What are the symptoms and signs of tension pneumothorax?

Symptoms and Signs of Tension Pneumothorax

Tension pneumothorax is a clinical diagnosis characterized by progressive dyspnea and attenuated breath sounds on the affected side, requiring immediate needle decompression without waiting for radiographic confirmation. 1, 2

Cardinal Respiratory Symptoms

• Progressive dyspnea is the hallmark symptom, rapidly worsening over minutes and representing the most consistent finding 1, 2, 3
• Severe respiratory distress with rapid, labored breathing (tachypnea) develops as intrathoracic pressure increases 2, 4
• Difficulty breathing that does not improve with supplemental oxygen indicates severe compromise 4

Critical Physical Examination Findings

Pulmonary Signs

• Absent or markedly diminished breath sounds on the affected side is the most reliable auscultatory finding 2, 4, 5
• Hyperresonance to percussion on the affected side occurs due to trapped air 4
• Elevated chest wall on the affected side compared to the contralateral side 2

Cardiovascular Manifestations

• Hypotension results from decreased venous return as increased intrathoracic pressure compresses the heart and great vessels, reducing cardiac output 2, 3
• Tachycardia develops as a compensatory mechanism to maintain cardiac output 2, 4, 6
• Cardiovascular collapse can occur within minutes if untreated, progressing to shock with pallor and cold extremities 2, 3

Additional Clinical Signs

• Distended jugular veins occur due to increased pressure in the thoracic cavity, though this can be unreliable in supine patients 2, 5
• Subcutaneous emphysema may be palpable in some cases 2, 4
• Cyanosis appears in severe cases as oxygenation fails 4, 3

Late and Unreliable Signs

• Tracheal deviation away from the affected side is a classic but late sign, suggesting the tension pneumothorax has been developing for some time and should not be relied upon for diagnosis 2, 5
• The absence of tracheal deviation or distended neck veins does not exclude tension pneumothorax, as these findings are poorly sensitive 7

Special Clinical Contexts

Mechanically Ventilated Patients

• Sudden deterioration in intubated patients should raise immediate suspicion for tension pneumothorax 3, 8
• Increased airway pressures on the ventilator and difficulty bagging the patient are key indicators 8, 5
• Positive pressure ventilation can rapidly convert a small, asymptomatic pneumothorax into a life-threatening tension pneumothorax 3, 8

Battlefield/Trauma Settings

• History of thoracic injury combined with progressive dyspnea and attenuated breath sounds establishes the diagnosis 1
• Environmental noise may prevent effective physical examination, making portable ultrasound valuable 1

Diagnostic Adjuncts

• Point-of-care ultrasound can identify tension physiology (mediastinal shift, dilated IVC) with 92% sensitivity and 99.4% specificity, even before clinical decompensation 2, 7
• Chest radiography should never delay treatment when clinical suspicion is high, as tension pneumothorax is fundamentally a clinical diagnosis 3

Critical Pitfall to Avoid

Do not wait for radiographic confirmation or the appearance of late signs like tracheal deviation before initiating needle decompression. The condition can cause death within minutes, and immediate decompression based on clinical presentation (progressive dyspnea, absent breath sounds, hypotension, respiratory distress) is lifesaving. 2, 3, 5