Insulin like water?

Wondering how you troubleshoot when insulin just does not seem to be doing anything. My son is not sick and is in good spirits, but the insulin doesn’t seem to be even bending the curve at all today. His breakfast was low on carbs as was his lunch, but he’s spiking into the 300s and the weird part is that it’s just this steady rise by +7 for more than 2 hours. I’m wondering if that’s a sign of a bad insertion site?

And if I decide it’s a bad site and want to do a manual injection to correct him, do I just assume all the insulin I pumped into his body is no longer on board? Or do I subtract what is ostensibly on board based on the pump calculation?

If it were me, I’d correct with a shot (taking into account the IOB, and I also bolus the same amoutn with the pump’s infusion set disconnected so that I can track the injected IOB), and if still high in two hours change out the infusion set AND insulin. There’s no real way of knowing exactly what it might be, but when I go really high for no reason< I’ve just started automatically assuming my infusion set or insulin is bad, since it usually is. That’s one of the downsides of pumping.

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Thanks Jen. How often do you find a site goes bad? My son is an active toddler who’s in the throes of potty training so I’m imagining he does more to disrupt his sites than others, but still, it would be helpful to know if this is something we can expect once every few weeks, once a month, etc…

And it IS possible for insulin to go bad, though it’s not an everyday occurrence. The quickest way to prove it (or eliminate it as a possibility) is to try another vial, preferably via a shot.

For me it seems to happen somewhat often, but thatès partly because my immune system is cranky and likes to reject sites and make them so irritated that they stop working. (I had to switch to metal sets because it was happening at least once a week or more with the plastic ones, and even with the metal ones, which supposedly are reliable methods of insulin delivery, it manages to happen a few times a year.)

When I get in a situation like this, I’m high and going up etc. and I know insulin was cut off for some reason for sure, like the inset top fell off once, kinked inset, pump shut off etc. I do an injection right away, bolus the insulin on the pump with the tube disconnected so I have it recorded in iob, change the inset, maybe change out the cartridge if I’m worried the insulin is bad. I don’t worry about iob then usually but I would try to calculate that in if he has a lot on board.

If you don’t think it is a pump/inset issue, you can try an increased basal rate too and see if this helps. Sometimes if you’re sick or you just need more for some reason, that can help too.

As an adult T1 I’m hesitant to advise on a problem with a toddler because there are so many things that are metabolically specific to little kids–body size, energy level, growth hormones, god-knows-what. But for anyone on a pump these kinds of mystery highs do tend to suggest a delivery issue. I assume you’ve checked to see if there’s any obvious sign of swelling or bleeding at the infusion site? Bubbles in the feed line can also be an issue if it’s not a tubeless system. Nasty thing about that is that the pump “thinks” it’s delivering even though there’s a significant gap in the flow. You can check for voids by holding the tube up against a backlight. If you see gaps you can do a temp basal at a higher level for an hour or so. If not, if you have injectable insulin you can try administering a correction dose and monitor the effect. If it works then there’s something wrong with the current infusion path and replacing the set would be in order.

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If I have elevated BGs, sustained 250+, 2+ hours after a pump bolus but with a suspected failed site, I will often take a repeat syringe bolus and closely watch with appropriate fingerstick followup. That being said, like @DrBB acknowledges, a toddler has other significant variables like growth hormones that do not affect me. I would try to replace all or most of the insulin suspected to be missed from a failed infusion site. You can also develop quite a missed basal backlog when a site goes bad.

Usually for bubbles I disconnect the pump and primte them out of the tubing.

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If this happens to me and I call the pharmacy mail or otherwise and tell them sold dead insulin, I have always been able to get replacements. Few questions asked.

Thanks everyone for all the insights! The site definitely played a role; there was a ton of blood and it’s now bruised and swollen. He must have injured it somehow during rough and tumble play at daycare, as it looked totally fine in the morning. I gave him half of the IOB by needle, changed the site, then gave him the remaining IOB using the new pump site when I saw he was plateaued and not dropping like I’d wish after the needle stick. He did need some fast-acting carbs to prevent a low, but not much, so likely some of the initial insulin made it into him.
Next time I think I’ll suspect a bad site sooner and just default to a site change and needle correction with fast-acting carbs on hand in case he crashes. No point in him being in the 300s for an hour or two.