Problems of diabetic patients and implications in anaesthesia

1. Anaesthesia in
the Diabetic
patient
Dr Kapila Hettiarachchi
Consultant Anaesthetist
SBSCH- Peradeniya
shaankh@icloud.com

2. Part 1 A questions related to DM
(10th November 1992)
A 40-year-old diabetic of 10 years duration presents for routine abdominal surgery.
How would you evaluate his fitness for anesthesia? Outline the problems that
could occur during the intra-operative period.
(Dec 2005) 5.
A 70 year old female with a history of diabetes mellitus of 15 years duration presents with a peri anal abscess.
Describe your anaesthetic management.
(Nov 2007) 8.
A 50 years old male with a long standing history of diabetes mellitus presents for a wound toilet in the left leg.
Outline your perioperative management of this patient.
(April 2011) 6.
A 45 year old lady with Type 1 diabetes mellitus controlled with insulin requires total abdominal hystetectomy. Describe your
anaesthetic management
1st April, 2003
A 52 year old diabetic patient who is on short acting oral hypoglycaemic drugs is
presenting for abdominal hysterectomy.
Describe the perioperative management.

3. Type of DM
Medication
End-organ changes
Nature of surgery
Urgency of surgery
Level of glycemic control

4. To Assess History and
Examination
Investigation
Nephropathy • H/o hypertension,
swelling of face and
body
• Hypertension and its
medication
• Urine – Proteins Sugar
• Microalbuminuria on a
timed overnight
collection.
• B. Urea, S. Creatinine,
S. Electrolytes
irrespective of age.
• Possible need for suxamethonium as a result of gastroparesis.
• Ensure adequate hydration to reduce postoperative renal
dysfunction.

5. To Assess History and
Examination
Investigation
IHD
CHF and
Cardiomyopathy
• Angina or MI
• Breathlessness, swelling
of feet
• Poor exercise tolerance
• Oedema feet, enlarged
liver, raised JVP, basal
crepts, S3/S4
• ECG
• X-ray Chest

6. To Assess History and
Examination
Investigation
Autonomic
neuropathy
• Early satiety, lack of
sweating
• Gastroparesis in the
form of vomiting,
nocturnal diarrhea,
abdominal distension.
• Orthostatic hypotension
• Bladder atony and
urinary retention
• Impotence
• Palpitation
• Sensory discomfort of
lower limbs
• Resting tachycardia
• Irregular pulse
• Dense peripheral
neuropathy.
• SBP response to
standing: BP(lying) -
BP(Standing) (>30 mm
Hg)
(Normal is <10 mmHg)
• DBP response to
sustained handgrip:
Handgrip sustained at
30% of maximum
squeeze for upto 5
minute & BP every
minute.
• Difference between DBP
just before release –
Initial DBP.
(Normal is > 16 mmHg)

7. To Assess History and
Examination
Investigation
Autonomic
neuropathy
• Valsalva: Ratio of the Longest R-R to
the shortest R-R
(Normal is > 1.21)
• Beat-to-beat variation with deep
breathing obtunded: Mean of
(maximum HR – minimum HR) of 3
cycles of 6bpm (< 5bpm)
(Normal is > 15 bpm)
• HR response to standing obtunded:
Ratio of Longest R-R around 30th beat
after standing to the Shortest R-R
around 15th beat after standing
(Normal is > 1.04)
Autonomic neuropathy predisposes to hypothermia under anaesthesia

8. To Assess History and
Examination
Investigation
Retinopathy Vision deterioration Ophthalmologic examination
• Prevent surges in blood pressure, for example at induction, as this
might cause rupture of the new retinal vessels.

9. To Assess History and Examination Investigation
Stiff joint
syndrome
• Stiffness in hand joints
• Inability to approximate the
palmar surfaces of phalangeal
joints.
• “Prayer Sign”
• Non-familial short stature
• Tight-waxy skin
• X-ray cervical
spine to
delineate limited
atlantoaxial
extension.
Difficult intubation

10. To Assess History and
Examination
Investigation
Electrolyte &
metabolic
derangement
- Non-Compliance of drug
- Severe infection or
starvation
- Poor control in the past
few days/weeks
- S/S of hypoglycemia or
ketoacidosis
- ABG and
electrolytes

11. To Assess History and Examination Investigation
Standard of BS
Control
- Hyper/Hypoglycemic episodes
- Medication and Compliance
• BS (fasting, PP)
• GTT (if required)
• Glycosylated Hb
(HbA1c)

12. Regional blocks
 Regional techniques offer some potential Advantages
1. Avoidance of intubation
2. Having an awake patient to warn of impending
hypoglycaemia
3. Earlier return to normal eating patterns.

13. Disadvantages
1. Risks of nerve injury higher. Poor patient positioning is
more likely to result in pressure sores that are often slow
to heal given poor peripheral blood flow.
2. Combination of LA with epinephrine may pose
greater risk of ischemic or edematous nerve injury
(or both) in diabetic
3. Document peripheral neuropathy
 keeps the patients and relatives informed
 avoids medico-legal hassles later on
 Autonomic neuropathy can result in sudden
tachycardia, bradycardia, postural hypotension and
profound hypotension after central neuraxial blockade.
4. The chances of epidural abscess are also increased.

14. Airway
 Anticipate difficulty in intubation.
 Rapid sequence induction

15. Respiratory
 Obese
 Infection
 Diabetics are prone to all types of infection.
Indeed an infection might actually worsen diabetic
control.
 Tight glycaemic control will reduce the incidence
and severity of infections and is routine practice in
the management of sepsis and diabetic foot
infections.
 Perform all invasive procedures with full asepsis.

16. Anaesthetic Management
General Principles
 Avoid hypoglycaemia (under 4mmol/l) as this can cause irreversible
cerebral damage
 Avoid severe hyperglycaemia (over 14mmol/l) to minimise
dehydration and metabolic upset
 Type 1 diabetics need insulin to prevent ketogenesis and “metabolic
derangement’’
 Aim for a blood glucose between 6 and 10mmol/l
 Accurate, easy-to-use glucose monitors, make the practice of
“permissive hyperglycaemia” unacceptable given the known outcome
benefits of tight control

17. Anaesthetic Management
General Principles
 First on the operating list to shorten the preoperative fast and
potentially allow normal oral intake later that same day
 Tight metabolic control is important for both type 1 and type 2
patients. If control has been tight in the preceding weeks then fluid
and electrolyte balance will be essentially normal.
 The best marker for recent control is the percentage of
glycosylated haemoglobin (HbA1C).
7% indicate good control
over 9% and particularly
12%, indicate poor control likely associated electrolyte and water
loss.
 Microvascular complications are more

18. Anaesthetic Management
 Assess control by blood glucose.
 Continue all diabetic medication until the day of surgery except:
a.) Chlorpropamide (stop 3 days prior as long acting, substitute with a
shorter acting sulphonylurea)
b.) Metformin only if major surgery as risk of lactic acidosis
c.) Glitazones
d.) Long acting insulin – substitute with short/intermediate
acting
 Measure blood sugar preoperatively – 4 hourly if on insulin, 8
hourly if not
 Major or minor - eat within 4 hours of the operation then treat
this group as having “Minor” surgery. Otherwise, surgery is
“Major”

19. Pre-medication
 Prescribe an H2 antagonist such as
ranitidine150mg and
 metoclopramide 10mg, at least 2 hours
preoperatively

20. Drugs
 Induction agents- If autonomic neuropathy present use
more cardiac stable drugs.
N.B. Propofol might drop BP drastically
 Analgesics- high doses will obtund stress
 Muscle relaxants - careful about suxamethonium if
renal failure is present
 Inhalationals - halothane and sevoflurane, produce
greater negative inotropic effects in diabetic patients
than in non-diabetic patients

21. Minor surgery, type 2 diabetes NOT on
insulin (diet/ tablet controlled), 1st on list
 Preoperative blood sugar <10mmol/l Take normal
medication including evening dose
 Preoperative blood sugar >10mmol/l Treat as if
“Major” surgery
 Omit oral hypoglycaemic on morning of surgery
 Monitor blood glucose 1 hour preop; intraoperatively
if over 1 hour; and 4hourly postop until eating.
 Recommence oral hypoglycaemics with first meal

22. Minor surgery, type 2 diabetes ON
insulin/type 1 diabetes, 1st on list
 Take normal medication on day prior*
 Omit morning SC insulin if glucose < 7 mmol/l
 Give half normal insulin if glucose >7 mmol/l
 Monitor blood glucose 1 hour preop; intraoperatively at
least once; 2 hourly until eating and then 4 hourly.
 Recommence normal SC insulin with first meal
*If taking a long acting insulin, either convert to
short/intermediate acting several days prior or ½ the dose
the day prior to surgery

23. Major surgery, all types of diabetes,
1st on list, infusion pump available:
 Normal medication on day prior (unless very poorly controlled, in which case,
establish sliding scale 3 days prior)
 Day of surgery, omit oral hypoglycaemics/ normal SC insulin
 Check blood glucose 1 hour preop; hourly intraop until 4 hours postop; 2 hrly
thereafter and 4 hourly once stabilised.
 Insulin is the key infusion. With close monitoring, and adjustment according to a
sliding scale, there is no absolute requirement for concurrent dextrose containing
solutions, as the tendency will be purely towards hyperglycaemia.
 However, commonly 5% or 10% dextrose solutions containing 20mmol/l of KCl are
infused at a steady rate of 100ml/hr to provide carbohydrate substrate. Titrate the
insulin infusion (through a dedicated line with one-way valve) as below.

24. Blood glucose
(mmol/l)
Insulin infusion
rate (unit/h)
If poor control*
(unit/h) *If glucose not
maintained <10mmol/l then
increase the rates
<4 0 0
4.1-9 1 2
9.1-13 2 3
13.1-17 3 4
17.1-28 4 6
>28 6 (check infusion running) 8

25. Postoperatively
 Check BS
 Minor Surgery: Restart OHD with first meal
 Major surgery: Treat as IDDM
When oral diet is resumed, t.d.s soluble insulin 8-12
units before each meal,
restart oral therapy when daily requirement is less than
20 units.

26. Major surgery,
all types of diabetes,1st on list,
NO infusion pump available:
 Preoperative management, blood glucose testing and
postoperative management as previous example.
 Start intravenous infusion of 500ml 5% or 10%
dextrose solution with insulin and KCL added as
below according to blood glucose and potassium
measurements

27. Blood
glucose
(mmol/l)
Soluble
insulin
(units per
bag)
• Blood
potassiu
m
• (mmol/l)
Potassium
Chloride
(KCL)
(mmol per
bag)
<4 0
4-6 5 <3 20
6-10 10 3-5 10
10-20 15 >5 0
>20 20
*If blood potassium level unavailable, add
10mmol KCL per bag