What are the characteristics of tension pneumothorax?

Tension pneumothorax is characterized by the accumulation of air in the pleural space that results in increased pressure, leading to significant physiological changes. One of the hallmark features is the presence of decreased breath sounds on the affected side due to the lung being compressed by the trapped air. Additionally, hyperresonance is noted upon percussion of the chest in the area of the pneumothorax. This occurs because the presence of air in a confined space creates a sound that is more resonant than the normal lung or fluid-filled thoracic cavity.

Increased central venous pressure can also occur in tension pneumothorax due to the compression of blood vessels returning to the heart, but it is not one of the primary characteristics used to identify the condition at first presentation. Similarly, while bradycardia and hypotension may result from severe cardiorespiratory compromise in a tension pneumothorax, they are more secondary manifestations rather than defining characteristics. The primary assessment findings remain decreased breath sounds and hyperresonance on examination of the affected side.