Anatomy Thorax Abdomen · Year 1 · from Anatomy Thorax Abdomen
Case 3: Tension Pneumothorax
Clinical Presentation
A 35-year-old male is brought to the trauma bay after a high-speed motor vehicle collision. He was an unrestrained driver who struck the steering wheel. Upon arrival, he is in severe respiratory distress with a respiratory rate of 32 breaths per minute, oxygen saturation of 82% on high-flow oxygen, heart rate of 130 beats per minute, and blood pressure of 80/50 mmHg. Examination reveals distended neck veins, tracheal deviation to the left, absent breath sounds on the right, and hyperresonance to percussion on the right.
The clinical diagnosis of tension pneumothorax is made and immediate needle decompression is performed at the right second intercostal space at the midclavicular line. A rush of air is heard, and the patient's vital signs improve within seconds. Blood pressure rises to 110/70 mmHg and oxygen saturation improves to 96%. A chest tube is subsequently placed, and post-procedure chest radiograph confirms lung re-expansion.
Key Anatomical Points
- Tension pneumothorax occurs when a one-way valve mechanism allows air to enter the pleural space during inspiration but prevents its escape during expiration
- Progressive air accumulation increases intrapleural pressure, causing mediastinal shift toward the contralateral side
- Mediastinal shift compresses the contralateral lung and kinks the great veins (superior and inferior vena cava), reducing venous return and causing cardiovascular collapse
- The trachea deviates away from the side of the tension pneumothorax
Key Learning Points
- Tension pneumothorax is a clinical diagnosis - treatment should never be delayed for radiographic confirmation
- Needle decompression is performed at the second intercostal space at the midclavicular line or the fifth intercostal space at the anterior axillary line
- The needle must pass immediately above the rib to avoid the intercostal vessels and nerve
- Understanding the pleural space anatomy is essential for recognizing and treating this life-threatening condition