Surgery and diabetes
Surgery and diabetes
Dr Abdulhakim Omer Al-Tamimi MD
Assistant prof of surgery
Diabetes mellitus affects 260 million people
There is a rising incidence and prevalence of
About 50% of people with diabetes mellitus
are unaware of their condition.
Approximately 25% of all diabetics
undergoing surgery are undiagnosed on
admission to hospital.
Surgery is a form of physical trauma
It results in catabolism, increased
metabolic rate, increased fat and
protein breakdown, glucose
intolerance and starvation.
In a diabetic patient, the pre existing
metabolic disturbances are
exacerbated by surgery
The type of diabetes, amount of insulin
dose, diet or oral hypoglycaemic agents
must be considered as this will change the
overall management plan
The risk of significant end-organ damage
increases with the duration of diabetes,
although the quality of glucose control is
more important than the absolute time
Because EVERY 24 HOURS there are:
4,100 new cases of diabetes,
810 deaths due to diabetes,
120 kidney failures, and
55 new cases of blindness
Source: NIDDK, National Diabetes Statistics fact sheet. HHS, NIH, 2005.
National Diabetes Education Program
Diabetes: Fasting BS >126 mg/dL, random
Intensive control: BS 80-110
Hypoglycemia: < 60
Diabetes is associated with increased
requirement for surgical procedures and
increased postoperative morbidity and
The stress response to surgery and the
resultant hyperglycemia, osmotic diuresis,
and hypoinsulinemia can lead to
perioperative ketoacidosis or hyperosmolar
Hyperglycemia impairs leukocyte function
and wound healing.
Surgery should be delayed, whenever
feasible, in patients with DKA, so that the
underlying acid-base disorder can be
corrected or, at least, improved
Diabetics have a higher risk of certain
diseases (for example, they are 4 times more
likely to have cardiovascular disease).
Diabetics have a higher perioperative risk.
They are more likely because of their disease
to require surgery and those undergoing
surgery are likely to be less well-controlled
and to have complications from their
Surgeons and anaesthetists operating on
diabetic patients should be familiar with the
risks attached to being diabetic and to the
particular risks of the particular surgery and
of anaesthesia in diabetic patients.
Metabolic response to trauma
Diseases underlying need for surgery
Other drugs e.g. steroids
◦ Secretion of stress
◦ Relative decrease in
◦ Peripheral insulin
◦ Protein breakdown
◦ May develop perioperatively due to the residual effects of
preoperative long acting oral hypoglycaemic agents or
◦ Exacerbated by preoperative fast or insufficient glucose
◦ Counter-regulatory mechanisms may be defective because
of autonomic dysfunction
◦ Can lead to irreversible neurological deficits
◦ Dangerous in anaesthetised or neuropathic patient as the
warning signs may be absent
◦ Give i.v dextrose and monitor glucose levels
◦ Glucagon, cortisol and adrenaline secretion as part of the
neuroendocrine response to trauma, combined with iatrogenic
insulin deficiency or glucose overadministration may result in
◦ Causes osmotic diuresis, making volume status difficult to
determine and risking profound dehydration and organ
hypoperfusion, and increased risk of UTI
◦ osmotic diuresis, delayed wound healing, exacerbation of brain,
spinal cord and renal damage by ischaemia
◦ Results in hyperosmolality with hyperviscocity, thrombogenesis
and cerebral oedema
◦ Frequently measure blood glucose and administer insulin
◦ Any patient who is in a severe catabolic state and has an
insulin deficiency (absolute or relative) can decompensate
◦ Most common in type 1 patients
◦ Increased risk postoperatively, often precipitated by the
stress response, infection, MI, failure to continue insulin
◦ characterised by hyperglycaemia, hyperosmolarity,
dehydration (may lead to shock and hypotension) and
excess ketone body production resulting in an anion gap
◦ restore intravascular volume
◦ eliminate ketonaemia
◦ control blood glucose
◦ replace electrolytes
◦ monitor glucose and ketone levels
Mortality from DKA –5-10%
◦ Anticipate imbalances in potassium, magnesium and
Cardiovascular problems frequently present in long standing
◦ Ischaemic Heart Disease - Often silent ischaemia
◦ Coronary artery disease
Diabetic patients must be considered as being at high risk of
Silent MI in autonomic neuropathy as Cardiac Autonomic
Neuropathy may abolish the hearts response to stress
Induction of anaesthesia and tracheal intubation can lead to a
reduction in cardiac output
◦ Most cardiac and antihypertensive drugs should
be continued throughout the perioperative period
except, aspirin, diuretics and anticoagulants
◦ History to determine effort tolerance, clinical
examination for cardiac failure and an
electrocardiogram in all patients.
◦ Echocardiography can help in assessing an
ejection fraction in borderline cases
◦ Renal dysfunction
Intrinsic renal disease including glomerulosclerosis and renal
papillary necrosis enhance the risk of acute renal failure
Proteinuria is an early manifestation
Dialysis should optimally be done the day before surgery.
◦ Urinary infection
Urea and electrolyte determination.
Dipstix urinalysis for proteinuria
The high risk of large vessel coronary artery
disease in diabetic patients is well
Data from the Framingham study showing a
risk in men and women between 2.4 and 5.1
Diabetes is the most common cause of
myocardial infarction in people under the age
of 30 years.
Peripheral artery disease
is under estimated as it is often
It is present in 25-30% of diabetics
It is an important marker for systemic
(70% of such patients die from coronary heart
disease, 5-10% from stroke).
Diabetic nephropathy develops in close to
40% of patients with type 1 diabetes, and
between 5% and 40% of patients with type 2
occurs in up to 20% of diabetic patients.
Neurological disease is common:
◦ Peripheral neuropathy occurs in 30% of diabetic
◦ Autonomic neuropathy, although less common, is
important as it causes hypotension and may
diminish the autonomic response
to hypoglycaemia (pallor, sweating, tachycardia).
◦ Susceptibility to nerve palsies (mononeuritis) is
Skin disease is more common.
Susceptibility to infection is increased.
Myocardial infarction postoperatively (may be
silent, has a greater mortality).
Stroke. This is consistent with DM and
surgical procedure and other risk factors for
stroke (for example, smoking, anaesthetic
Diabetic foot ulcer
Infections account for 66% of postoperative
complications and nearly one quarter of
perioperative deaths in patients with DM.
Impaired leukocyte function, including altered
chemotaxis and phagocytic activity.
Other infections such as chest and urinary
infections are more common in diabetics.
Tuberculosis can occur particularly in elderly
Poor diabetic control (for example, from the
stress of surgery, lack of oral intake,
postoperative vomiting, etc.).
Poor perioperative diabetic control
Poor intraoperative blood glucose control is
associated with worse outcome after cardiac
surgery in diabetic patients.
Diabetes mellitus is a risk factor for
prolonged intensive care after cardiac surgery
and prolonged length of hospital stay after
A careful preoperative assessment should be
done and may help to improve outcome:
To establish the history of the patient's diabetes and
the state of their diabetic control.
To look for complications of diabetes mellitus.
To establish the safest method of anesthesia and
Assessment of control should be made
(records of HbA1c, FBS , RBS ).
◦ Evidence of angina, intermittent claudication .
◦ Examine for peripheral vascular disease.
◦ Examine for postural hypotension (systolic fall of
>30 mm Hg on standing).
Neurological disease:Symptoms of numbness,
pain, paraesthesia, leg ulcers, transient
Postural hypotension gives a late indication of
An assessment of heart rate variability (HRV)
during deep breathing is a much better way
of detecting autonomic neuropathy .
◦ Symptoms of polyuria may reflect glycosuria or
◦ Anaemia and hypertension should be detected as
possible associated conditions.
Skin, feet and general examination:
◦ The skin should be examined for sepsis.
◦ Pressure areas (heels, buttocks, etc.) should be
examined for sores.
Document the following
◦ Type of diabetes
◦ L ength of time since
◦ Current management
◦ Current glycemic
◦ Presence of
Autonomic neuropathy increase risk of post op gastroparesis
and urinary tract infection
Blood glucose (serial readings) and HbA1c
(more relevant for long-term control). Blood
glucose should be maintained at 4-9 mmol/L
It is very important to avoid hypoglycaemia.
If blood sugar cannot be maintained below 13
mmol/L (234mg/dl), surgery should be
deferred (risk of ketoacidosis or
divided by 18
mg/dl => mmol/l
40 ~ 2.2
45 ~ 2.5
50 ~ 2.8
55 ~ 3.1
60 ~ 3.3
65 ~ 3.6
70 ~ 3.9
75 ~ 4.2
80 ~ 4.4
85 ~ 4.7
90 ~ 5.0
95 ~ 5.3
100 ~ 5.6
110 ~ 6.2
120 ~ 6.7
130 ~ 7.2
140 ~ 7.8
150 ~ 8.3
160 ~ 8.9
mmol/l => mg/dl
2.0 ~ 36
2.5 ~ 45
3.0 ~ 54
3.5 ~ 63
4.0 ~ 72
4.5 ~ 81
5.0 ~ 90
5.5 ~ 99
6.0 ~ 108
6.5 ~ 117
7.0 ~ 126
7.5 ~ 135
8.0 ~ 144
8.5 ~ 153
9.0 ~ 162
9.5 ~ 171
10.0 ~ 180
10.5 ~ 189
11.0 ~ 198
Is a form of hemoglobin that is measured
primarily to identify the average plasma
glucose concentration over prolonged periods
Around three to four months
It is formed in a non
enzymatic glycation pathway by hemoglobin's
exposure to plasma glucose.
Normal levels of glucose produce a normal
amount of glycated hemoglobin.
eAG (estimated average glucose)
ECG (with Valsalva manoeuvre) to assess for
ischaemic and other cardiovascular disease.
Urea and electrolytes (assess for renal
Urine analysis. Ketones (poor control), protein
(possible renal complications) and
bacteriology (for infection).
CXR. This may be indicated to screen for
pulmonary infection, including tuberculosis.
Local or general anaesthesia can be used.
◦ Reduces the stress response
◦ Hypoglycaemia readily detectable with the patient
◦ Postoperative nausea reduced.
◦ Easy postoperative diabetic control.
There are disadvantages of regional blocks
with cardiovascular disease and some
Spinal and epidural anesthesia
It may associated with:
◦ Spinal shock
General anaesthesia: Consideration should
be given to:
◦ The presence of cardiovascular and renal disease.
◦ Prevention of intra-operative hypoglycaemia.
◦ Autonomic neuropathy (It can mask hypoglycaemia
and may exacerbate respiratory depression with
◦ Avoidance of hypotension (increased risk of spinal
◦ Protection of pressure areas.
Type 1 diabetes mellitus
It is usually best to admit patients 2-3 days
before elective surgery, particularly if
outpatient adjustments are difficult.
Ensure good preoperative control usually with
short-acting insulin (or a mixture of shortand intermediate-acting insulin) twice daily.
Monitor blood glucose throughout the day
may be needed every six hours
On the day of surgery starve from midnight
and do not give the first dose of insulin.
Operation should be as early as possible (i.e.
put the diabetic patient first on the list).
Check glucose and electrolytes early on the
day of surgery (defer if glucose >13 mmol/L
or if there is significant electrolyte
Start intravenous (IV) infusions of dextrose
(500 mls 10% dextrose plus 10 units soluble
insulin + 10mmole KCL).
Check blood glucose and electrolytes at the
end of the operation or at 1- to 2-hourly
Monitor blood glucose during surgery at least
every 30 minutes.
Continue this as long as blood glucose is
between 5-10 mmol/L.
Reduce insulin to 5 units if less than 5
mmol/L and increase to 15 units if blood
glucose is 10-20 mmol/L .
After surgery, check glucose every 2 hours
and electrolytes every 6-12 hours, adjusting
infusions as necessary.
Continue infusions but, when eating
normally, restart subcutaneous insulin (as
Preoperatively, control should be assessed.
Patients controlled by diet alone do not
usually need any special measures, providing
control on diet is adequate.
It is better to use short-acting drugs (for
Remember that the hypoglycaemic effect
of sulphonylureas is enhanced by some drugs
(for example, aspirin, sulphonamides,
Metformin should be discontinued 48 hours
prior to and subsequent to surgery in order
to reduce the risk of lactic acidosis.
If control is inadequate, insulin may be
Insulin can be required in the postoperative
On the day of surgery keep 'nil by mouth' as
usual and omit short-acting sulphonylurea.
Monitor blood glucose as for type 1 diabetes
above. If blood glucose is >13 mmol/L, use
insulin to control (small doses of soluble
For major surgery or where there is
prolonged postoperative starvation, use
glucose and insulin infusions as set out
It is preferable to take diabetic patients for
surgery in the morning as first case.
Normally the requirement of insulin is 0.3 U
to metabolize 1gm of glucose.
When FPG < 120 mg ,no insulin is given
except 5% glucose.
When FPG 120- 160 mg ,5 % glucose with 5
units soluble insulin.
For FPG 160- 200 mg , 5 % glucose with 8 U
of soluble insulin.
If FPG crosses 200 and < 250 mg % 5 %
glucose with 10 U of soluble insulin.
Values between 250- 300 mg % to give
normal saline with 6-8 U .
If the blood sugar > 300 mg % 8-10 U are
added to normal saline and surgery is
delayed for few hours till satisfactory
glycemic control is achieved.
All the above infusions are given at the
rate of 100-120 ml / h .
Whatever is the pattern of infusion, the
blood sugar has to be checked every
tow hours and the flow rate is adjusted.
Intra and post operative potassium
monitoring is done and corrected
A few hours after surgery there will be
reduction in the insulin requirement as
the elevated counter hormones due to
surgical stress decline.
Blood sugar may rapidly fall after surgical
drainage of an infected area.
Type 2 diabetes can be safely switched
over to oral drugs after a week.
In coronary artery bypass surgery and
during and after renal transplantation the
insulin requirements will be exceptionally
In general, emergency or non-elective cases
must have blood glucose controlled with
insulin, glucose and potassium infusions as
above with special attention being given to
rehydration before surgery.
Diabetes is the silent killer as it affects almost
all the organs of the body and usually leads
to a host of complications if not controlled
Hypertension, edema, proteinuria and renal
Urinary microalbumin excretion testing
Spot urine sample testing
Tight control of blood glucose in most
Dietary protein restrictions.
Excessive urinary microalbumin excretion
should be treated with an ACE-inhibitor
agent (provided there are no
contraindications) even if their blood
pressure is not elevated. This helps to
control intraglomerular hypertension.
High blood pressure should be aggressively
treated in diabetic patients and target blood
pressure should be less than 130/85mg Hg.
Due to compromised host defense and
high blood sugars, microbes with low
virulence easily cause infections of the
Staphylococcus aurous infection
causing boils, carbuncles and
abscesses are the most common skin
Hand abscess with necrotizing fascitis
Upper eyelid abscess
Tuberculosis is common with diabetes
Sputum and urine examination
In diet treated diabetics, return to preoperative dietary management incase of
The diabetic patient with autonomic
dysfunction who has abdominal surgery can
develop significantly lower core body
temperature than the non-diabetic patient.
This diabetic patient usually has impaired
vasoconstriction, which predisposes one to
Hypothermia is associated with poor wound
healing and can precipitate a hyperglycemic
Laparoscopy versus open procedures
Role of nutrition