Diabetes & Surgery — Print Version

Getting Ready

Ask for a morning list spot if possible (less fasting time)
Bring your insulin, injecting equipment, and hypo treatment (lollies, dextrose tablets) to hospital
Check your blood glucose levels more often in the days before surgery
Do not drive to hospital while fasting

Step 2 — Do You Take an SGLT2i Medication?

Are you taking Forxiga, Qtern, Xigduo, Jardiance, Jardiamet, or Glyxambi?

YES — I take one of these

Stop it 3 days before your surgery (day of surgery + 2 days before)
Surgery may be postponed if not stopped in time and ketone levels are raised
Restart only when eating and drinking normally (usually 3–5 days after surgery)

NO — Move on to Step 3.

Step 3 — Do You Take a GLP-1 Medication?

Are you taking Ozempic, Wegovy, Rybelsus, Mounjaro, Trulicity, or Saxenda?

Option A — You've been told to stop it (that's OK):

Weekly (Ozempic, Wegovy, Mounjaro, Trulicity) — stop 1 week before
Daily (Saxenda, Rybelsus) — stop day before
Follow standard fasting. Restart when eating normally.

Option B — It's too late to stop it (ANZCA 2025):

Day before: Clear fluid diet for 24 hours
Day of: Standard 6-hour fast, no SipTilSend
Absence of nausea ≠ empty stomach
If clear fluid diet not completed → tell anaesthetist (gastric ultrasound may be needed)

Ref: 2025 ADS/ANZCA/GESA/NACOS Recommendations

Step 4 — Tablets or Insulin?

TABLETS ONLY (not SGLT2i)

Fasting overnight: Skip your morning tablet. Restart with your evening meal after surgery.
On Metformin + major surgery: Stop Metformin on the day of surgery. Your doctor will check kidney function before restarting.

ON INSULIN — Your instructions depend on the type of insulin and time of surgery. See Step 5.

Step 5 — Insulin Instructions

Morning Surgery

Evening before: Take usual short-acting insulin with dinner. Reduce night-time / long-acting insulin by 50%.
Morning of surgery (fasting): No short-acting insulin. Type 1 patients: get IV access on admission.
After surgery: Check BGL in recovery. If eating by 10am, delay morning insulin and have a late breakfast. Resume normal insulin with evening meal.

Afternoon Surgery

Day before: Take your regular insulin doses as normal.
Morning of surgery: Early breakfast with a reduced dose of insulin (confirmed by your anaesthetist or endocrinologist).
After surgery: Resume insulin when eating and drinking normally. Overnight admission may be needed if blood sugars are unstable.

Dose Adjustments by Insulin Type

Step 6 — On the Day & After Surgery

Insulin Type	Examples	Instructions
Rapid / Short-Acting	Novorapid, Humalog, Apidra, Actrapid, Humulin R	Only take with meals. Skip if fasting.
Long-Acting	Lantus, Levemir, Toujeo	Normal dose morning before. Half dose evening before. Half dose morning of. Normal dose evening after.
Pre-Mixed	Humalin 30/70, NovoMix 30, Penmix	Normal dose morning before. Half dose evening before. One third dose morning of. Normal dose evening after.
Insulin Pump	Any pump device	Continue at your usual basal rate.

Your blood sugar will be checked before, during, and after your procedure
BGL checked in recovery (PACU) and again when you reach the ward
Your anaesthetist will advise nursing staff on restarting your insulin
If you need an insulin drip, you'll be looked after in the Intensive Care Unit

Check Your Blood Sugar Levels Regularly

Check BGL every 2 hours on the day of surgery
Below 5.0 mmol/L — have glucose-containing clear fluids
Above 10.0 mmol/L — drink water or clear diet drinks only
Type 1 patients: never skip insulin completely (risk of diabetic ketoacidosis)

When to Seek Urgent Help

Contact your doctor or hospital immediately if you develop abdominal pain, nausea, vomiting, unusual tiredness, or fast breathing before or after surgery — these may be signs of diabetic ketoacidosis (DKA).

Diabetes & Surgery — Patient Guide

Step 1 — Before Your Procedure