Gastric Residual Volumes in Infants Fed at 4 and 6 Hours Prior to General Anaesthesia

Traditional fasting guidelines of 6 hours for formula milk may be unnecessarily long. In practice, children also tend to be fasted for longer than the guidelines advise, as they may not always feed on cue, and delays in the hospital can occur on the day of surgery. Prolonged fasting in young children and infants is less well tolerated than in adults and can lead to hunger, dehydration and low blood sugar, as well as distress for the child and parents. We know from previous research in smaller babies that after a formula feed, the stomach empties by half in around 80 minutes, and empties completely by around 3 hours. The investigators want to find out if young children and infants who are fed with formula milk 4 hours prior to an anaesthetic have similar levels of stomach contents at the time of their anaesthetic as those who are fed at 6 hours. The investigators will carry out a clinical trial where children are randomised into 2 groups. Parents of children in Group 1 will be asked to offer a formula feed to their child 6 hours prior to the planned start time of their anaesthetic. Parents of children in Group 2 will be asked to offer a formula feed to their child 4 hours prior to the planned start time of their anaesthetic. Prior to having their anaesthetic a study team member will perform an abdominal ultrasound scan to check and record antral cross sectional area. Once asleep, gastric aspiration will be performed via naso-gastric tube. Volume, colour and pH of the fluid will be measure The volume and acidity of any stomach contents will be compared between group 1 and group 2.