INSULIN DURING SURGERY

Question 1

What happens to blood glucose during surgery?

Answer 1

• Sugar levels rise due to stress from surgery
• Therefore, it is important to control blood glucose levels
• If a patient is undergoing minor surgery and they already have good glycaemic control, it might not be necessary to give IV insulin and just use their normal insulin dose

Question 2

Elective Surgery (minor procedures with good glycaemic control)

Answer 2

1. Day before surgery
   - Take normal insulin regimen
   - Long-acting insulin dose reduced by 20%
2. During surgery
   - Insulin can be given as normal

Question 3

Elective Surgery (major procedures or poor glycaemic control) Day before

Answer 3

1. Day before surgery
   - Insulin long-acting dose reduced by 20%
2. On day of surgery
   - Continue long-acting reduced dose throughout surgery
   - Give IV Glucose (and NaCl) to prevent hypo
   - Give IV soluble insulin infusion to prevent hyperglycaemia
3. After surgery
   - IV to s/c only if pt is eating and drinking as normal

Question 4

Post surgery

Answer 4

• Convert back to s/c insulin when patient can eat/drink without vomiting
• Basal-bolus regimen: restarted with the first meal - infusions carried on till 30-60 mins after first meal short acting glucose administration
• Long-acting regimen carries on at 20% reduced until patient leaves hospital
• BD regimen: restart at breakfast or evening meal - infusions carried on till 30-60 mins after first meal

Question 5

If someone is taking antidiabetic drugs, when would they require insulin in surgery?

Answer 5

• If fasting time is more than one meal
• Patients with poor glycaemic control
• Risk of renal injury
• Major surgeries

Question 6

If Insulin is required in surgery, which anti-diabetic drugs must be stopped?

Answer 6

• Acarbose
• Meglitinides
• Sulfonylureas
• Pioglitazone
• DPP4-i
• SGLT-2i

Question 7

If insulin is not required, can you give antidiabetic drugs during surgery?

Answer 7

• Yes
• But some dose adjustments needed
• Not ALL can be given though

Question 8

If its a minor surgery, which anti-diabetic drugs must be stopped and why?

Answer 8

1. SGLT-2i (e.g. Canagliflozin)
   - during periods of stress, dehyration, surgery, there is an increased risk of DKA
2. Sulfonylureas (e.g. Gliclazide)
   - Increased risk of Hypo’s
3. Metformin, but ONLY if:
   - They are missing more than one meal
   - -if there is a risk of AKI or eGFR < 60

Question 9

When would
Metformin not be stopped during surgery?

Answer 9

• If only one meal is missed during surgery
• Patient has eGFR > 60

Question 10

Give examples of
“Intercurrent
illnesses”?

Answer 10

• Myocardial infarction
• Coma
• Severe infection
• Trauma