Medtronic Pump Software Flaw   (March 25, 2014)

I recently received via snail-mail an "Important Medical Device Safety Information" letter. It's also available on-line.

In the letter, it is stated that "Medtronic has received a small number of reports regarding users who have accidentally programmed the pump to deliver the maximum bolus amount, including one incident that resulted in severe hypoglycemia."

I was surprised to learn that with a series of button-presses on my Medtronic Paradigm insulin pump, I could potentially cause severe hypoglycemia. It's a sequence that I have never gone through (as far as I can recall), but reading the letter, it's easy to see how it could happen, and if I did go through the sequence completely, I'd pop 20 units of insulin -- yee-ouch!

It turns out that the pump has a programming flaw, allowing a sequence of pressing a down-arrow button followed by pressing the activate button will cause the pump to deliver the pre-programmed maximum insulin dose (20 units in my case). Interestingly, this programming flaw only exists in the "Main Menu," and if the user tries the same sequence (pressing a down-arrow button followed by the activate button) in the "Express Bolus" area, the number of units remains at zero rather than jumping to the programmed maximum insulin dose. That's what their letter says, and I can confirm that it's the situation with my pump. (I went through the steps, except the final step of activating the 20-unit
bolus; and as the letter indicates, when I tried this with the "Express Bolus" concept, the dose doesn't jump to 20 but remains at zero.)

The factory-set maximal insulin dose default value is 10.0 units, but I'd guess that most adult users, either on their own, or at the advice of their physician or diabetes educator, have increased the maximal dose to a higher value. And for kids, the default maximal value of 10 units, given as an unexpected bolus, could be life-threatening.

I'm astonished that Medtronic (and presumably the FDA) doesn't consider this a safety issue worthy of a recall. Medtronic admits one "incident." That's one too many, IMHO. It's obvious that the programmers goofed: since the Express Bolus sequence doesn't precipitate the dreaded maximum dose possibility, the Main Menu shouldn't, either. This is a flaw that should be fixed on all affected pumps. Either a software update should be made available somehow, or the affected pumps should be replaced when this flaw is fixed.

Life with a pump is enough of a hassle without worrying about accidentally delivering too much insulin because of a software flaw.