Advice after your nerve block for surgery
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Please refer to specific procedure leaflet (e.g., Endoscopy, Colonoscopy or procedures that require bowel preparation) for more information.
If you use insulin and also take tablets or injection medicines such as GLP‑1 treatments (for example liraglutide, Trulicity®, Ozempic®, or tirzepatide), please also follow the patient instructions leaflet: Advice for people with tablet and GLP-1 or GLP-1/GIP controlled Diabetes undergoing surgery or a procedure requiring a period of starvation.
Before your operation or procedure
Please follow the instructions in the table overleaf “What to do with your tablets or injection before surgery (or procedure).”
Hypo treatment
If you have any symptoms of a low blood sugar such as sweating, dizziness, blurred vision or shaking, test your blood sugar (if you are able to do so). If it is less than 6mmol/L, take 200mls of a rapid acting carbohydrate drink (non-diet, clear liquid, e.g., Lucozade 200mls). Please tell staff at the hospital that you have done this, in case your surgery may have to be delayed/ rearranged for another day.
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After your operation (procedure) your blood sugar will be checked and treatment given if required
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After your operation (procedure) you will be offered food and drink when it is safe / you feel able to eat. If you are eating and drinking normally you should resume taking your usual tablets with your next meal. However, your blood glucose levels may be higher than usual for the next 24 hours. If they don’t settle please contact your health care provider for advice.
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When you get home, if you feel nauseated or vomit and are unable to eat, please refer to the Sick Day Guidance leaflet :
- If you continue to feel unwell for more than 24 hours, please contact your usual health care provider (GP) for advice.
Remember to bring with you to hospital
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A sugary rapid acting carbohydrate drink.
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Blood glucose testing equipment (if you usually monitor your blood glucose). Please note the hospital will monitor your blood glucose.
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Your usual medication.
| Insulins | Day prior to admission (If not using bowel prep) | Day prior to admission/day of admission with bowel prep | Day of surgery / procedure | ||
| Patient for a.m. surgery/procedure with 6am breakfast | Patient for a.m. surgery/procedure Nil by Mouth from midnight |
Patient for p.m. surgery/procedure | |||
|
Once Daily (evening) Lantus®, Abasaglar®, Semglee (Glargine) or Levemir (Detemir®) or Degludec (Tresiba®) or Isophane (Humulin I®) |
Give 80% of dose (Evening prior to surgery or procedure) | No dose adjustment necessary | No dose adjustment necessary | No dose adjustment necessary | |
|
Once daily (morning) Lantus®, Abasaglar®, Semglee (Glargine) or Levemir (Detemir®) or Degludec (Tresiba®) or Isophane (Humulin I®) |
No adjustment necessary | Give 80% of dose and your blood glucose will be checked on admission | Give 80% of dose and your blood glucose will be checked on admission | Give 80% of dose and your blood glucose will be checked on admission | Give 80% of dose and your blood glucose will be checked on admission |
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Twice daily long-acting insulin (morning and evening) Lantus®, Abasaglar®, Semglee (Glargine) or Levemir (Detemir®) or Degludec (Tresiba®) or Isophane (HumulinI®) |
Morning dose will need to stay the same Evening dose will need to be 80% | Give 80% of both doses and your blood glucose will be checked on admissio |
Give 80% of morning dose and your blood glucose will be checked on admission The evening dose remains unchanged |
Give 80% of morning dose and your blood glucose will be checked on admission The evening dose remains unchanged |
Give 80% of morning dose and your blood glucose will be checked on admission The evening dose remains unchanged |
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Twice/Three times daily mixed (biphasic) insulin Novomix 30®, Humulin M3®, Humalog Mix 25®, Humalog Mix 50®, Hypurin Porcine 30/70 mix |
No adjustment necessary |
No adjustment necessary If light diet today reduce to 50% |
50% of your usual morning dose. Your blood glucose will be checked on admission. Resume your usual insulin with your next meal. If eating half/small meal give 50% of usual dose |
50% of your usual morning dose. Your blood glucose will be checked on admission. Resume your usual insulin with your next meal. If eating half/small meal give 50% of usual dose |
50% of your usual morning dose. Your blood glucose will be checked on admission. Omit lunchtime dose. If eating half/small meal give 50% of usual dose. |
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Short, Rapid or ultra-Rapid insulin with meals Actrapid®, Humulin S®, NovoRapid®, Humalog®, Apidra®, Fiasp®, Lyumjev®, Trurapi® |
No adjustment necessary |
No adjustment necessary If eating half/small meal give 50% of usual dose. Omit your morning dose of short/rapid acting insulin if no breakfast. |
Omit your morning dose of short/Rapid acting insulin if no breakfast. Resume your normal insulin with your next meal. If eating half/small meal give 50% of usual dose. |
Omit your morning dose of short/Rapid acting insulin if no breakfast. Resume your normal insulin with your next meal. If eating half/small meal give 50% of usual dose. |
Take your morning dose of short/Rapid acting insulin with breakfast, if eating less see below. Omit lunchtime dose. Your blood glucose will be checked on admission. Resume your normal insulin with your next meal. If eating half/small meal give 50% of usual dose. |
| You should resume taking your normal insulin in the morning after surgery (procedure). However, your blood glucose may be higher than usual for a day or so. | |||||
| Reminder: Levemir® is due to be discontinued in December 2026 and should be removed from this document after this date. | |||||
Contact us
If you have any queries relating to this information, please contact the Diabetes service.
About this information
Service:
Diabetes
Reference:
E/008
Approval date:
16 April 2026
Review date:
1 April 2029
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Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.