This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'The best treatment of tension pneumothorax is - \nSelect and explain. \nA. Immediate letting out of air, B. Wait and watch, C. Rib resection, D. Underwater drainage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tension pneumothorax must be treated as a medical emergency. If the tension in the pleural space is not relieved, the patient is likely to die from the inadequate cardiac output or marked hypoxemia.\nA large-bore needle should be inserted into the pleural space through the second anterior intercostal space.\nIf large amounts of gas escape from the needle after insertion, the diagnosis is confirmed. The needle should be left in place until a thoracostomy tube can be inserted.', 'role': 'assistant'}]