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SPECIFIC PATIENT INFORMATION

Diabetes and anaesthesia

Having diabetes requires some additional planning before your procedure, particularly while you are fasting. Careful management of your blood glucose levels, food and fluid intake, and diabetes medicines helps keep you safe before, during and after your procedure.

The information below explains what to do while fasting, how to monitor your blood glucose, what to do if your blood glucose is low, and how to manage your diabetes medicines before and after your procedure.

Please include the name, dose and how often you take each medicine when completing your pre-operative questionnaire. This helps me provide the correct instructions for your procedure.

If you are unsure what to do with any of your diabetes medicines before your procedure, please contact me for advice.

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General advice for diabetes

Having diabetes requires some additional planning when you are fasting for a procedure. The aim is to keep your blood glucose at a safe level while avoiding food and managing your usual diabetes medications.

01

While you are fasting

Follow the fasting instructions provided for your procedure.

You may continue to drink clear fluids during the permitted clear-fluid period. Avoid drinks containing milk or other solids.

If you have been given different fasting instructions—for example, because you take a GLP-1 medication—please follow those instructions instead.

03

If your blood glucose is low

If your blood glucose is low while you are fasting, treat the low blood glucose rather than continuing to fast without treatment. Use your usual treatment for low blood glucose, choosing a clear glucose-containing drink where appropriate. Recheck your blood glucose after treatment.

If you need to treat a low blood glucose level while fasting, please let us know as soon as you arrive at the hospital.

05

Restarting your medicines

Your diabetes medications can usually be restarted once you are eating and drinking normally after your procedure, unless you have been given different instructions.

If you are unsure when to restart any of your diabetes medications, please contact me or your treating team for advice.

02

Monitor your blood glucose

If you normally check your blood glucose level (BSL), continue to monitor it while you are fasting.

Check your BSL before leaving home and more frequently if you feel unwell or have symptoms of low blood glucose.

04

Managing your diabetes medications

Some diabetes medications can be continued until the day before your procedure, while others need to be stopped earlier or require special fasting instructions. The Your diabetes medications section below provides instructions for the different types of diabetes medication.

Please do not make additional changes to your diabetes medicines unless instructed to do so.

Your diabetes medications

Diabetes medications need to be managed carefully when you are fasting for a procedure. The instructions below explain what to do with the most common types of diabetes medication. Find the medication you take and follow the instructions for your medication group.

  • Common insulin medications include:

    Long-acting insulin

    • Lantus / Optisulin — insulin glargine

    • Toujeo — insulin glargine

    • Levemir — insulin detemir

    • Tresiba — insulin degludec

    Short or rapid-acting insulin

    • NovoRapid — insulin aspart

    • Fiasp — insulin aspart

    • Humalog — insulin lispro

    • Apidra — insulin glulisine

    • Actrapid — human insulin

    Before your procedure

    Your insulin instructions depend on the type of insulin you use and whether your procedure is in the morning or afternoon.

    Long-acting insulin is generally continued at the usual dose, unless you have been given different instructions.

    If you use rapid- or short-acting insulin with meals, these doses are generally withheld while you are fasting.

    If you use an insulin pump, the basal insulin infusion is generally continued, although the rate may need to be adjusted.

    Please follow the individual insulin instructions provided to you. Do not stop all insulin simply because you are fasting.

    More information on insulin →

  • Common medications in this group include:

    • Jardiance — empagliflozin

    • Forxiga — dapagliflozin

    • Steglatro — ertugliflozin

    Before your procedure

    If you are staying overnight in hospital or taking bowel preparation, stop your SGLT2 inhibitor 3 days before your surgery or procedure.

    SGLT2 inhibitors can increase the risk of diabetic ketoacidosis (DKA) during fasting, illness and around the time of surgery. DKA is a serious complication of diabetes that requires urgent medical treatment.

    Importantly, when taking an SGLT2 inhibitor, DKA can occur even when your blood glucose level is normal or only mildly elevated.

    More information about SGLT2 inhibitors →

  • Common medications in this group include:

    • Diabex — metformin

    • Diaformin — metformin

    • Formet — metformin

    • Metex — metformin

    Before your procedure

    Continue taking metformin as usual until the night before your procedure.

    Do not take metformin on the morning or day of your procedure.

    Jardiamet and Xigduo contain an SGLT2 inhibitor as well as metformin. If you take one of these medications, do not follow the metformin-only instructions. Because they contain an SGLT2 inhibitor, they need to be stopped 3 days before your surgery or procedure.

  • Common medications in this group include:

    • Ozempic / Wegovy — semaglutide

    • Mounjaro — tirzepatide

    • Trulicity — dulaglutide

    • Victoza / Saxenda — liraglutide

    • Rybelsus — semaglutide tablets

    Before your procedure

    Do not stop your GLP-1 medication before your procedure.

    If you are taking a GLP-1 medication, you will need to fast from solid food for 24 hours before your procedure. This is because these medications can slow the emptying of your stomach.

    Please read the detailed fasting instructions on the GLP-1 medications before surgery page and follow these instructions carefully.

    GLP-1 medications before surgery →

  • Common medications in this group include:

    • Diamicron — gliclazide

    • Amaryl — glimepiride

    • Januvia — sitagliptin

    • Trajenta — linagliptin

    • Galvus — vildagliptin

    • Onglyza — saxagliptin

    • Actos — pioglitazone

    Before your procedure

    Continue taking these medications as usual until the day before your procedure.

    Do not take your usual morning dose on the day of your procedure while you are fasting.

    If your medication contains more than one diabetes medication, please check the Combination diabetes medications section, as different instructions may apply.

  • Combination diabetes medications contain two or more diabetes medications in a single tablet.

    Common examples include:

    • Jardiamet — SGLT2 inhibitor + metformin

    • Xigduo XR — SGLT2 inhibitor + metformin

    • Janumet — sitagliptin + metformin

    • Galvumet — vildagliptin + metformin

    • Trajentamet — linagliptin + metformin

    Before your procedure

    If you take a combination diabetes medication, it is important to know all of the active ingredients it contains. One component may need to be stopped before your procedure even if another component would normally be continued.

    In particular, some combination tablets contain an SGLT2 inhibitor. These medications require special management before surgery or procedures requiring fasting.

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