Short-acting: Actrapid®, Humulin® S, Insuman® Infusat, Insuman® Rapid, Fiasp® [insulin aspart], NovoRapid® [insulin aspart], Apidra® [insulin glulisine], Humalog® [insulin lispro]
[This monograph covers continuous infusion of insulin – for THREE, FOUR or FIVE daily injections see separate monograph as advice is dependent on the regime used]
Issues for Surgery
Hypoglycaemia if continued during nil by mouth period.
Increased risk of post-operative infection and delayed wound healing due to poor glycaemic control if discontinued.
Advice in the Perioperative period
The patient’s specialist pump Diabetes Team should be involved in the planning for elective surgery. The patient should bring all necessary pump supplies into hospital with them.
Advice is dependent on the type of surgery and number of meals likely to be missed: -
It should be assumed that during an elective hospital admission, the patient will take responsibility for the CSII pump during their stay, except for the period of reduced consciousness during surgery when another allocated healthcare professional must take on that obligation.
A concise management plan, detailing the planned continuation/discontinuation of the pump during surgery should be documented in the medical notes; together with signed consent of the patient1.
The specialist Diabetes Team should be contact to review the patients and formulate an individual plan. Continuation of CSII will depend on whether the patient is well enough to manage it on his or her own and the type of procedure/duration of fasting as stated above for Elective Surgery. An assessment of the patient’s blood glucose, blood/urine ketones, + / - venous/arterial pH is advised2.
Current manufacturers guidelines state that CSII pumps must not be exposed to screening radiological procedures (CT, MRI, X-Ray)1, 2. However, this advice is probably based on lack of evidence rather then evidence of harm. US guidance advocates that the pump can remain in place for X-Ray / CT, ensuring that the pump is covered by the lead apron3. Trusts should adopt their own guidelines2.
Where CSII is discontinued for a radiological investigation, it should be immediately reconnected. CSII can be safely suspended / removed for up to an hour at a time without needing alternative insulin2.
Where the pump has been discontinued, the patient’s pump should be restarted as soon as possible post-operatively when they are able to manage it themselves.
Where VRIII has been used, this must be continued for 60 minutes alongside the pump once it has been restarted with hourly BM checks2.
If the patient is unable to manage their CSII post-operatively and they are not nil by mouth (NBM), a basal-bolus regimen is preferable to VRII2. This should be discussed with the specialist Diabetes Team.
Interaction(s) with Common Anaesthetic Agents
Reduction of Blood-Glucose Lowering Effect
Substances that may reduce the blood-glucose-lowering effect include sympathomimetics (e.g. epinephrine / adrenaline)4.
Interaction(s) with other Common Medicines used in the Perioperative Period
Enhancement of Blood-Glucose Lowering Effect
Substances that may enhance the blood-glucose lowering effect and increase susceptibility to hypoglycaemia include sulphonamide antibiotics (e.g. co-trimoxazole)4.
Reduction of Blood-Glucose Lowering Effect
Corticosteroids can reduce the blood-glucose-lowering effect of insulin4. Clinically important hyperglycaemia has been seen5. Monitor blood glucose concentrations closely when corticosteroids are given to patients with diabetes5.
Octreotide may increase or decrease insulin requirements4 but most patients with type 1 diabetes are likely to require a reduction in insulin dose6.
Continuous subcutaneous (s/c) insulin infusion (CSII)
This is a continuous s/c infusion of insulin (usually in the form of a rapid-acting insulin or soluble insulin), delivered by a programmable pump. It is designed to mimic physiological insulin delivery over 24 hours with basal and bolus insulin infusions of rapid-acting insulin analogue7. They are currently used by 10-15% of the people with diabetes (mainly type 1)2.
Safe Prescribing 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 full1.