Disruption of pump-delivered subcutaneous insulin

Patients must be made aware of the possibility of disruption to the supply of insulin from their CSII pump and the consequent action required. Disruption can rapidly lead to hyperglycaemia and ketoacidosis. Possible causes of disruption of pump–delivered subcutaneous insulin are listed in Possible causes of disruption of pump-delivered subcutaneous insulin.

Figure 1. Possible causes of disruption of pump-delivered subcutaneous insulin

If there is disruption to insulin delivery from a continuous subcutaneous insulin infusion (CSII) pump, patients should use their emergency action plan to immediately start alternative subcutaneous insulin injections to manage hyperglycaemia [NB1].

For a CSII pump delivery problem, check for the following causes:

  • air bubbles or kinks in the tubing
  • insecure set connections
  • leakage of insulin on the pump casing or around the injection site
  • infection of the injection site (eg red, sore, swollen)
  • incorrect filling of the cannula after a set change
  • last bolus dose given incorrectly
  • incorrect basal program setting
  • incorrect date and time settings on the pump.

If the problem cannot be identified and/or resolved, contact the pump manufacturer to arrange a replacement pump.

Note:

NB1: Patients should always have a backup supply of prefilled insulin injector pens, a printed record of their current insulin rates and ratios to convert their CSII pump dosage to a multiple daily injection (basal–bolus) insulin regimen, and a 24-hour emergency number to ring for advice on insulin dosage.

If insulin delivery from a CSII pump is interrupted, the patient quickly becomes insulin deficient; they must start using subcutaneous basal and bolus insulin injections immediately and continue until the pump problem is resolved. The long-acting (basal) insulin dose should be at least equal to the 24-hour basal dose delivered by the pump. To calculate the rapid-acting (bolus) insulin doses, the patient should use the insulin-to-carbohydrate ratios and insulin sensitivity factor that are programmed into the pump. See Bolus insulin and carbohydrates.

A patient fact sheet for insulin pump troubleshooting and management (including advice on alternative subcutaneous insulin injection dosage) is available from the Baker Heart and Diabetes Institute website.