Diabetes

Type II

Surgical stress may result in cortisol release and hyperglycaemia. Peri-operative glycaemia also occurs as a result of glycogenolysis, inhibition of glucose uptake, and decreased insulin release. Therefore, hyperglycaemia and ketosis may result in diabetic patients ^{1 – 3}. In addition to the above factors, inactivity and decreased calorific intake may affect blood glucose levels during the peri-operative period. Therefore, it is important to regularly monitor blood glucose levels and in some circumstances to utilise dextrose and insulin infusions.

Other factors that must be born in mind with diabetic patients during gynaecological oncology surgery are as follows;

Patients with diabetes are at an increased risk of coronary artery disease and have a high rate of silent myocardial ischaemia and infarction ⁴. Therefore, an ECG should be obtained preoperatively in all patients as well as a thorough cardiac evaluation.
Hypoinsulinaemia may impair wound healing due to impaired blood supply from microangiopathy ⁵.
Hyperglycaemia results in an impaired inflammatory respose, multifactorial leukocyte dysfunction and alterations in cellular and humoral immunity. This is related to an increased risk of post-operative infections. As a result it is important to adhere to pre-operative antimicrobial prophylaxis regimens (see relevant section); to keep careful watch for signs of post-operative infection; and to have a low threshold in treating suspected infections ⁶.

As a result of all the above factors it is essential that diabetic patients scheduled for gynaecological oncology surgery have a thorough pre-operative assessment and careful management utilising a multidisciplinary approach.

Key professionals involved in the multidisciplinary approach to the management of peri-operative patients with diabetes scheduled for gynaecological oncology surgery include;

Gynaecological oncologist
Anaesthetist
Diabetologist
General practitioner
Diabetic nurse specialist

Pre-operative assessment of diabetic patients prior to gynaecological oncology surgery should include;

Assessment of glycaemic control (HbA1C; reference range 3.6 – 5.9%)
In patients with sub-optimal glycaemic control liason with the diabetic team is required. It may be necessary to convert long-acting drugs to those with a shorter action to reduce the risk of hypoglycaemia.
Aim to perform surgery on the morning list if possible.
Liaise with anaesthetist.

Type II

PATIENTS WITH TYPE 2 DIABETES MELLITUS

Surgery anticipated to be of short duration.

This includes patients in whom starvation of less than 12 hours is anticipated

Well controlled Type 2 diabetic patients undergoing minor surgery only require close glycaemic monitoring (1 – 2 hourly).

Poorly controlled Type 2 diabetic patients, or those undergoing emergency surgery, should be treated as for insulin treated or dependent diabetic women.

Omit oral hypoglycaemic agents on the morning of the operation.
Patient should be nil by mouth according to policy (see relevant section).
Site intravenous cannula.
Monitor blood glucose 1 – 2 hourly immediately prior and during the period patient is fasted; on return from theatres and 2 hourly thereafter.
If blood sugar > 9 mmols on BM stick, administer Human Actrapid 4 units I/V.
Restart oral hypoglycaemics with evening meal.
Patient to monitor own blood sugars when appropriate or on discharge.

Surgery anticipated to be of long duration.

This included patients in whom starvation of more than 12 hours is anticipated.

Omit oral hypoglycaemic agents on the morning of the operation.
Patient should be nil by mouth according to policy (see relevant section).
Site intravenous cannula.
Immediately patient is fasted an intravenous sliding scale of 5% dextrose and soluble insulin should be commenced (see sliding scale).
Blood sugars to be measured hourly and the infusion rate titrated accordingly.
If insulin does not require changing after 4 hours, BM monitoring can occur 2 hourly and then 4 hourly after another 4 hour period. Hourly monitoring must be recommenced after every adjustment to the sliding scale is required.
The 5% dextrose and sliding scale of soluble insulin should continue until eating and drinking is established.
Oral hypoglycaemic agents to be recommenced with first meal.
IV sliding scale to be stopped 1 hr after hypoglycaemic agents ingested.
If glycaemic control poor following recommencement of oral therapy, bolus insulin doses may be used.
Patient to monitor own blood sugars when appropriate or on discharge.

Type II

PATIENTS WITH TYPE 1 DIABETES MELLITUS OR TYPE 2 TREATED WITH INSULIN

Surgery anticipated to be of short duration

This includes patients in whom starvation of less than 12 hours is anticipated

Usual insulin and meal the evening prior to surgery or commencement of bowel preparation protocol (see bowel preparation protocol).
Surgery on morning list if possible.
Patient should be nil by mouth according to hospital policy (section 2.4.11).
Omit morning insulin on day of surgery.
Site intravenous cannula.
IV 5% dextrose and soluble insulin sliding scale to commence.
Blood sugars to be measured hourly and the infusion rate titrated accordingly.
If patient able to eat lunch on return give 8 – 10 units of soluble insulin beforehand.
Usual dose of insulin to be given with the first meal.
Stop IV sliding scale and 5% Dextrose half an hour after insulin given with first meal.

Surgery anticipated to be of long duration

This included patients in whom starvation of more than 12 hours is anticipated.

In these patients a continuous infusion of insulin and glucose (ideally with potassium) is required. Patients undergoing bowel surgery may require lower amounts of insulin and a variety of regimens may be required in women who require nutritional support.

These women should ideally be identified in the pre-admissions clinic.

The day prior to surgery these women should be reviewed by the following people;

Anaesthetic team
Endocrinology team
Diabetes Nurse Specialist

Type II

Insulin Sliding Scale

An example of an insulin sliding scale

Insulin sliding scales should be charted on the hospital ‘Five Day Diabetic Treatment Sheet’.
50 iu Human Actrapid should be made up to a volume of 50ml with Normal Saline.
Infusion rates should be altered according to capillary glucose levels according to the following regimen;

BM glucose Infusion rate

0.0 – 4.0 mmol/l 0.5 ml / hour

4.1 – 7.0 mmol/l 1.0 ml / hour

7.1 – 11.0 mmol/l 2ml / hour

11.1 – 17.0 mmol/l 4ml / hour

17.1 – 27.0 mmol/l 7ml / hour

>27.0 mmol/l 10ml / hour

Type II