I got my first “Insulin Flow Blocked” error message since using the Medtronic 780G Insulin Pump. (See Why I love this pump for my previous writing on this pump.) This error has happened occasionally with my former insulin pump too (the 670G model). In my experience, the infusion set is often the cause of this error. It typically happens on the same day I changed my infusion set, and sometimes the cannula is visibly bent. 

When starting a new infusion set, there’s always a chance of an issue. The infusion set is where the pump connects to your body, and this connection has inherent variability. The cannula may bend, hit scar tissue, or be sore, or the site may not absorb well.

It’s also possible for the blockage to be in the tubing. I had that happen once.

Because of the chance of an infusion set problem, I always carry an extra infusion set with me. I also typically leave my old infusion set in, so I can switch back to it, assuming it was working fine.

The insulin flow blocked error happened at mealtime. It was very inconvenient timing. I had just bolussed but didn’t know if my body got the entire bolus because of this error.

Fortunately, I was able to solve the problem easily. The pump prompted me to “rewind reservoir” or “resume basal”. I swapped back to my old infusion set, selected “resume basal”, and the pump remained in Smartguard (auto mode)!! (If I recall correctly, this is new behavior compared to the 670G, which would kick you out of Smartguard mode with this error.)

Knowing that at least some of the bolus didn’t get delivered, I did another partial bolus for the meal. I went high after the meal, and the pump fixed the issue with its auto-corrections. You can see the auto corrections (purple verticle lines on top) on the graph below.

It took a while for my blood glucose to get back in range, but I didn’t have to do any manual intervention, aside from swapping out the infusion set.

If you get frequent insulin flow blocked errors, you should discuss it with your healthcare team because there may be a solution, like using a different kind of infusion set or a different body location. In this instance, I was using the Mio Infusion Set, which I have a supply of that I’m trying to use up. I have also used the Mio Advanced and the 7-Day Extended Infusion Set and have yet to experience this issue. I don’t know if that means I won’t or I just haven’t yet. Those sets do seem to have improved insertion, although there’s still the body variability, so there’s always a chance of an infusion set problem.