Anesthesia for patient with comorbidities

Question 1

What is diabetes?

Answer 1

An endocrine disorder associated with insulin deficiency and/ or resistance which results in poor glycemic control

Question 2

Signs and symptoms of diabetes?

Answer 2

Polyuria, Polydipsia, Polyphagia, glycosuria, hyperglycemia

Question 3

Types of diabetes?

Answer 3

Type 1 (Insulin dependent DM - IDDM)
Type 2 (Non-insulin dependent DM - NIDDM)

Question 4

Effects of DM on the CVS system?

Answer 4

Hypertension
Ischemic heart disease.
Myocardial infarction
Cerebrovascular accidents
Cardiomyopathy

Question 5

Effects of DM on the nervous system?

Answer 5

1. Increased risk of stroke
2. Autonomic and peripheral neuropathy.

Question 6

Effects of DM on the resp. system?

Answer 6

Increases the risk of perioperative chest infections

Question 7

Effects of DM on the GIT?

Answer 7

Gastroparesis-reflux

Question 8

Effects of DM on the renal system?

Answer 8

Increased risk of renal failure

Question 9

Effects of DM on the MSK system?

Answer 9

Stiffening of ligaments around joints leading to limited joint mobility
Also causes proteolysis which affects wound healing

Question 10

Preop assessment of a DM patient?

Answer 10

1. History
2. Exam
3. Investigations: routine vs special
4. Routine: FBC, Special: FBS, HBA1C, U and Es, Cr, ECG, Urine protein

Question 11

General Management principles of DM?

Answer 11

1. Avoid hypoglycaemia
2. Avoid severe hyperglycaemia
   - Aim for a blood glucose between 6 and 10mmol/l
3. Diabetic patients should be placed first on the operating list
4. Tight metabolic control is important for both type 1 and type 2 patients.
   - Measure blood sugar preoperatively: 4 hourly if on insulin, 8 hourly if not
5. If the patient is expected to eat within 4 hours of the operation then treat this group as having “Minor” surgery. Otherwise, surgery is “Major”

Question 12

Plan of anaesthesia?

Answer 12

1. Regional vs GA
2. Depend on site of procedure, coexisting disease and extent of surgery

Question 13

Plan for well controlled diabetic/minor surgery/normal FBS in non insulin dependent diabetics?

Answer 13

1. First on the list
2. Omit oral hypoglycemics
3. Blood sugar monitoring:
   - 1 hr pre-op
   - at least once intra-op or every hour if procedure extends more than an hour
   - Post op 2 hourly until eating, then 8 hrly

Question 14

Plan for well controlled diabetic/minor surgery/normal FBS in insulin dependent diabetics?

Answer 14

1. First on the list
2. Omit normal sc insulin if glucose<7mmol/l
3. Give half normal insulin if glucose > 7mmol/l
4. Blood sugar monitoring:
   - 1 hr preop
   - atleast once intraop
   - Post op 2 hourly until eating, then 4 hrly
5. Restart normal sc insulin with first meal

Question 15

Plan for major surgery in diabetic patients?

Answer 15

1. Check blood sugar and potassium pre-op
2. Omit oral hypoglycemics or normal sc insulin
3. IVF: 5% dextrose, 500ml/4hrly OR 10% dextrose 500ml/8hrly
4. Start iv insulin sliding scale
5. Blood glucose measurement:
   - 2 hourly from start of infusion
   - hourly intraop
   - Hourly post op until 4 hrs then 2 hrly
   Note: Plan includes patients for minor surgery whose admission blood glucose is > 7mmol/dl

Question 16

Sliding scale for major surgery in diabetic patients?

Question 17

Major surgery post op in NIDDM?

Answer 17

Stop infusion and start oral hypoglycemics when eating and drinking

Question 18

Major surgery post op in IDDM?

Answer 18

1. Stop infusion when eating and drinking
2. Start on soluble insulin initially
3. Calculate total daily dose the patient was taking preoperatively
   - Administer the daily dose as sc soluble insulin divided into 3-4 daily doses
4. Adjust doses until blood sugar levels are stable
5. Restart normal regimen when the sugar levels are stable