Signs of Tension Pneumothorax
The signs of tension pneumothorax include absent breath sounds on the affected side, tachycardia, hypotension, and tachypnea, but NOT dullness to the chest on percussion or tracheal deviation towards the tension pneumothorax. 1, 2
Key Clinical Signs of Tension Pneumothorax
Absent breath sounds on the affected side - This is one of the most common clinical manifestations of tension pneumothorax, as air in the pleural space prevents normal sound transmission 1
Tachycardia - Increased heart rate is a compensatory mechanism that occurs due to decreased venous return and cardiovascular compromise in tension pneumothorax 2, 3
Hypotension - Low blood pressure results from increased intrathoracic pressure compressing the heart and great vessels, reducing cardiac output 1, 2
Tachypnea (rapid breathing) - Progressive difficulty breathing with fast, labored respiration is a hallmark sign of tension pneumothorax 1, 4
Additional Important Signs and Symptoms
Elevated chest wall on the affected side compared to the contralateral side 1
Subcutaneous emphysema and jugular vein distension due to increased pressure in the thoracic cavity 1
Progressive respiratory distress that rapidly worsens as air continues to accumulate 2, 3
Oxygen desaturation despite supplemental oxygen administration 4
Hyperresonance (not dullness) on percussion of the affected side due to increased air in the pleural space 4
Important Clinical Nuances
Tracheal deviation is typically AWAY from (not towards) the affected side - The Military Medical Research guidelines note that in a study of 111 cases of tension pneumothorax, no tracheal deviation was observed in any cases, making this an unreliable clinical sign despite being classically taught 1
Percussion reveals hyperresonance (not dullness) - Dullness to percussion would suggest fluid (as in hemothorax) rather than air in the pleural space 4
Altered mental status may occur in severe cases due to hypoxemia and decreased cerebral perfusion 4
Diagnostic Considerations
Tension pneumothorax is primarily a clinical diagnosis that should not be delayed for radiographic confirmation when suspicion is high 3
Point-of-care ultrasound can be helpful for diagnosis with reported sensitivity of 92.0% and specificity of 99.4% 1, 5
Ultrasound may reveal signs of tension physiology (mediastinal shift, dilated IVC) even before clinical decompensation occurs 5
Treatment Implications
Immediate needle decompression is required when tension pneumothorax is diagnosed, as it can cause death within minutes if not addressed promptly 2, 3
A No. 14 puncture needle (8.25 cm in length) is recommended for needle thoracentesis at the second intercostal space in the midclavicular line 1, 2
After initial decompression, tube thoracostomy should be performed for definitive management 1, 3