From the Guidelines
Tension pneumothorax is differentiated from non-tension pneumothorax by its clinical presentation, characterized by severe respiratory distress, hypotension, tachycardia, and hemodynamic compromise, whereas non-tension pneumothorax presents with less severe symptoms and no significant hemodynamic compromise. The key features of tension pneumothorax include rapid deterioration in cardiopulmonary status, impaired venous return, reduced cardiac output, and hypoxaemia, as noted in the BTS guidelines for the management of spontaneous pneumothorax 1. In contrast, non-tension pneumothorax may present with dyspnea, pleuritic chest pain, and decreased breath sounds on the affected side, but without significant hemodynamic compromise.
Clinical Presentation
The clinical presentation of tension pneumothorax is striking, with patients rapidly becoming distressed, exhibiting rapid laboured respiration, cyanosis, sweating, and tachycardia, as described in the guidelines for radiologically guided lung biopsy 1. The development of tension in a pneumothorax is not dependent on the size of the pneumothorax, and the clinical scenario may correlate poorly with chest radiographic findings.
Diagnostic Features
The diagnostic features of tension pneumothorax include:
- Severe respiratory distress
- Hypotension
- Tachycardia
- Distended neck veins
- Tracheal deviation away from the affected side
- Absent breath sounds on the affected side
- Hypoxemia
- Mediastinal shift away from the affected side on chest X-ray
- Depression of the ipsilateral diaphragm on chest X-ray
Management
The critical distinction in management is that tension pneumothorax requires immediate needle decompression with a large-bore needle in the second intercostal space, mid-clavicular line, followed by chest tube placement, as recommended in the BTS guidelines for the management of spontaneous pneumothorax 1. In contrast, non-tension pneumothorax can be managed less urgently with observation (for small pneumothoraces) or standard chest tube placement depending on size and symptoms. The use of high-flow oxygen therapy can increase the rate of pneumothorax reabsorption, as noted in the BTS guidelines for the management of spontaneous pneumothorax 1.
From the Research
Differentiating Tension from Non-Tension Pneumothorax
To differentiate between tension and non-tension pneumothorax, several factors and diagnostic tools can be considered:
- Clinical presentation: The clinical presentation of tension pneumothorax can vary depending on the patient's ventilatory status 2. Patients who are breathing unassisted may present with hypoxia, while those receiving assisted ventilation are more likely to experience hypotension and cardiac arrest.
- Diagnostic imaging: Lung ultrasound (US) has been shown to be a useful tool in detecting pneumothorax, particularly in the trauma bay 3. Computed tomography (CT) remains the gold standard for confirming the presence and measuring the size of a pneumothorax.
- Physical signs: The physical signs of tension pneumothorax, such as hypoxia and pulmonary dysfunction, can progress rapidly in patients receiving assisted ventilation 2.
- Patient symptoms: Patients with tension pneumothorax may present with severe respiratory distress, chest pain, and decreased breath sounds on the affected side.
Diagnostic Approaches
The following diagnostic approaches can be used to differentiate between tension and non-tension pneumothorax:
- Chest x-ray (CXR): While CXR is traditionally used to diagnose pneumothorax, lung US has been shown to be more sensitive and specific in detecting traumatic pneumothorax 3.
- Lung ultrasound: Lung US can be used to quickly and accurately diagnose pneumothorax in the trauma bay 3.
- Clinical evaluation: A thorough clinical evaluation, including assessment of the patient's ventilatory status, can help differentiate between tension and non-tension pneumothorax 2.