Real fasting times and incidence of pulmonary aspiration in children: Results of a German prospective multicentre observational study


  • A prospective multi-centre observational study designed to give guidance to a proposed change to the national fasting guidelines for children in Germany (which stand at 6hours for solids, 4hrs for breast and formula, and 2hrs for clear fluids)
  • 3324 patients undergoing elective or emergent surgical, diagnostic or investigative procedures across ten German centres were enrolled between October 2018 and May 2019
  • Patient demographics, real fasting times for “large” and “light” meals, anaesthetic, surgical procedures and occurrence of regurgitation or pulmonary aspiration were documented using a standardised case report form, reporting medians and incidence
  • Of note actual fasting guidelines were at the discretion of the institutions. Three followed a 6/4/2 rule, four a 6/4/1 rule and three a 6/4/0 rule.


  • Emergencies made up 8.8% of all surgery, with elective ENT the most common operative type. Anaesthesia induction was mostly intravenous, 3.7% a RSI, using pre-dominantly LMA’s
  • Real fasting times for large meals was a median of 14hrs [12.2-15.6], for light meals 9hrs

[5.6-13.3], for formula 5.8hrs [4.5-7.4], for breast milk 4.8 [4.2-6.3] and for clear oral fluids 2.7

hours [1.5-6]

  • There were 11 cases of regurgitation (0.33%), 4 cases of suspected aspiration (0.12%) and 2 cases of confirmed aspiration (0.06%) of gastric juice. There were no reported cases of aspiration of solids/semisolids/milk. 5/11 cases of aspiration were in emergencies. Aspiration was most likely to occur at induction.
  • All of the 17 children with suspected regurgitation/aspiration events were able to be extubated. Respiratory symptoms were temporary and there was no escalation of care beyond a PACU stay.


This large observational study is broadly applicable, serves to remind us that prolonged fasting beyond guidelines remains commonplace, and re-assuringly reinforces that aspiration is uncommon and associated with temporary sequelae. These findings are hardly new, but should be viewed in the context of a good quality approach to guiding the modification of national guidelines and this study contributes to a body of evidence. It is noted that adherence to pre-operative fasting guidelines is a complex matter influenced by many factors, and further the interaction between fasting and regurgitation/aspiration events is multifactorial and individually variable. They conclude that revised guidelines should be liberalised to 1hr for clear fluids and 4hrs for “standardised light meals”. This is similar to our institutional guidelines, although we make no distinction on what constitutes a light meal. I expect that such a distinction might be needlessly complex in our local environment. It is worth noting that the study population was subject to a variety of local guidelines, which varied from liberal to conservative, and the population size is too small to evaluate any association between real fasting times and aspiration.

Reviewed by: Dr Jesse Chisholm