从禁食到优化：术前口服碳水化合物的代谢 机制、临床获益与麻醉管理应用

From Fasting to Optimization: Metabolic Mechanisms, Clinical Benefits and Anesthesia Management Applications of Preoperative Oral Carbohydrates

摘要: 传统的长时间术前禁食旨在降低麻醉反流误吸风险，但会加剧患者不适、胰岛素抵抗和分解代谢。加速康复外科(ERAS)理念推荐术前口服碳水化合物(POC)作为优化围术期管理的关键措施。本综述旨在系统评价POC的生理基础、临床应用方案、对患者结局的影响及其在麻醉管理中的意义，并讨论其在特殊人群患者中的应用。POC通常在术前夜及术前2~3小时给予特定浓度(如12.5%)的碳水化合物清液。其核心机制在于缓解患者的口渴、饥饿及焦虑感，并通过提供外源性葡萄糖减轻术后胰岛素抵抗，维持代谢稳态和内环境稳定，可能促进胃肠功能恢复。大量证据表明，POC能显著改善患者的主观舒适度，有效减轻术后胰岛素抵抗和高血糖，并可能缩短住院时间，尤其在大型手术中。在安全性方面，遵循指南(术前6小时禁固体，术前2小时饮清液)的POC方案并未增加误吸风险，研究显示其胃排空速率符合要求甚至优于传统禁食，这一现象在糖尿病及肥胖患者中也得到了临床验证。但对于存在严重胃排空延迟(如严重糖尿病胃轻瘫、幽门梗阻)、急诊或困难气道高风险患者需谨慎或避免。结论认为，对于无禁忌的择期手术患者，POC是一项安全有效的ERAS干预措施，能优化围术期生理状态、改善患者体验并促进恢复，麻醉科医生应理解其机制与安全范围并积极推广规范应用。未来研究需关注特殊人群和手术类型的精细化应用。

Abstract: Traditional prolonged preoperative fasting is aimed at reducing the risk of anesthesia-induced reflux and aspiration, but it can exacerbate patient discomfort, insulin resistance, and catabolism. The concept of Enhanced Recovery After Surgery (ERAS) recommends oral administration of carbohydrates (POC) before surgery as a key measure to optimize perioperative management. This review aims to systematically evaluate the physiological basis, clinical application protocols, impact on patient outcomes, and significance in anesthesia management of POC, and discuss its application in special patient populations. POC is typically administered in the preoperative night and 2~3 hours before surgery at a specific concentration (such as 12.5%), such as a carbohydrate solution. Its core mechanism lies in alleviating patient thirst, hunger, and anxiety, and by providing exogenous glucose to reduce postoperative insulin resistance, maintaining metabolic homeostasis and internal environment stability, and possibly promoting gastrointestinal function recovery. A large amount of evidence indicates that POC can significantly improve patient subjective comfort, effectively alleviate postoperative insulin resistance and hyperglycemia, and possibly shorten hospital stay, especially in major surgeries. In terms of safety, the POC protocol following the guidelines (no solid food 6 hours before surgery, clear liquid 2 hours before surgery) does not increase the risk of aspiration. Studies have shown that its gastric emptying rate meets the requirements or even exceeds that of traditional fasting, and this phenomenon has also been clinically verified in diabetic and obese patients. However, for patients with severe gastric emptying delay (such as severe diabetic gastroparesis or pyloric obstruction), emergency or high-risk airway patients, caution or avoidance is necessary. The conclusion is that for patients without contraindications for elective surgery, POC is a safe and effective ERAS intervention measure that can optimize perioperative physiological status, improve patient experience, and promote recovery. Anesthesiologists should understand its mechanism and safety range and actively promote its standardized application. Future research should focus on the refined application in special populations and surgical types.