During surgery, after the anesthesia is administered, the patient lies flat on the surgical bed. The surgery takes a long time and the table can be a bit hard, which may cause pain in the patient’s back. Sometimes, the position needs to be changed during the surgery, such as laparoscopic surgery, which requires head high and right side high, or appendectomy, which requires head low and right side high. During the surgery, the patient may also have pain in the back, which can be relieved after rest. During laparoscopic surgery, carbon dioxide gas is filled inside the abdominal cavity. Carbon dioxide may affect the diaphragm and stimulate it, or carbon dioxide may be absorbed into the blood and form hypercapnia, which can also stimulate the diaphragm and cause pain at the back of the patient and pain in the shoulder. The duration of oxygen inhalation can be prolonged, and carbon dioxide gas can be expelled from the body as soon as possible through alveolar exchange.