Insulin pump therapy opens the door to ketoacidosis in the event of a problem with the insulin delivery. With no intermediate or long-acting insulin in the body, we rely on the pump’s delivery of basal insulin in the form of tiny pulses of rapid-acting insulin. Any interruption in insulin delivery can result in a sharp rise in blood sugar and ketone production starting as soon as three hours after the last bit of insulin was infused.
This can be caused by
- Tubing or infusion set clogs
- Leaks where the cartridge connects to the tubing
- Air pockets in the tubing
- “Tunneling” or “seepage” of insulin when bolusing
- Dislodgment of the cannula from beneath the skin
- Improper or insufficient priming
- Extended pump suspension or disconnection
- Insulin spoilage due to heat or excessive agitation
- Accidental erasure of basal settings
- Malabsorption of insulin at the infusion site
When the body receives no insulin for several hours or more, harmful acids called ketones start to be produced. The combination of high blood sugar, dehydration and ketones can lead to a life-threatening condition called ketoacidosis, or DKA.
The first and most important step in preventing DKA when using an insulin pump is early detection of a problem. This is accomplished by checking for ketones with any unusually high blood sugar levels – preferably on a meter that measures ketones from a fingerstick blood sample. The absence of ketones would indicate that the high reading is probably due to insufficient insulin coverage for food eaten recently. The presence of ketones indicates either an illness/infection or, more likely, a problem with the pump’s insulin delivery.
When ketones are present
- Give an injection of insulin using a syringe (using normal correction formula). To ensure that the insulin reaches the bloodstream as quickly as possible.
- Drink as much water as possible.
- Change out your pump’s cartridge, tubing and infusion set using a fresh vial of insulin.
Failure to correct the problem could result in ketoacidosis in just a few hours!
Preventing Insulin Delivery Problems
- Prior to disconnecting at your infusion site for less than an hour, bolus an amount equal to the basal that you will miss.
- Limit your disconnection and “suspension” periods to no more than an hour at a time. If you must disconnect for more than an hour, re-connect hourly and bolus an amount equal to the basal insulin that you will miss for the upcoming hour.
- Check your infusion site and tubing at least once daily. If the infusion set tape is peeling loose or if you spot any redness/swelling around the infusion site or blood in the tubing, move & replace the infusion set immediately. If you have a “lump” under the skin that does not resolve in 48 hours, contact your physician.
- If you spot air pockets in the tubing, disconnect and prime until the air has been purged completely out.
- Rotate infusion sites so as not to repeat the same area too frequently.
- If you smell insulin or detect moisture around any of the tubing joints or at the infusion site, replace the set & tubing immediately.
- If insulin tends to seep out at the site when you bolus, prolong the bolus delivery time or switch to a longer cannula.
Responding to Alerts
- If your pump alerts you of a tubing/infusion set clog (“no delivery”, “occlusion”, “blockage detected”), replace your cartridge, tubing and infusion set immediately.
- Change your cartridge as soon as possible after you receive your “low cartridge” warning. This minimizes the risk that your cartridge will run out completely.
- Lubricate your reservoir well by rotating the barrel and pushing up & down several times prior to filling with insulin.
- Make sure there are no significant air bubbles in the cartridge before priming the tubing.
- When priming the tubing, point the cartridge up and hold the end of the tube above the level of the pump.
- When exposing your pump to very warm weather, keep it out of direct sunlight and place it (and the tubing) in a cooling pack such as a “Frio”.
- Change the insulin cartridge and tubing more frequently when exposing the pump to heat.
- Keep the pump and tubing out of whirlpools, hot tubs and saunas.
(for taking a “pump vacation” or due to a pump malfunction)
Basal insulin: Take an injection of long-acting insulin immediately upon going “off” the pump.
Mealtime insulin: Use pens or syringes to take appropriate doses of rapid acting insulin at each meal/snack (and for elevated BGs).
Reconnection to pump: Put your settings into your new pump, and wait until your long-acting insulin is nearly finished working before reconnecting to the pump.
*Keep a written record of your current pump settings, just in case of a pump malfunction
©Gary Scheiner MS, CDCES – Integrated Diabetes Services. May be reproduced and used for patient education, but not sold.