Final answer:
The major complication of tension pneumothorax is obstructive shock due to increased intrathoracic pressure impairing venous return and cardiac output, leading to symptoms like breathlessness and potentially life-threatening consequences.
Step-by-step explanation:
When a patient has a tension pneumothorax, the major complication is obstructive shock. This occurs when air accumulates in the thoracic cavity and cannot escape, which increases intrathoracic pressure and subsequently impairs venous return to the heart, reducing cardiac output. The competing forces within the thorax are disrupted as the natural elasticity of the chest wall and the inward pull of the lungs, which are essential for the creation of negative intrapleural pressure and effective ventilation, are overshadowed by the accumulated air.
This excessive air within the thoracic cavity interferes with the oxygen delivery to tissues and can lead to serious health problems, including breathlessness, dizziness, headaches, and abdominal pain. In severe cases, it can be life-threatening, requiring emergency interventions such as needle decompression or chest tube insertion to release the trapped air and stabilize the patient.