Insulin Prescribing

Question 1

Increased insulin requirements

Answer 1

DKA/ HHS
Sepsis 
Illness
Steroids
Pancreatitis
Dehydration

Question 2

Decreased insulin requirements

Answer 2

Reduced calorific intake
Exercise
Reduced renal function (may reduce drug excretion)
Alcohol

Question 3

What is a variable rate insulin infusion? (sliding scale)

Answer 3

Insulin infusion used for diabetic patients who are NBM eg. Preoperatively

Capillary glucose is checked 1-2 hourly and the rate of insulin infusion is modified according to a predetermined protocol

Continuous IV fluids containing glucose must be given alongside to maintain patient glucose levels and hydration

Question 4

During a variable rate insulin infusion

Answer 4

Continuous IV fluids eg. 5% glucose at 100ml/hour

Check plasma Na and K daily

Re sign the variable rate infusion chart daily

The infusion rate can be modified if the patient is insulin sensitive or resistant

Question 5

Starting a variable rate insulin infusion

Answer 5

Most hospitals have a chart that just needs a signature

Continuous IV fluids also need prescribing

If the patient takes long acting insulin, this should be continued throughout (but short and rapid acting insulin must be suspended)

Question 6

Stopping a variable rate insulin infusion

Answer 6

Confirm patient is eating and drinking and ensure the patient has received their long acting insulin

Give their usual mixed/rapid acting insulin with a meal and wait 30 minutes before stopping the infusion

Monitor capillary glucose QDS for at least 24 hours

Question 7

Insulin prescribing rules

Answer 7

Use insulin prescription chart if available (write insulin as per insulin chart on main chart)

Write units (not U)

Specify brand name and indicate the device the patient uses

Write pre-breakfast, lunch, dinner, rather than times if insulin must be taken before meals

Ensure you corroborate prescription if you are unsure of a dose, never estimate