Fasting for surgery

  • We ask people to fast before surgery to limit the risk of food being present in the stomach, which could reflux into the airway during the anaesthetic, causing potentially serious complications.

  • Fasting instructions are generally provided by the hospital.

  • Unfortunately , they can be very conservative and result in people being very hungry and dehydrated before surgery.

  • Your anaesthetist is ultimately responsible for “making the call” on acceptable timings, and below are our rules

  • Do not eat any solid food within the 6 hours prior to your surgery time

  • Between 6 hours before and 2 hours before, do not drink anything other than clear fluids (or DEX drinks) 

  • Between 2 hours before surgery and the time you are taken to theatre you may sip water and/or Dex drinks. A ballpark quantity of total fluid is one cup (200 ml) per hour. This is also called “Sip ‘Til Send”.

  • Prescribed medications can be taken at any time (see Medication Advice)

  • if you take the injectible medicine “Mounjaro” , “Wegovy” or “Ozempic” you need special instructions, please see the next section.

If you don’t know your surgery time, you can use the admission time given by the hospital. This is often only texted to you after 3pm on the day prior to surgery.

Clear Fluid Fasts - patients on injectable medications

If you have taken Mounjaro, Wegovy or Ozempic in the last 6 weeks you will need special instructions on fasting prior to surgery. This is due to the slowing effects on gastric emptying time that these medications may induce.

In then 24 hours before your admission time, you may consume only clear fluids, with no solids permitted.

Examples of permitted diet:

  • clear jelly

  • clear broth

  • clear fruit juice - no pulp

  • black tea or coffee

  • clear ice blocks

  • Dex or sports isotonic drinks

Exampled of not permitted diet:

  • dairy products

  • cream soups

  • foods with visible solids or pulp (e.g. noodles in soup, orange juice)

If you have any questions please don’t hesitate to ask the office. If you feel you may have made a mistake please inform your anaesthetist as soon as possible.