According to Baidu Health, some items of anesthesia evaluation need fasting, and some items don't.

1. Items requiring fasting: Both anesthetic drugs and anesthetic methods will affect the stability of patients' physical state. In order to reduce the risk of surgical anesthesia and improve the safety of surgical anesthesia, it is generally necessary to evaluate the general condition before surgical anesthesia. It usually includes routine laboratory examination and relevant auxiliary examination. For example, liver function, renal function, fasting blood glucose, biochemical tests, etc. Need to fast. If you have a history of diabetes, you need to check glycosylated hemoglobin, understand the blood sugar control in the past two or three months, and you need an empty stomach.

2. Items that do not require fasting: such as blood routine, urine routine, stool routine, chest X-ray, electrocardiogram and other items. If the patient has heart disease, you can also check the heart color ultrasound; If the patient has respiratory diseases, such as chronic bronchitis and emphysema, it is necessary to do lung function examination and blood gas analysis.

However, because most of the pre-anesthesia examination items are completed on the same day, it is generally recommended to have an empty stomach the day before.

Anesthesia evaluation: all anesthetics and anesthesia methods can affect the stability of patients' physiological state; Surgical trauma and bleeding can make the physiological function of patients in a state of stress; Surgical diseases and coexisting medical diseases have their own pathophysiological changes, which will cause a huge burden on the physiological potential of the body. In order to reduce this burden and improve the safety of surgical anesthesia, the general situation and physiological functions of important organs should be fully estimated before surgical anesthesia, and maintained and corrected as much as possible. This is an important link in surgical therapeutics and the main aspect of anesthesiologists' clinical work.