Preoperative diet guide: 2468 Are you ready to "fasting"?

This is the 4981st article of Da Yi Xiao Hu

Dietary preparation before surgery is a crucial step. Reasonable dietary preparation is an important guarantee for successful surgery and rapid recovery after surgery.

Preoperative diet guide for patients undergoing elective surgery

Suitable food before surgery

High-protein foods

Such as lean meat, fish, poultry, beans and bean products. Protein is the basic substance for the body to repair tissues. Sufficient protein intake helps to enhance immunity and promote postoperative wound healing.

Vitamin-rich foods

Fresh fruits and vegetables are rich in vitamins, especially vitamin C and vitamin A. These vitamins have antioxidant effects, can help the body recover and promote wound healing.

Fiber-Rich Foods

Whole grains, vegetables, fruits, etc. are rich in fiber, which can help maintain intestinal health and prevent constipation. This is especially important after surgery because many postoperative patients are prone to constipation due to reduced activity and the effects of medication.

Unsuitable food before surgery

High-fat foods

Such as fried foods, fast food, fatty meat, etc. High-fat foods are not only difficult to digest, but may also increase the risk of surgical complications because they may cause gastrointestinal reactions and affect the metabolism of anesthetic drugs.

Stimulant food and drink

Including spicy food, alcohol, coffee, strong tea, etc. These foods and drinks may irritate the gastrointestinal tract, cause discomfort during or after surgery, and even affect wound healing.

Why do you not eat or drink before anesthesia?

In order to prevent patients from experiencing nausea and vomiting during surgical anesthesia induction, they must not eat or drink before anesthesia, because patients will lose consciousness after taking anesthetics. If there is food in the stomach, the food may reflux into the esophagus and be accidentally inhaled into the respiratory tract or even into the lungs through the oropharynx, leading to aspiration pneumonia. In severe cases, respiratory failure may occur and endanger the patient's life.

Guidelines for fasting and drinking before anesthesia

Preoperative dietary management was summarized based on the preoperative fasting practice guidelines issued by the American Society of Anesthesiologists (ASA) in 2023.

Principle 2468: The main components of daily diet are carbohydrates, fats and proteins. Due to their different chemical structures, the time they are emptied from the stomach and the parts where they are digested and absorbed are also different. Therefore, different fasting and drinking times are set according to the different types of intake.

“2” Clear fluids can be taken 2 hours before anesthesia, which can effectively reduce the patient’s thirst and hunger, and will not increase the volume and acidity of gastric contents, thereby reducing the risk of reflux aspiration. Clear fluids mainly include water, nutritious high-carbohydrate beverages, carbonated beverages, tea, black coffee (without milk) and various residue-free fruit juices, but none of them contain alcohol. There are also requirements for the amount of intake, which should be ≤5ml/kg or the total amount ≤400ml.

“4” Infants and young children can be breastfed 4 hours before anesthesia. Breast milk is rich in lactose and unsaturated fat, which helps infants and young children digest and absorb.

“6” You can eat milk, formula milk, dairy products and starchy solid foods 6 hours before anesthesia. Milk and formula milk have high casein and saturated fat content, which can easily form a large amount of milk lumps in the stomach, which is not conducive to digestion. Starchy solid foods mainly refer to flour and cereal foods, such as steamed bread, bread, noodles, rice, etc., which are mainly divided into carbohydrates, contain some protein, and have low fat content.

“8” If you want to take solid fatty food, you need to do so 8 hours or even longer before anesthesia. Solid fatty food mainly refers to animal fat, meat and fried food. Due to its high fat and protein content and the lack of corresponding digestive enzymes in the stomach, the emptying time in the stomach is significantly prolonged.

Preoperative diet strategies are designed to reduce surgical risks and improve patient comfort and satisfaction. However, it should be noted that these strategies may not be applicable to all situations, so in actual application, doctors need to develop personalized fasting plans based on the patient's specific situation and the type of surgery. Reasonably shorten the preoperative fasting and abstinence time to increase patient comfort and reduce surgical stress. Strengthen communication and cooperation between clinicians, anesthesiologists, nursing staff, patients and their families, work together, do every detail well, and escort patients' "fasting preparations".

Reference Guide:

2016 Guidelines for Perioperative Nutritional Support in Adults

2017 Guidelines for Fasting Before Anesthesia for Adult and Pediatric Surgery

2017 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting

2023 American Society of Anesthesiologists Preoperative Fasting Practice Guidelines

Author: Shanghai Tongji Hospital

Li Wei, Emergency Trauma Treatment Center

Editor: Shanghai Tongji Hospital

Emergency Trauma Treatment Center Yang Xiuxia

Proofreader: Shanghai Tongji Hospital

Li Jun, Institute of Big Health Engineering Management