothorax diagnosis. If a tension pneumothorax is suspected, decompression should be performed before proceeding with a detailed history and examination. Prompt diagnosis and appropriate treatment is necessary to prevent severe, long-term complications.