Care of Diabetic Surgical Patient

Question 1

What is the bodys response to trauma from surgery in terms of glycogenolysis and insulin secretion?

Answer 1

• Increase secretion of stress hormones - cortisol, adrenaline, glucagon
• = glycogenolysis and gluconeogenesis
• Inhibition of insulin release (via adrenaline) and resistance at receptors
• = hyperglycaemia

Question 2

Symptoms/signs of hypoglycaemia

Answer 2

If less <3.3 get autonomic symptoms and signs eg:
* Sweating
* Tachycardia
* Shaking
* Nausea
* Anxiety

If <2.8 get neurological:
* Weakness
* Visual changes
* Confusion
* Dizziness

Severe:
* Coma
* Convulsions

Question 3

GA effect on hypoglycaemia

Answer 3

• Masks symptoms
• Cannot observe mental status changes - occur due to glucose being brains only fuel
• Paralysis can mask convulsions

Question 4

Consequence of hypoglycaemia untreated under GA

Answer 4

• Permanent brain damage

Question 5

Risk of DKA in surgery

Answer 5

• Higher - due to lack of response with insulin
• = hyperglycaemia

Question 6

Aims for CBG during surgery

Answer 6

• 6-12mmol/L (ideally 6-10)
• If <6 - stop VRII and manage or <4 (IF less 2 - emergency)
• Treat hyperglycaemia if >12mmol/L

Question 7

Why are you at increased risk of aspirating gastric contents at anaesthesia induction?

Answer 7

• Loss of protective reflexes eg gag/coughing
• Loss of muscle tone - eg lower OS
• Supine position
• Patient RF - obesity, haitus hernia etc

Question 8

Risks with aspiration of gastric contents

Answer 8

• Aspiration pneumonia
• Chemical pneumonitis
• ARDs

Question 9

Management post op of diabetics - when to seek diabetes team help for hyperglycaemia

Answer 9

• If rises >11mmol/L

Question 10

Half life of metformin and Glicazide vs IV insulin

Answer 10

• Metformin - 6hrs
• Glicazide - 10hrs
• IV insulin - 6 minutes
• takes 4-5 half lifes for drug to be eliminated from the body

Question 11

Indications for VRII in surgery

Answer 11

• Anticipated to have long starvation period (2 or more missed meals)
• Decompensated or poorly controlled diabetes

Question 12

Why are those situations better managed with VRII?

Answer 12

• Limited lasting effects
• Rapid adjustment can be made
• Control hyperglycaemia and hypoglycaemia more effectively

Question 13

Why do guidelines for fluid administration alongside a VRII recommend glucose and K+ added?

Answer 13

• Avoid hypokalaemia - insulin causes K+ to move into cells
• Avoid hypoglycaemia - dextrose gives substrate for VRII to use, steady balance between using glucose and reabsorbing it