Wash your face, lips and nostrils with soap in the morning. During the operation, the operating area was disinfected with 1: 1000 benzalkonium bromide or 75% ethanol. Generally, blood transfusion is not needed during operation, but 5% glucose should be infused intravenously. Take the supine position during the operation, raise the shoulders to make the head lean back, which is not only convenient for the operation, but also allows the blood to accumulate in the nasopharyngeal cavity during the operation and not be inhaled into the lungs. However, any secretions and blood clots in the throat must be removed at any time during the operation. Maintaining respiratory tract from beginning to end during operation is the key to ensure the safety of operation.