Strategies for preventing the endless low roller coaster at night? (Tslim with ControlIQ)

Yesterday was one of those days. They don’t happen often any more but when they do they are a nightmare.
Our son was going low all evening, eating food without boluses. He ate about 75 g of carbs with no rise. Eventually, I fell asleep and he reached 250. I bolused for 22 grams.
And thus began a horrible roller coaster of swinging between 40 and 200 multiple times in the night.
He’s on the Tslim with ControlIQ and I think part of it is that the algorithm is automatically bolusing him the moment he starts rising.
I’m wondering if anyone has any tips for how to prevent this, using Tslim? I tried putting on exercise mode and also shutting off his pump for 30 minutes, but that just delayed the inevitable crash by an hour, max. Solutions that don’t involve waking him up or me having to stay up all night to change a pump setting like basal or ISF or turning off the pump much appreciated. I wish they just had a setting you could institute called “running low” which would turn off automatic basal/bolus adjustments for like 2 hours.

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Hi @TiaG!

Did he have a soccer game? Or a lot of activity?

I think Tandem has different basal profiles you can set, right? Maybe a different profile for those days would help.

The old omnipod (pre-loop) had different profiles. Those were used by many people because there was no looping! Everyone manually bumped their numbers up or down depending on circumstances.

But I think the loop algorithms have made people less aware of basal and IC adjustments. They just let the pump do it all.

If he’s still playing soccer, a different basal profile might help.

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What insulin?
I know that on Novolog I had similar issues.
On Fiasp and Lyumjev, these have been greatly decreased.
I also give a small bolus when eating the larger carb kitchen raids in the middle of the night. Hopefully not enough to give a big drop, but enough to slow the crazy spike from the carbs, which cause the next big drop.

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You can see if Control-IQ gave a correction by going to History / Pump History / Bolus / (select day). Any bolus that was automated will say “Control-IQ Completed.” The basal rate changes won’t be labeled as such, but you can look through them to see if they were elevated too.

If you think that’s a contributing factor, you can turn off Control-IQ. Then turn it back on once he’s stabilized. Turning it off shouldn’t impact CGM readings on the pump, just will turn off the automation (though that also includes turning off suspending basal to prevent lows).

Mostly, I’m so sorry you had one of those nights! I had my first in a looooong time recently… Persistent and stubborn high, then the rage-bolus crash for the next six hours. I ate an astounding amount over the course of the night. :tired_face: Those nights are not fun or restful for anyone involved!

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@TiaG Kaelan is on Loop not Control IQ. But he has the same problem. The way we deal with it is by setting a -80% temporary basal change for 45 minutes to an hour at the same time as he takes carbs at night.

In fact, he just did that 10 minutes ago. In general it works. There are times when it is not long enough but it is rare. It took us a while to find the right amount and duration.

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He didn’t have anything like that. he was diagnosed recently with JIA (juvenile idiopathic arthritis) so he’s been slowly ramping back to soccer. But that day was nothing. He just started having one of those evenings where he could eat carbs and every time we tried to bolus for them he’d go low and it moved into the night.

The issue with the basal profiles we could definitely do. Although thinking about it now, I think just turning off the ControlIQ in this instance might have worked best.

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@michel

Glad to see you again, hope all is well…

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Yes, a blast from the past!

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When bg is unpredictable you may not want to turn off Control IQ. It can slow down and reduce severity of hypoglycemia by turning off insulin entirely when bg is tanking. I find that Control IQ sleep mode is gentler and more nimble because it works by adjusting basal every five minutes rather than dumping a bolus all at once. If bg starts dropping right after the correction you are screwed, with sleep mode on the pump can reverse course. Another way to mitigate the situation is to lower the correction factor in the active profile. You can also leverage the fact that Control IQ will not do a correction bolus until at least one hour has elapsed since the last bolus. So you can give a tiny bolus, like 0.05 units, and buy yourself an hour…

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Control IQ will only deliver correction boluses (Boli?) if the BG is predicted to exceed 180 (10mmol/L). The bolus’ing feature can be disabled by going into sleep mode, which enables only basal corrections.

I finally got a tslim X2 with CIQ a week ago, and personally I find Control IQ to be somewhat lacking. I never would exceed 10mmol/L, and the basal corrections are too slow for my liking.

I’m sticking with manual mode, far tighter control.

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