Traditionally, Fasting for more than 8 hours before operation is administered to reduce the risk of reverse flow and aspiration. ASA guidelines suggest a 2-hour fasting for clear fluid in healthy people before elective surgery. But in delivery women, the gastric emptying time is affected by the physiological change. This study is a prospective randomized controlled study to investigate the gastric emptying time of high energy digestible foods in delivery women, and the effect of high energy digestible food given before surgery on the comfort and metabolism of women undergoing Cesarean section. In the first step, 60 women in delivery room whose gastric volume less than 3.81 cm2 are randomly divided into three groups, 20 cases in each group. The experimental group (Group E1) is treated with high energy digestible food 300ml, Group G1 is given 5% glucose injection 300ml and Group N1 is given normal saline 300ml. The gastric volume was determined by ultrasonography once every hour until gastric volume less than 3.81cm2, and the time of gastric emptying was determined. The second step was to recruit 80 cases of full-term elective cesarean section. They were randomly divided into four groups, 20 cases in each group. The experimental group (Group E2) was given high energy digestible food 300ml before the time of gastric emptying found in the first step , Group G2 is given 5% glucose injection 300ml and Group N2 is given normal saline 300ml, while the control group (Group C2) was not given any diet. After admission to the operation room, the volume of the stomach was measured by ultrasound, and the differences of comfort, body temperature, shivering, blood glucose and postoperative anal exhaust time between the two groups were observed. This study is going to investigate the gastric emptying time of high energy digestible foods in delivery women, and the effect of high energy digestible food on the comfort, body temperature and blood glucose of women undergoing Cesarean section, so as to provide a good basis for reducing the surgery stress in women undergoing Cesarean section.

This study is a prospective randomized controlled study to investigate the gastric emptying time of high energy digestible foods in delivery women, and the effect of high energy digestible food given before surgery on the comfort and metabolism of women undergoing Cesarean section.

In the first step, 60 women in delivery room are enrolled, who are full term singleton pregnancy subjects ranging 18 to 50 years old and fasting for more than 8 hours. They are randomly divided into three groups, 20 cases in each group.

The experimental group (Group E1) is treated with high energy digestible food 300ml, Group G1 is given 5% glucose injection 300ml and Group N1 is given normal saline 300ml. The gastric volume was determined by gastric antrum cross-sectional area (CSA) measured with ultrasonography before drinking and once every hour after drinking. Once CSA is less than 3.81 cm2, the time is recorded as gastric emptying time of the woman. The overall gastric emptying time of high energy digestible food is determined with the 90 percentile gastric emptying time of women drinking high energy digestible food.

The second step was to recruit 80 cases of full-term elective cesarean section. They were randomly divided into four groups, 20 cases in each group. The experimental group (Group E2) was given high energy digestible food 300ml before the time of gastric emptying found in the first step, Group G2 is given 5% glucose injection 300ml and Group N2 is given normal saline 300ml, while the control group (Group C2) was not given any diet. After admission to the operation room, the volume of the stomach was measured by ultrasound, and the differences of comfort, body temperature, shivering, blood glucose and postoperative anal exhaust time between the two groups were observed.

This study is going to investigate the gastric emptying time of high energy digestible foods in delivery women, and the effect of high energy digestible food on the comfort, body temperature and blood glucose of women undergoing Cesarean section, so as to provide a good basis for reducing the surgery stress in women undergoing Cesarean section.

Inclusion Criteria:

• ASA (American Society of Anesthesiologist) grade II, full term singleton pregnancy subjects aged 18 to 50 years old;
• subjects undergoing elective cesarean section under combined spinal epidural anesthesia;
• volunteered to participate in the study and signed informed consent.

Exclusion Criteria:

• related drug allergies or taboo;
• Severe cardiopulmonary disorders (New York Heart Association Classification III-IV, or left ventricular ejection fraction < 30%) and liver and kidney dysfunction (alanine aminotransferase exceeding the upper limit of normal value twice, creatinine exceeding the upper limit of normal value 1.5 times), alcoholism history;
• there are metabolic diseases such as gestational diabetes mellitus, or using drugs that affect metabolism;
• the subjects were unable to cooperate or to communicate;
• the subjects suffered from psychosocial diseases;
• participated in other clinical trials within one month;
• there is drug abuse.