Preoperative fasting for preventing perioperative complications in children

 

Abstract

Background

Children, like adults, are required to fast before general anaesthesia with the aim of reducing the volume and acidity of their stomach contents. It is thought that fasting reduces the risk of regurgitation and aspiration of gastric contents during surgery. Recent developments have encouraged a shift from the standard 'nil-by-mouth-from-midnight' fasting policy to more relaxed regimens. Practice has been slow to change due to questions relating to the duration of a total fast, the type and amount of intake permitted.

Objectives

To systematically assess the effects of different fasting regimens (duration, type and volume of permitted intake) and the impact on perioperative complications and patient well being (aspiration, regurgitation, related morbidity, thirst, hunger, pain, comfort, behaviour, nausea and vomiting) in children.

Search methods

We searched Cochrane Wounds Group Specialised Register (searched 25/6/09), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2 2009), Ovid MEDLINE (1950 to June Week 2 2009), Ovid EMBASE (1980 to 2009 Week 25), EBSCO CINAHL (1982 to June Week 3 2009), the National Research Register, relevant conference proceedings and article reference lists and contacted experts.

Selection criteria

Randomised and quasi randomised controlled trials of preoperative fasting regimens for children were identified.

Data collection and analysis

Data extraction and trial quality assessment was conducted independently by three authors. Trial authors were contacted for additional information including adverse events.

Main results

This first update of the review identified two additional eligible studies, bringing the total number of included studies to 25 (forty seven randomised controlled comparisons involving 2543 children considered to be at normal risk of regurgitation or aspiration during anaesthesia). Only one incidence of aspiration and regurgitation was reported.

Children permitted fluids up to 120 minutes preoperatively were not found to experience higher gastric volumes or lower gastric pH values than those who fasted. The children permitted fluids were less thirsty and hungry, better behaved and more comfortable than those who fasted.

Clear fluids preoperatively did not result in a clinically important difference in children's gastric volume or pH. Evidence relating to the preoperative intake of milk was sparse. The volume of fluid permitted during the preoperative period did not appear to impact on children's intraoperative gastric volume or pH contents.

Authors' conclusions

There is no evidence that children who are denied oral fluids for more than six hours preoperatively benefit in terms of intraoperative gastric volume and pH compared with children permitted unlimited fluids up to two hours preoperatively. Children permitted fluids have a more comfortable preoperative experience in terms of thirst and hunger. This evidence applies only to children who are considered to be at normal risk of aspiration/regurgitation during anaesthesia.

 

Plain language summary

Preoperative fasting for children to prevent complications during surgery

General anaesthetics inhibit the protective reflexes that stop the stomach contents reaching the lungs. In order to prevent the inadvertent inhalation of stomach contents, children are often advised to have nothing to eat or drink from the midnight before surgery. However, the review of trials found that drinking clear fluids up to a few hours before surgery did not increase the risk of regurgitation during or after surgery. Indeed there is an added benefit of a more comfortable preoperative experience in terms of thirst and hunger. Some children are considered more likely to regurgitate under anaesthetic, including those who are obese or have stomach disorders. More research is needed to determine whether these children can also safely drink up to a few hours before surgery.

 

摘要

背景

孩童手術前空腹預防手術期間併發症

孩童與大人相似，在全身麻醉前空腹是為了要降低胃內容物量與酸度. 這樣被認為可以減少手術中病患胃內容物逆流與被吸入肺部的危險.近年來，雖然有比標準的 ‘午夜後不能由口進食與水’ (nilbymouthfrommidnight) 策略寬鬆的方案被提出，但是因為對於所需禁食時間，可食用種類與總量仍有諸多疑問，故相對上在新方案的實行上便顯得慢了許多。

目標

為了能系統性地評估對於孩童而言，不同禁食方案 (時間、種類、以及進食量) 的成效與對於手術併發症以及病人健康狀況 (異物吸入肺部、反胃、相關內科疾病、口渴、饑餓感、疼痛、舒適度、行為、噁心感與嘔吐情形) 的影響。

搜尋策略

作者搜尋了以下的資料庫: Cochrane Wounds Group Specialised Register (搜尋至 25/6/09) 、the Cochrane Central Register of Controlled Trials (The Cochrane Library、Issue 2 2009) 、 Ovid MEDLINE (1950 to June Week 2 2009) 、Ovid EMBASE (1980 to 2009 Week 25) 、 EBSCO CINAHL (1982 to June Week 3 2009) 、the National Research Register其中相關之會議記錄以及所列文獻，並與專家接觸 (討論) 。

選擇標準

針對孩童術前禁食方案的隨機與類隨機對照試驗 (randomised and quasi randomised controlled trials) 。

資料收集與分析

共由3位獨立的作者分別進行資料剖析與試驗品質評估。並與相關作者接觸了解包括併發症等試驗的近一步資訊。

主要結論

這是第一篇最新的回顧文獻 (在增加了2篇額外適合的文章後) 總共收錄了25篇文章 (合計47個隨機對照試驗，總共有可能在麻醉時產生反胃與異物吸入肺部一般風險的孩童2543名) 。其中只有一篇報告了反胃與異物吸入肺部的產生機率。比較術前120分鐘有進食液體的小朋友與在術前完全禁食的小朋友，前者並不會有胃內容物量較多或是胃酸較低的現象發生。此外，這些小朋友較少出現口渴飢餓的情形，感覺也更舒服，而且術前的行為配合也是較佳的。術前進食清流質液體，並不會在臨床上對小朋友胃內容物量與胃酸值造成重大改變。至於與牛奶相關的證據是很稀少的。而進食的液體量似乎也不會影響孩童術中的胃內容物量與胃酸值太多。

作者結論

對於術中胃內容物量與胃酸值，並沒有證據顯示術前禁食至少6個小時的孩童會優於術前2個小時之前仍能進食液體的孩童。

翻譯人

本摘要由成功大學附設醫院林劭潔翻譯。

此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。

總結

針對孩童以術前禁食預防手術期間的併發症。全身麻醉可以抑制人體平常用來阻止胃內容物溢出至肺部的保護性反射動作。所以為了預防術中肺部吸入胃內容物這件事，孩童通常在手術前一個午夜開始會被要求禁食任何食物與液體。但是在回顧統整相關文獻後，卻可發現孩童在手術數小時前進食清流質液體，不僅不會增加術中或是術後胃內容物溢出的比例，甚至在口渴與飢餓方面，會有較佳較舒適的經驗。至於針對某些於麻醉後容易會有胃內容物溢出情形的孩童而言 (如肥胖，或是有胃部疾病的小孩) ，則需要更多的研究來證實，手術數小時前進食清流質液體是安全的。