Preprocedural management of insulin for adults with type 2 diabetes

For adults with type 2 diabetes using insulin, it is important to achieve and maintain glycaemic targets during the periprocedural period. All patients with type 2 diabetes who are fasting before a procedure should be given written instructions (including emergency contact numbers) to guide insulin management and blood glucose concentration monitoring. General principles of management for a patient with type 1 diabetes who is fasting are given in Instructions for patients with type 1 diabetes who are fasting before a procedure and may apply for patients with type 2 diabetes using insulin.

Patients should continue their usual subcutaneous insulin regimen the day before a procedure, and insulin dosage should be adjusted the day of the procedure; see Suggested subcutaneous insulin management on the day of a procedure for adults with type 2 diabetes. Patients should check their blood glucose concentration every 1 to 2 hours until they are admitted for the procedure. They should not drink glucose-containing fluid except to treat hypoglycaemia.

Patients with type 2 diabetes (particularly if using insulin or taking a sulfonylurea) who are fasting before a procedure are at risk of hypoglycaemia and should not drive.

Table 1. Suggested subcutaneous insulin management on the day of a procedure for adults with type 2 diabetes
Usual insulin regimen: Evening basal insulin only Morning basal insulin only Multiple daily injection (basal–bolus) Fixed-dose combination (biphasic premixed or coformulation) insulin Intermediate-acting insulin twice daily with rapid- or short-acting insulin bolus doses for meals
Evening basal insulin only
Insulin adjustment for a morning procedure [NB1]	Insulin adjustment for an afternoon procedure [NB1]
Give usual dose of basal insulin [NB2].	Give usual dose of basal insulin [NB2].
Morning basal insulin only
Insulin adjustment for a morning procedure [NB1]	Insulin adjustment for an afternoon procedure [NB1]
Give usual dose of basal insulin [NB2].	Give usual dose of basal insulin [NB2].
Multiple daily injection (basal–bolus)
Insulin adjustment for a morning procedure [NB1]	Insulin adjustment for an afternoon procedure [NB1]
Give usual dose of basal insulin [NB2]. Omit breakfast rapid- or short-acting insulin bolus dose. Give usual lunchtime rapid- or short-acting insulin bolus dose if eating. Give usual evening-meal rapid- or short-acting insulin bolus dose if eating.	Give usual dose of basal insulin [NB2]. Give half usual breakfast rapid- or short-acting insulin bolus dose. Omit lunchtime rapid- or short-acting insulin bolus dose. Give usual evening-meal rapid- or short-acting insulin bolus dose if eating.
Fixed-dose combination (biphasic premixed or coformulation) insulin
Insulin adjustment for a morning procedure [NB1]	Insulin adjustment for an afternoon procedure [NB1]
Give half usual morning insulin dose. Give usual lunchtime insulin dose if eating. Give usual evening insulin dose if eating.	Give half usual morning insulin dose. Omit lunchtime insulin dose. Give usual evening insulin dose if eating.
Intermediate-acting insulin twice daily with rapid- or short-acting insulin bolus dose for meals
Insulin adjustment for a morning procedure [NB1]	Insulin adjustment for an afternoon procedure [NB1]
Give usual morning intermediate-acting insulin dose. Omit breakfast rapid- or short-acting insulin bolus dose. Give usual lunchtime rapid- or short-acting insulin bolus dose if eating. Give usual evening insulin doses if eating.	Give usual morning intermediate-acting insulin dose. Give half usual breakfast rapid- or short-acting insulin bolus dose. Omit lunchtime rapid- or short-acting insulin bolus dose. Give usual evening insulin doses if eating.
Note: BGC = blood glucose concentration NB1: If the patient has not resumed eating normally after the procedure, the insulin dose and regimen need review. NB2: If the patient’s glycated haemoglobin (HbA1c) is 53 mmol/mol (7%) or less, recent fasting BGCs have been less than 5 mmol/L, or the patient has hypoglycaemia unawareness, then temporarily reduce the basal insulin dose to 80% of the usual dose (20% less than usual) while fasting.