Ultrasound assessment of gastric emptying time after intake of clear fluids in children scheduled for general anesthesia – A prospective observational study.
This is small prospective study examining the effect of clear fluid intake on gastric antral area (GAA), which is used to represent gastric emptying. 26 children on elective surgical lists were recruited at a single university hospital in Germany. They had an initial ultrasound to measure their gastric antral area. The children were given either clear fluid or fruit juice (approximately 5ml/kg – median 4.7ml/kg, range 1.8-11.8ml/kg) and had serial ultrasounds to measure GAA. GAA increased initially before returning to pre-fluid levels between 30 and 45 minutes.
Many paediatric centres have made changes towards a shorter fasting time for clear fluids from two hours to one hour. This study attempts to give scientific evidence towards this decision. It uses a sensible and easy to follow method.
The authors acknowledge the small number of participants would make it difficult to find any potential complications of fluid intake, so it uses GAA as a surrogate marker. The small number of participants would still allow the study authors to detect a 7.5cm2 increase in GAA (to a 90% statistical power), although the significance of this measurement is not clear. The amount of fluid taken does vary from 1.8 to 11.8ml/kg.
I feel this study does support the change that many paediatric centres have made towards a 1 hour fasting regime for clear fluids, however the initial increase in GAA may suggest that free fluids up until theatre is not the safest practice.
Reviewed by Patrick Cowie