Variable rate insulin infusions

Diabetes & endocrinology
NHS Lothian

 

  • A variable rate insulin infusion (VRII) is a short acting insulin (actrapid) given as a continuous IV infusion
  • IV actrapid has a short half life, so avoid interruptions to reduce the risk of hyperglycaemia and ketosis
  • Continue long acting insulin alongside the VRII at 80% of the patient's usual dose. Withold mixed and short acting insulin while on a VRII
  • See intravenous insulin prescribing chart.

Who?

  • Type 1 or pancreatic diabetes and:
    • vomiting
    • fasting and will miss >1 meal
    • little or no oral intake
  • Patients with any type of diabetes who are significantly unwell with co-existing hyperglycaemia
  • Don't use in HHS or DKA - see separate protocols

 

Fluids?

Always prescribe with a glucose containing fluid.

  • First line
    • 0.18% saline / 4% dextrose / 20mmol KCL at 100ml/hr
  • Second line (if saline difficult/ needing to run other saline including fluid/ relatively hypoglycaemic)
    • 5% or 10% dextrose 100ml/hour
    • Include KCL unless hyperkalaemic

 

Fluid overload?

  • Discuss with senior - do they definitely need a VRII?
  • If yes - 10% dextrose at 50ml/hr or 20% dextrose at 25ml/hr
  • Include KCL unless hyperkalaemic

 

Stopping?

Stop when eating and drinking normally.

  • If on once daily long acting insulin:
    • Ensure has had usual long acting insulin in the 24hrs prior to stopping. Can stop at any time.
  • If on a twice daily mixed insulin:
    • Restart normal insulin at a meal time
    • Discontinue the VRII 30 mins after this.
  • If on a basal bolus regime:
    • The long acting insulin should have been continued during the VRII, if it hasn’t a dose MUST be given before the VRII is stopped
    • o Restart normal meal time short-acting insulin and stop VRII 30 mins after this has been given.

If unclear treatment or not on insulin prior to VRII; or high insulin requirements on VRII; discuss with diabetes team before stopping.