Endotracheal Tube - An Important Medical Device Used in Critical Care Endotracheal tubes, also known as ETTs, are flexible plastic tubes that are inserted through the mouth or nose and then threaded into the trachea (windpipe) to establish and maintain an airway during surgery or during a medical emergency. ETTs allow healthcare providers to control a patient's breathing by delivering oxygen or other gases directly into the lungs and removing carbon dioxide. They...