DIVISION OF MEDICINE
Guidelines for management of patients
with diabetes undergoing surgery
July 2008
PJH
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Guidelines for management of patients with diabetes undergoing surgery
Patients with diabetes undergoing surgery
Close co-operation between medical and nursing staff is essential to the preand post-operative care of patients with diabetes in order to minimise
complications and maximise comfort for the patient. A combined approach
with sharing of information and findings following the initial assessment is
vital especially in the anxious or distressed patient newly admitted to hospital.
Points to consider when making the initial assessment
1. How long has the patient had diabetes?
2. What treatment is the patient on to control glucose?

Insulin alone or insulin and tablets?

Tablets alone?

Diet alone?
3. How does the patient normally monitor their diabetes?
4. Does the patient attend a diabetes clinic in a hospital or is it managed by
the GP?
5. Is there any evidence of complications of diabetes pre-operatively?

Heart disease e.g. angina, myocardial infarction.

Kidney disease e.g. nephropathy, renal artery stenosis, renal failure.

Eye disease e.g. retinopathy, cataracts.
6. Are there any problems directly relating to their diabetes?

Hyperglycaemia or hypoglycaemia and time of day it tends to occur.

Recent illness with nausea and vomiting.

Electrolyte imbalance

Autonomic neuropathy causing diarrhoea, gastroparesis or postural
hypotension.
7. Pre-operative investigations – minimum requirements are as follows:

Urine for ketones

Urea and electrolytes

Blood glucose
July 2008
PJH
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Guidelines for management of patients with diabetes undergoing surgery
Type 2 Diabetes Mellitus
(Non-Insulin Dependent Diabetes Mellitus)
Patient with Type 2 diabetes undergoing minor surgery or procedure
1. Plan the procedure for early next day i.e. first on the list if possible. If the
patient cannot be put on the morning list then they should be first on the
afternoon list.
2. Any patient on an afternoon list should be admitted before 10am at the
latest to ensure that they have stable glucose control pre-operatively. It
may be possible for the patient to have breakfast and take their usual oral
hypoglycaemic agents assuming they do not need to be fasting for the
procedure and that they are expected to be able to eat an evening meal.
3. Most oral hypoglycaemic agents (OHA) are taken with food. If a meal is
missed the OHA is usually omitted.
4. After the procedure give the OHA with the first post-operative meal.
5. Some sulphonylureas (a class of OHA) have a long 1/2 life e.g.
Chlorpropamide, Glibenclamide and Glimepiride. Chlorpropamide should
be stopped at least 36 hours before surgery. Consider the use of glucose
infusion to prevent hypoglycaemia pre- and post-operatively.
6. Check the patient’s glucose immediately before, immediately after and
then 4 hourly (before meal times) until the patient is eating and drinking
normally.
Patient with Type 2 Diabetes undergoing major surgery
1. Plan the procedure for early next day first on the list if possible. If not on
morning list then first on afternoon list.
2. Omit the OHA on the morning of the procedure. See above for long acting
OHAs.
3. The majority of patients will require a glucose/insulin infusion. This should
be started pre-operatively and continued post-operatively until the regular
medication can be recommenced.
4. Subcutaneous insulin may be required short term post-operatively.
NB See enclosed glucose/insulin infusion regimen (p. 7-9)
July 2008
PJH
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Guidelines for management of patients with diabetes undergoing surgery
Patient with Type 2 Diabetes undergoing emergency surgery
1. Careful assessment is needed, management will depend on:

Type of oral hypoglycaemic agent (OHA) taken by the patient.

Time of the last dose of OHA.

How well the glucose was controlled on admission.

Presence of ketones in the urine (indicates insulin deficiency).

Severity of illness and type of surgery required.
2. Following assessment the management options include:

No specific action other than monitoring glucose. Possibly avoid
glucose containing intravenous fluids if glucose already slightly
elevated (> 6 but < 10 mmol/l).

Intravenous 5% glucose if recently ingested OHA, starting at 100
mls/hr. Can use 10% glucose at initial rate of 50mls/hr if trying to
avoid fluid overload.

Glucose/insulin infusion regimen if glucose consistently elevated e.g.
>10mmol/l.
NB See enclosed glucose/insulin infusion regimen (p. 7-9)
Delayed recovery will require reassessment and may
require further action
e.g. conversion to a glucose/insulin infusion if the patient remains
nil by mouth.
July 2008
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Guidelines for management of patients with diabetes undergoing surgery
Type 1 Diabetes Mellitus
(Insulin Dependent Diabetes Mellitus)
and
Insulin treated Type 2 Diabetes
Insulin treated patient undergoing minor surgery or procedure e.g.
barium meal, endoscopy (no general anaesthetic)
1. The patient should have the normal subcutaneous insulin doses on the
day prior to the minor surgery or procedure.
2. Plan the procedure for early next day i.e. first on the morning list if
possible. If unable to put on morning list put first on afternoon list.
3. Following an overnight fast delay the morning insulin dose on the day of
surgery until late breakfast or lunch if on a morning list.
4. Check the blood glucose immediately before and after surgery and then
hourly until the patient is eating and drinking properly.
5. Give a modified (reduced) dose of subcutaneous insulin at lunch. This
should include some short acting insulin. Continue hourly glucose
monitoring until the first normal insulin dose is given.
6. In the event of a delayed recovery set up an IV glucose/insulin infusion to
control glucose.
7. If the procedure is planned for the afternoon there are two options. In
both cases try to admit the patient before 10:00 am.

Have the normal subcutaneous insulin injected before a light early
breakfast and then cover the fasting period between breakfast and the
minor surgery or procedure with IV 5% glucose to prevent
hypoglycaemia.

An alternative is to omit the breakfast and morning insulin and instead
start an IV glucose/insulin infusion from admission and continue until
the patient can eat and have their normal insulin.
Patients on the afternoon list would normally use their normal evening
meal insulin dose assuming that they can eat as normal at the evening
meal time.
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Guidelines for management of patients with diabetes undergoing surgery
Insulin treated patient undergoing major surgery (having a general
anaesthetic)
1. The patient should have the normal subcutaneous insulin doses on the
day prior to surgery.
2. Put on morning list if possible. On the day of surgery omit the morning
insulin and breakfast if on a morning list. A glucose/insulin should be
started at 08:00 am with hourly glucose monitoring.
3. If the patient cannot be put on the morning list put them first on the
afternoon list. They can have a light early breakfast with a reduced dose
of morning insulin. Admit them before 10am and commence a
glucose/insulin infusion to ensure good glucose control pre-operatively.
4. If the surgery is to be delayed until later in the day or there is a need for
special pre-operative preparation then an alternative is to start the
glucose/insulin infusion straight away instead of morning subcutaneous
insulin.
Insulin treated patient undergoing emergency surgery
1. The patient will need careful assessment.
2. The diabetes management will depend on:

The insulin regimen the patient normally uses taking into account the
duration of action of the insulin used.

The time of the insulin injection.

Degree of glucose control on admission.

Severity of illness and the type of surgery required.

The presence of ketones in the urine (indicates insulin deficiency).
3. Following assessment the options for management include.

To cover a recently injected subcutaneous insulin dose, run a 5%
glucose infusion starting at 100mls/hr.

If there is a delayed recovery or prolonged procedure an IV insulin
infusion will need to be added to the glucose infusion as the previously
injected subcutaneous insulin wears off.

Or set up a glucose/insulin infusion from the start.
July 2008
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Guidelines for management of patients with diabetes undergoing surgery
Intravenous glucose/insulin infusion guidelines
This applies to patients with diabetes who are unable to eat or drink normally.
Aims of treatment

To maintain blood glucose between 4 – 8 mmol/l

Avoid ketonuria (ketones in urine)
The following are suggested guidelines, if in doubt seek further medical
advice.
Infusion regimen

5% glucose at a rate of 100mls/hr (5gm/hr). For patients undergoing
transurethral resection of the prostate i.e. having bladder irrigation use
glucose saline at 100mls/hr (4gm glucose and 3mmol sodium /hr). This is
to reduce the risk of hyponatraemia caused by the bladder irrigation.

Soluble insulin 50 units in 50mls of 0.9% saline run in with a separate
pump.

Only use human Actrapid or Humulin S as the insulin in the infusion i.e.
unmodified soluble insulin. Do not use any delayed action insulin e.g.
isophane or glargine. There is no advantage to using the rapid acting
insulin analogues e.g. lispro or aspart intravenously.

The rate of the insulin infusion is varied depending on the blood glucose
level of the patient.
An example sliding scale
Blood glucose mmol/l
Soluble insulin infusion rate
<4
0.5
4.0 – 8.0
1.0
8.1 – 12.0
2.0
12.1 – 16.0
4.0
>16.0
4.0
see note A
See note B
In the event of hypoglycaemia or excessive hyperglycaemia see the notes
below
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Guidelines for management of patients with diabetes undergoing surgery
Hypoglycaemia

Give a rapid bolus of 200mls 5% glucose.

Increase rate of glucose infusion to 200ml/hr or if only a limited
volume of fluids is allowed use 10% glucose.

Recheck the blood glucose every 10 minutes and ask for urgent
medical advice.

If glucose still <4mmol/l send a venous sample to the laboratory to
confirm hypoglycaemia, give further IV glucose and review the insulin
regimen. If necessary you can give a bolus of 50mls of 50% glucose
via a cannula in a large vein.

It may be appropriate to temporarily stop the insulin infusion. Do not
exceed 30 minutes off an insulin infusion. Monitor blood glucose
and urine for ketones carefully to avoid the serious risk of insulin
deficiency.
A. Excessive Hyperglycaemia

Reduce the rate of the 5% glucose.

Ensure insulin infusion pump is functioning correctly.

Test for ketones in urine.

Ask for medical advice.

Review the insulin infusion regimen.
Guidelines for the monitoring of patients on
glucose/insulin infusions
1. Measure the blood glucose hourly.
2. Check that the infusions of glucose and insulin are running properly using
infusion pumps.
3. Be vigilant for signs or symptoms of hypoglycaemia. These can be
masked in the post-operative patient due to the anaesthesia or analgesia.
If in any doubt measure the blood glucose.
4. Monitor the urine for ketones. Ketonuria is an indicator of insulin
deficiency.
July 2008
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Guidelines for management of patients with diabetes undergoing surgery
5. For patients with Type 1 diabetes the insulin infusion must never be
stopped completely. The patient will be insulin deficient within 30 minutes
of the insulin infusion stopping. If need be, run at the minimum rate of
0.5 units/hr and infuse either 5 or 10% glucose to keep the blood glucose
above 4mmol/l.
6. If other fluids are needed e.g. blood or saline these should be run in
parallel with the glucose/insulin infusion.
7. The serum K+ needs to be monitored closely. Insulin drives K+ from the
extra-cellular space into the intra-cellular space. If necessary supplements
may be needed to be given intravenously.
8. The sliding scale above (page 7) is a starting point to work from. Insulin
sensitive patients may need to have insulin infusion rates reduced e.g.
halved depending on response. Insulin resistant patients, e.g. obese type
2 diabetes on large doses of subcutaneous insulin (>1.5 U/Kg/day) or
catabolic patients, will need insulin infusion rates increased e.g. doubled
depending on response.
9. The glucose/insulin infusion needs to be continued until the patient is able
to eat. When the patient is going to be started on subcutaneous insulin
the infusion should be stopped 30 minutes after the s.c. dose and meal
have been given. The initial subcutaneous insulin regimen should be
unmodified soluble insulin injected before each of the three main meals of
the day and at midnight. Continue this regimen for at least 24 hours
before reverting back to the patient’s normal insulin regimen.
10. Persistent vomiting, post-operative infections or other complications are
possible precipitants for diabetic ketoacidosis and should not be
underestimated.
11. If in any doubt ask for specialist advice.
July 2008
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