Last night I inadvertently had my pump deliver 20 units of insulin. During the following 6 hours I was able to maintain my glucose levels between 220 and 100, by consuming 50 glucose tablets, having honey, sorbet and orange juice.
It was not fun but thanks to my family’s support everything went well.
I had glucagon available and we were ready to go to the hospital if necessary.
Why did I overdose? I am using the Tandem T-slim pump. The loading procedure is long and requires a lot of focus in what you are doing it.
I was loading a new cartridge and a combination of two mistakes allowed my pump to deliver the full maximum tubing delivery amount of 30 units into my abdomen.
First mistake was automatically answering ‘Yes’ to the question 'Are you disconnected?", without actually disconnecting the tube from my body. . I know I should not insert the canula before I finish filling the tube and see the drops. But I had inserted it and did not disconnect.
Second mistake was to forget to stop the Fill Tubing step, so that the pump delivered the full 30 units of insulin into my body.
I am usually very focused when I change a cartridge, but apparently my mind wandered a couple of times and only realized what I had done when the alarm for maximum delivery sounded.
Cannot explain why or how the two mistakes happened. I have been on a Medtronic pump for 5 years and on the Tandem pump for for a year and in general I am happy with the Control-IQ feature.
I think that adding some extra safety features in the pump could have prevented this episode.
- Do not make the fill tubing step deliver insulin automatically, ask to press a button continuously instead.
- Set an alarm once the minimum 10.5 units has been reached and ask if more insulin is needed.
- Set an alarm at 15 units and ask if you want to continue.
I know what the correct procedure is and I am aware of the mistakes I made.
My posting here is aimed to alert other people about this event. I just want to share it with other diabetics.
I am going to contact Tandem to let them know about my experience and suggestions.
Thanks for your support reading this.