An endotracheal tube is a medical device used to maintain an open airway in patients who are unable to breathe on their own. It is a flexible tube that is inserted through the mouth or nose and into the trachea, allowing for ventilation and the delivery of oxygen. This procedure is often performed during surgeries or in emergency situations. The tube is connected to a ventilator, which helps to deliver air and oxygen to the lungs. Proper placement of the endotracheal tube is crucial, as it ensures that the airway remains clear and prevents aspiration of fluids. Medical professionals, such as anesthesiologists and emergency medical technicians, are trained to perform this procedure safely.