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 direct access to the lungs. This is often necessary during surgeries or in emergencies when a patient needs assistance with breathing. The tube is connected to a ventilator, which helps deliver oxygen and remove carbon dioxide from the body. Proper placement of the endotracheal tube is crucial, as it ensures that air reaches the lungs effectively. Medical professionals, such as anesthesiologists and emergency room doctors, are trained to use this device safely.