Tandem tslim - Control IQ - Sleep Mode

dtennant9

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Hello,

I have been having a few issues recently with Control IQ(with Dexcom G6) overnight when it is in sleep mode, and I was wondering if anyone else had ever had a similar experience and how you had got around them.

I am getting low alarms every night, usually around 4-5am but sometimes at other times.

My highest basal setting of the day is from midnight to 3am, so logically this is where I would pinpoint that my lows later in the night are coming from and would reduce this. However, when I start digging a littler deeper in to the pump history, it seems that Control IQ is actually bumping this basal up even further due to how aggressive the sleep mode is.

My basal at this time is 1.2 units/hr, however the pump is constantly changing this often up to 3 units/hr.

My correction factor is also ridiculous overnight at 1u:25mmol to try and stop it from putting my background up so much.

I‘m totally at a loss as to what I need to change. I contacted my clinic, they suggested reducing my basal as I was going low. They weren’t quite grasping that the pump was already putting my current basal up. Nobody in the clinic seems to be that knowledgeable on the Tandem with Control IQ. Just about every time I call, they also tell me to increase my target, however I have to point out that this is not possible with Control IQ switched on.

Perhaps I need to actually increase this basal rate so that the pump does not?

I would be interested to hear if anyone else has had this experience, and how you went about solving it.

I am wondering about not having sleep schedule on overnight for the time being till I sort out the optimum basal patterns, then aim to start getting my levels steady at bedtime and overnight at the rate the pump is trying to aim for.

I had also read about people having Compression Hypos overnight on the Dexcom G6, however I wasn’t sure how true this could be. I am the first to admit that I am not great at checking the overnight low alarms with a finger prick as I just want to sleep

In my 12 years as a Type 1 I have never felt so lost, when Control IQ was meant to help things.

Thank you for reading.
 

searley

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You could just not put it in sleep mode
 

Hopeful34

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I know it can be a pain checking your blood sugar with a finger prick test @dtennant9 , but it's really important to establish if you are low or not.

Personally I'd switch off control IQ and do some fasting basal rate tests, to see if you need to change any of your settings. Then check carb to insulin ratios, and correction ratios as well. Once these are right, then i'd try control IQ and sleep mode again and see what happens.

It takes time to get the settings right on a new pump, and can feel overwhelming, but you'll get there. Try not to stress, but I know that's easier said than done. Take care.
 

EllieM

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My (very) limited understanding of sleep mode is that it has a very slightly lower target bg but also turns off auto bolus corrections while you sleep. So though it will adjust your basal rates slightly it won't do any hourly bolus corrections if you are running too high.

Can I ask what level you are starting your night at? (For me, I find the night time mode keeps me at roughly whatever my sleep mode starts at, so my issue is too high readings if I start too high.

I'm afraid I think you do need to check those overnight lows though. Any chance you could move your sensor to somewhere where you won't sleep on it overnight?
 

searley

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My (very) limited understanding of sleep mode is that it has a very slightly lower target bg but also turns off auto bolus corrections while you sleep. So though it will adjust your basal rates slightly it won't do any hourly bolus corrections if you are running too high.

Can I ask what level you are starting your night at? (For me, I find the night time mode keeps me at roughly whatever my sleep mode starts at, so my issue is too high readings if I start too high.

I'm afraid I think you do need to check those overnight lows though. Any chance you could move your sensor to somewhere where you won't sleep on it overnight?

It can increase basal rate significantly, infact you will get more insulin by basal increase than that of bolus corrections

Sleep mode has much tighter control which is why many use it all the time
 

Juicyj

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Are you sure these are lows and not sensor compression lows ? I get the odd compression low during the night, if my alarm buzzes and I know I am sleeping on my sensor arm I turn over and BG reading will sort itself out if I know I am going low then I reach for the glucose, best to check any night time low against a meter to verify this though.

Personally I have no issues with sleep mode on the T Slim - I can go to sleep high, T Slim and Control IQ works it out during the night and I always wake in range.
 

Chas C

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Are you sure these are lows and not sensor compression lows ? I get the odd compression low during the night, if my alarm buzzes and I know I am sleeping on my sensor arm I turn over and BG reading will sort itself out if I know I am going low then I reach for the glucose, best to check any night time low against a meter to verify this though.

Personally I have no issues with sleep mode on the T Slim - I can go to sleep high, T Slim and Control IQ works it out during the night and I always wake in range.
I have to say I find the same for me too.