Impact of liberal preoperative clear fluid fasting regimens on the risk of pulmonary aspiration in children (EUROFAST)
An international prospective cohort study
British Journal of Anaesthesia
Submitted September 2025 by Dr Meghan Cooney
Read by 29 Journal Watch subscribers
Overview
The EUROFAST (European Preoperative Fasting Audit) project demonstrated that more liberal clear fluid fasting (≥1 hour) before anaesthesia in children is non-inferior to the more traditional ≥2 hour interval and does not increase the risk of pulmonary aspiration.
Pulmonary aspiration is a rare event in children, and thus a very large sample size is needed to provide reassurance regarding the safety of updates to fasting regimens.
This project set out to compare the risk of pulmonary aspiration with regard to three different clear fluid fasting regimens; sip-til-send, ≥1 hour and ≥2 hours. The allocation to these groups was by intention to treat, not actual clear fluid fasting times.
Methods
Prospective multicentre cohort study that began in Sweden and expanded to an international cohort (beyond Europe).
For other aspects of fasting, an interval of ≥6 hours was required for solid food, ≥4 hours for breastmilk or formula.
This study did not collect actual fasting times for every patient included: this was only assessed for patients who had an aspiration event. The groups are allocated according to each institution’s fasting protocol.
Results
This study included 306, 900 anaesthetic procedures from 31 centres in patients 0-16 years old:
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Sip til send 34,028
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≥1 hour 251,021
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≥2 hour 21,851
The incidence of aspiration for each group was 1.83 vs 0.68 vs 1.18 per 10,000 patients for ≥2 hour, ≥1 hour and sip til send respectively. When combined together, sip til send and ≥1 hour clear fluid fasting protocols were noninferior to ≥2 hour clear fluid fasting in terms of confirmed aspiration and regurgitation with symptoms and escalation of care. This audit may not be adequately powered to definitively declare that ‘sip til send’ does not have a higher rate of aspiration/regurgitation events compared with more traditional fasting protocols.
There were 420 registered aspiration events; 286 categorised as transient (68%), 94 requiring escalation of care (22%) and 40 leading to post-operative intensive care (9.5%). There were no reported deaths, cardiac arrests or aspirations leading to brain damage. Only 18 children with <1 hour actual clear fluid recorded fasting times were involved in any kind of aspiration event, and none of these required intensive care.
This study was not designed to detect risk factors for aspiration, but it remains interesting to see that gastrointestinal anatomical and mobility disorders were implicated in 28% and 18% of these cases, respectively. Emergency surgery and comorbidities were also associated with aspiration. These risk factors are similar to those found in existing literature.
Discussion
This study did not collect actual fasting times for every patient included: this was only assessed for patients who had an aspiration event. Whilst analysis of exact fasting times would have advantages, this study is able assess according to institutional fasting protocols which may reflect a more ‘real life’ approach.
A limitation of this study is that it relied upon anaesthetists to report cases of aspiration or regurgitation, leading to reporting bias (with a very high incidence reported at one particular centre). Whilst its strengths include large case numbers and geographically diverse populations, there is potential for confounding factors due to differences in anaesthesia practice between different centres and clinicians.
Take Home Messages
This study significantly reinforces existing literature that shorter clear fluid fasting intervals prior to anaesthesia do not increase the risk of aspiration/regurgitation.
Importantly, in the rare instances where aspiration or regurgitation events occurred in children, there was no significant morbidity of mortality, although a portion required escalation of care.
This paper supports transition to more liberal clear fluid fasting protocols for children undergoing anaesthesia.
