Tandem correction factor

This past Saturday, I had a sever hypoglycemia and ended up in the hospital for observation. I do have hypo-unawareness and have had low that effect my behavior and perceptions beyond just being confused. But this one was on a different level.

First my question: If the correction factor is set too low (high ratio), can that result in over treament of a high bG? Maybe Control-IQ can’t lower the bG and gets more aggressive. That is the best theory I can come up with to explain this incident. It’s either that, or it’s one of those inexplicable things. I prefer explanations…

The detailed backstory:

I had breakfast about 7 am and the next thig I know I’m laying on the couch surrounded a half dozen EMTs and it’s 4 pm. When I came around I thought I hadn’t eaten breakfast after bolusing. But it was not that simple.

Chronological order with a bit of reconstruction:

Got up. Fed the Dog. My bG was high, so I bolused for breakfast + correction. I waited about 15 minutes, then ate a bagel. Shortly after that, my sensor expired and changed it and started the warm up. I kind recall feeling tired and going back to sleep, which is my routine on the weekend after feeding the dog. I don’t recall if I did something else before that or which couch I lay down on.

Next thing I remember, I’m having a nightmare. There are a half dozen faces very close, looking at me very intently. The faces all seem to be the same. They were all wearing the same blue uniforms. I feel I am trapped in a net. I struggle and break free. Feeling relieved, I roll over and go back to sleep.

Then I start coming around. Everything is strange, I don’t know where I am or why all these people are so concerned. Then it dawns on me that I am confused and these people are EMTs and figure I probably had a low or something. I reach for my pump, but can’t figure out what it means or what to do. More and more, over a stretch of ~20-30 minutes, I start to get a grip and things start making more sense. Our best friend is there. My wife is on the phone, calling from out of town. They ask when I last ate and what I had. I thought I hadn’t eaten at all, but I did take my breakfast bolus. After some “advice,” I relent and let the EMTs take me to the hospital.

After, I was told: my son found me laying on the couch. Thinking I was napping, he started talking to me. I responded with gibberish. He went upstairs and could hear me talking to the dog in regular English, which compounded his concern. He called my wife, our friend and 911, but I don’t know in what order. When the EMTs arrive, I am combative, thrashing and uncooperative. They can not get an IV in me so they try to force oral glucose gel. There was a mess of it all over my face, but they must’ve gotten some in. Then I passed out and they were able to get an IV in and test my bG. It was 44. My son said they injected something into the IV tube. I’m thinking I got dextrose and glucogon.

At that time, I thought I’d bolused for b-fast + correction. Maybe the basal was also elevated because I was high. Then I changed the sensor and the pump had no glucose readings for two hours and was unable cut the basal. With that much insulin on board, it wouldn’t have made a big difference, but may have prevented me breaking from reality and I might have eaten and/or taken glucose.

But after my bG stabilized and they released me from the hospital, when we get home, I notice a plate on the kitchen table and remembered eating a bagel. So why I did I go so low? A couple of day before, I’d been adjusting the correction and carb ratios. So I went to my profile and found that my correction ration was 1:18, where is was previously 1:9. I know exactly how that happened. I entered both the 1 and the 8, not realizing the the 1 is implicit and fixed. So I’d set it to 18. I must have just blew past the confirmation prompts.

But then I realize that would under deliver insulin and was less likely to cause a hypo. So maybe Control-IQ increased the corrections to a point where it was too much?

I don’t know what happened in your case. But I can tell you that I NEVER change more than one thing at a time on my pump (T2 w/ciq). One change, then a 3 day observation of that change. Then, if necessary, another change. Change more than one thing at a time and you don’t know which is responsible for any effect.

Also, I never change anything right before I insert a new sensor. I had a bad experience 2 years ago when I was in the 2-hour limbo during a sensor change. Went to the barn to feed the critters and felt myself going low. Thought I could take a couple of minutes more to finish chores and fell to the floor breaking my wrist. Was cognitive enough to get myself up and back to the house to call a neighbor to take me to hospital to have the wrist x-rayed and set. I was lucky that I still had some amount of cognitive ability. I now plan my sensor changes (and 2-hour wait) while I am in the house and not really doing anything other than, possibly, reading.


Thank you. Excellent advice! In fact the last change I made was several days before this incident. Yes, I was adjusting both correction and carb ratios and I shouldn’t have been doing both. I made the initial adjustments during the previous week. I continued adjusting the carb ratio for a few days and got them back to where they started. So by the time I made the last adjustment several days before the hypo, I was only changing the correction factor.

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You can check your history on the pump and see exactly what CIQ did (corrections, basal increase) and how much insulin you had given yourself. My Dexcom always reads high after warmup. It’s possible that after your sensor finished warmup it was reading too high and the pump gave you a bigger correction than you actually needed.

When I changed my sensor on Saturday I forgot to turn CIQ off during warmup. I normally stay in sleep mode all the time, but I think the lack of sensor readings turned that off automatically. So when my sensor finished warmup and started reading my pump was in normal CIQ mode, and it gave me a correction. I was busy so it took me a little while to check my reading and do a meter BG to compare. Of course the meter was much lower, not high at all, and I did not need that correction and I dropped fast, but I saw that I had IOB and was able to treat it. If I was busy and hadn’t noticed or asleep it could have been a lot worse. This is why I never change a sensor before bed. I like to be able to watch is during the first few hours and calibrate as needed.

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Wow, we really are all different, aren’t we? My sensor very often reads low (like 40 or below) for a few hours after warmup. I have to turn off Control IQ or it will completely turn off my basal insulin. The alarms are beyond annoying. Calibration helps, but doesn’t ompletely fix it.

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Perhaps your programmed basal rate is a bit high. So you started going low while your sensor was warming up and when your sensor started up it was reading higher than you actually were so your pump either did nothing because it thought you were in range or the senor was reading high enough that it compounded the issue with a bolus.

BTW, unless your son or friend handed the EMT’s your personal glucagon kit then they did not give you glucagon. They do not carry it in their kits but they can give it to you if someone gives it to them. You were given dextrose most certainly after you calmed down enough for them to insert an IV.

If you don’t have a glucagon prescription then get one ASAP you could be at risk of severe lows for awhile until your liver refills it’s glucose stores. There’s inhalable glucagon now that anybody could easily give you so the EMT’s don’t have to get involved and you will come around almost immediately instead of waiting for emergency services.

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On Maryland, paramedics are the only first responders who carry and may administer glucogon. I was using EMT generically. One of them may have been a paramedic. Regardless, I didn’t actually see it, just going by what my son said. I do take that with a grain of salt because he was totally freaked and his memory might not be clear.

Follow up: I saw my doc on thur, a pre-scheduled appointment. We concluded that my correction ratio of 1:18 was way too low. I’ve been using a pump for 15-20 years BEFORE they got bolus calculators, and that was a feature that I sought once it was available. I should’ve known right away that my CR was off. And I did eat after I bolused, but not enough, looking at the history. I had intended to eat more. Whether or not I stay cognizant is a crapshot. It didn’t help that I probably went low while I was asleep. Most of the time, at 40-50 I have mild symptoms and confusion. I recognize and treat it. On only a few occasions has it affected my cognition. And before now, I have never lost consciousness in about 50 years having diabetes.

She was going to talk to the Tandem rep the next day and ask if the CR is used for automatic corrections or just user administered. She said other pumps don’t and she thought the Tandem did.

Since I did loose consciousness, she strongly recommends, and I concur, that I keep a diary of my bGs every time I drive. That way when she fills out the MVA form about my fitness to drive and answers yes to having passed out, she put it down as a mitigating action. She told me about a patient who was testing with finger sticks and did this. She got in her car, tested, 124, and a few minutes later passed out and ran into a tree. Her bG was 43 when the EMTs got there. All of this was in a matter of minutes. It turned out hr meter was faulty, but because she could prove her diligence, her insurance rate did not go up and she kept her licence.