Brands of insulin aspart
Fiasp®, NovoRapid®, Trurapi®
Issues for surgery
Increased risk of post-operative infection and delayed wound healing due to poor glycaemic control if omitted.
Hypoglycaemia if continued during nil by mouth period / in patients undertaking a liver reduction diet (LRD) pre-operatively.
Advice in the perioperative period
Insulin products are classified according to their duration of action, and it is important to understand the type of insulin the patient is on in relation to the advice to be given perioperatively. Confirm with the patient the exact name, strength, dose, frequency, and preparation of insulin(s) that they are using (see Further information).content here
Elective surgery
Omit doses whilst not eating – see table below.
EXCEPT:
- patients on continuous subcutaneous insulin infusion (CSII) – see Insulin – Continuous subcutaneous insulin infusion (CSII) (insulin pump) drug monograph.
- patients undertaking a liver reduction diet pre-operatively – see Patients undergoing surgery that requires liver reduction (LRD).
When reducing insulin doses round to the nearest whole unit.
| Regimen | Day before procedure | Day of procedure (morning procedure) | Day of procedure (afternoon procedure) |
|---|---|---|---|
Multiple daily injections | No dose change | Omit morning dose if no breakfast eaten Check CBG on admission Omit lunchtime dose if not eating and drinking normally | Take usual morning dose with breakfast Omit lunchtime dose if not eating Check CBG on admission |
Patients undergoing surgery that requires liver reduction diet (LRD)
Patients with type 1 diabetes mellitus
An individualised management plan should be formulated with the diabetes specialist team.
Patients with type 2 diabetes mellitus commencing on liver reduction diet (LRD)
Stop regular administration of insulin aspart when LRD commences and monitor CBG closely. If CBG is greater than 15mmol/L give 50% of usual dose of insulin aspart as a rescue or correction dose (see Further information). When reducing insulin doses round to the nearest unit.
Patients with type 2 diabetes mellitus not following a LRD
Follow the advice above for elective surgery.
Patients who receive continuous subcutaneous insulin infusion (CSII) / insulin pump
See Insulin – Continuous subcutaneous insulin infusion (CSII) (insulin pump) drug monograph for details on perioperative management, including practical considerations.
Patients who self-mix two different insulins into one injection
Take as usual on day before operation.
Omit doses of insulin aspart on day of surgery whilst not eating, except for patients undertaking a liver reduction diet pre-operatively – see Patients undergoing surgery that requires liver reduction diet (LRD) above.
Adjust dose of intermediate-acting insulin as outlined in relevant individual monograph.
Emergency surgery
Monitor CBG, ketones, renal profile, and lactate on admission to exclude diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic state (HHS). The advice given above can be applied to patients presenting for emergency surgery; however, it must be remembered that these patients are high risk and are likely to require intravenous insulin infusion; either variable rate intravenous insulin infusion (VRIII), or in the case of DKA or HHS a fixed rate intravenous insulin infusion. Continue to monitor ketones if capillary blood glucose (CBG) greater than 13mmol/mol.
Perioperative considerations
Commence variable rate intravenous insulin infusion (VRIII) perioperatively where indicated and omit insulin aspart during VRIII treatment. Patients on basal-bolus regimens should continue their long-acting insulin at 80% of the usual dose (see Further information). If not usually prescribed long-acting insulin commence at a dose of 0.2 units per kilogram.
Ensure emergency treatment of hypoglycaemia is prescribed i.e. Glucogel® and 20% dextrose. Rapid-acting insulin should also be prescribed.
Post-operative advice
Encourage an early return to normal eating and drinking (as deemed appropriate by the surgical team), facilitating return to the patient’s usual diabetic regimen. Resume usual evening insulin dose if eating a normal meal. If eating a small meal give half usual dose. If not eating, ensure basal component of insulin regimen is still administered – see relevant individual drug monograph.
However, the insulin dose(s) may need further adjusting, as insulin requirements can change due to post-operative stress, infection or altered food intake – monitor CBG levels and seek advice from specialist diabetes team if necessary.
Patients undergoing bariatric surgery
Improved glycaemic control is expected because of reduced calorie intake, early satiety and weight loss following bariatric surgery.
Patients with type 1 diabetes mellitus
Review by the diabetes specialist team post-operatively.
Patients with type 2 diabetes mellitus
Discontinue insulin aspart post-operatively. Blood glucose should be monitored until eating habits and food intake stabilises, if long-acting insulin is recommenced post-operatively see relevant individual drug record. Patients should have their need for ongoing pharmacological management of their diabetes mellitus reviewed by their general practitioner or bariatric surgical team.
Interactions with common anaesthetic agents
Reduction of blood-glucose lowering effect
Substances that may reduce the blood-glucose-lowering effect of insulin include sympathomimetics (e.g. epinephrine / adrenaline).
Interactions with other common medicines used in the perioperative period
Enhancement of blood-glucose lowering effect
Substances that may enhance the blood-glucose lowering effect of insulin and increase susceptibility to hypoglycaemia include sulphonamide antibiotics (e.g. co-trimoxazole).
Reduction of blood-glucose lowering effect
Corticosteroids can reduce the blood-glucose-lowering effect of insulin. Clinically important hyperglycaemia has been seen. Monitor CBG closely when corticosteroids are given to patients with diabetes.
Somatostatin analogues (octreotide and possibly lanreotide) may increase or decrease insulin requirements, but most patients with type 1 diabetes are likely to require a reduction in insulin dose, with some studies suggesting a potential reduction of 50% in patients taking concomitant octreotide. Monitor CBG when somatostatin analogues are given to patients with diabetes.
Further information
Safe prescribing and administration of insulin
Insulin should be prescribed according to National Patient Safety Agency (NPSA) recommendations for safe use of insulin, with the brand name and units written in full.
Patients and nursing staff should be reminded of the importance of rotating injection sites within the same body region to reduce or prevent the risk of cutaneous amyloidosis and other skin reactions; injecting into an affected ‘lumpy’ area may reduce the effectiveness of insulin.
VRIII
Patients with a planned short starvation period (no more than one missed meal in total) should be managed by modification of their usual diabetes medication, avoiding VRIII wherever possible (although VRIII may be necessary in patients with type 1 diabetes mellitus who have not received their long-acting insulin, in patients with type 1 diabetes mellitus who are expected to miss more than one meal, if emergency surgery or in people with poorly controlled diabetes mellitus (HbA1c >69mmol/mol)). Patients with type 2 diabetes mellitus who are expected to miss more than one meal should have VRIII if they develop hyperglycaemia (CBG >12mmol/L).
For patients on basal-bolus regimen, continue long-acting insulin at 80% of usual dose during treatment with VRIII to prevent hyperglycaemia and ketosis on cessation of VRIII, if not usually prescribed long-acting insulin commence at dose of 0.2 units per kilogram. In patients with type 1 diabetes mellitus do not discontinue VRIII unless patient has received alternative subcutaneous insulin within the last 30 minutes.
Liver reduction diet (LRD)
Obese patients often have a large, fatty liver which can cause difficulty for laparoscopic surgery, as the stomach cannot be easily accessed. The LRD typically starts 10 – 15 days prior to surgery and is based on low calories, in particular low carbohydrate and fat. This forces stored glycogen to be released from the liver (plus some water), making it softer, more flexible and easier to move. Due to the reduced calorie and carbohydrate intake, CBG levels will most likely be reduced. Patients are at increased risk of hypoglycaemia when insulin aspart is continued during this period.
References
Centre for Perioperative Care. Guideline for Perioperative Care for People with Diabetes Mellitus Undergoing Elective and Emergency Surgery (updated October 2023). Available at: https://cpoc.org.uk/guidelines-resources/guidelines [Accessed on 23rd February 2024]
Busetto L, Dicker D, Azran C et al. Practical Recommendations of the Obesity Management Task Force of the European Association for the Study of Obesity for the Post-Bariatric Surgery Medical Management. Obesity Facts 2017; 10:597 – 632 doi:10.1159/000481825
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 23rd February 2024]
Summary of Product Characteristics – Novorapid® (insulin aspart) flexpen. Novo Nordisk Limited. Accessed via www.medicines.org.uk 23/02/2024 [date of revision of the text January 2021]
Insulin. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 23rd February 2024]
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed 23rd February 2024]