PDF(Pubmed)
Abstract：
In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century \'nil by mouth after midnight\' had become routine as the principles of the management of \'full stomach\' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.
摘要：
在麻醉的早期，液体的禁食期保持较短。到20世纪中叶，“午夜后不口服”已成为常规，因为“饱腹”紧急情况的管理原则已扩展到包括选择性健康患者。那时候，液体和固体的扣留没有区别。在上世纪末,专业麻醉学机构的建议开始将透明液体的禁食时间减少到2小时。这种禁食时间的减少是基于对透明液体的胃排空迅速的理解，指数，并且与胃的当前填充状态成正比。此外，没有证据表明饮用透明液体与误吸风险之间存在关联.的确,大多数误吸是由于未能识别误吸风险因素并相应调整麻醉技术引起的。相比之下,长时间抽液会引起不适，也可能导致严重的术后并发症。尽管如此,在引入2小时限制20多年后，患者在麻醉前仍禁食12小时，主要是因为组织问题。因此,一些医院决定允许病人在麻醉诱导后2小时内饮用透明液体。精心设计的临床试验应调查这些概念是否安全的患者进行麻醉或程序镇静。重点关注误吸风险和长期禁食的并发症。
