Dexcom G6 had wildly off reading!

General
41

Hi Patricia @Pmaddix, I have looked about trying to find a pump suitable for severe visual impairment but didn’t find any. During a period of very limited eyesight, since been restored through surgery, I checked out all available pumps and found the easiest for me to use is the Tandem t-Slim x2.

If the Tandem Control IQ is approved by FDA, this pump combined with Dexcom G6 CGM has definite potential for regulating body glucose level with minimal user intervention - user will still need to enter food carbohydrates. And as Joseph @marinekeeper posted, you can monitor and know your glucose with an iPhone.

If you can contact an upper-level manager at Tandem, and plead your case, you might be able to get some tool to assist you.

42

Dennis, what was it about the tandem screen that made it quite usable with low vision? Perhaps all the letters and numbers and symbols are very large with a high contrast background? The only things I can see on the med Tronic pump are the bolus dose as I dial it in. I worry about the tandem as it is a touchscreen and if you make an air and touch something you could be in trouble I currently use the Dexcom G5 and the phone app on my iPhone reads out loud all the information to me as well as the blood sugar value is very large and bold and high contrast.

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43

My vision is not impaired, the Tandem screen is very easy to read. Dark background with bright contrasting colors for all the different info the pump is displaying. There are safeguards to prevent accidental bolusing or changes to settings on the Tandem. The safeguards are not a big deal to get through, once you’ve used the pump, you quickly understand why they’re there in the first place.

44

Patricia @Pmaddix , Jason @Jason1 answers just as I would - the best is the contrast, dark background and overall clarity. The safety features, although sometimes being a bit redundant help me feel confident that what goes in is really what I want.

I had used three model Medtronic pumps before changing to Tandem and the difference in my ability to see was significant under all light conditions. The Tandem representative let me “play” with a t-Slim, practice entering values and move about so I could see the screen under different light conditions. Holding it next to my Paradigm pump I was quickly sold.

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45

Thanks. That is very helpful.

46

Patricia @Pmaddix, the one part of the Tandem display, that I forgot to mention, that is “difficult” for me to read is the screen that is optional showing how the algorithm calculated/ adjusted the insulin dose. \I don’t often look at this screen because automatically I’m doing the arithmetic in my head before the pump completes the calculation - just something I’ve ben doing for years.

47

With the tandem pump do you have to enter your carbs and let the pump calculate the bolus for the meal or can you just enter the dosage that you want and skip that step?

48

There’s a few choices. You can enter your carbs and BG or just input how many units of insulin you want to bolus.

49

I switched from the Minimed Guardian to the Dexcom G6.

I hated all the calibration alarms waking me up through the night, feeling tethered by a “ball and chain” and pump failures at the absolute worst possible times.

That said, all the calibration alarms and hassle kept the sensor very accurate but the Guardian lowest basal closed loop BG set point was much higher than my body likes to ride at.

I moved to the Dexcom G6 because I wanted to have peace of mind to sleep through the night, predict and prevent lows, and less of a ball and chain than The MiniMed system, and to try the DIY Loop and set my BG basal set point lower.

The conclusion I’ve come to since switching to the Dexcom G6 sensors is that it is unpredictable and wildly unreliable. I cannot trust the Dexcom G6 to base treatment decisions on and definitely cannot trust the sensors to used in a semi closed loop insulin pump.

The pros is that it “can” help indicate and prevent hypothermic reactions.

My first box of 3 sensors went something like this:

Sensor 1: ~97% accurate
Sensor 2: ~80 accurate
Sensor 3: ~40% accurate or worse

I define accuracy as “Any reading, within a hour period, that will cause a correction bolus to be administered or withheld that would result in BG being out-of-range”.

so, if anytime within an hour I get a reading that would falsely indicate a correction bolus, or lack of, that would’ve resulted in a hypoglycemic or hyperglycemia reaction the pump has failed that hour.

I’d like to expand on this definition in the future to include a severity metric. Like “any correction bonus that would result in BGs being more than 40mg/dl

Sensor 3 was a nightmare. Everyday it wanted multiple calibrations but still could never hold an accurate reading. The best I could get was 30/30 and then an hour later it would be 60-80 mg/dl off again and I’d be fighting to re-calibrate.

So, I’ll simply write sensor 3 off as a failed sensor and not consider it in my overall assessment of the G6.

That leaves us with 2 sensors, 97% and 80%. Making treatment decisions that are life and death with inaccurate data 3-20% of the time is a problem.

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50

This AM my D6 said my BS was 300! I used that figure on my pump and it gave me 5 units of humalog. Decided to check with my meter, and it said my BS was 145! I panicked and suspended my insulin, and ate a bunch of carbs to try to counteract my humalog overdosage, then my husband took me to ER. My BS seemed to be stabilizing, after all I ate, so the hospital nurse told me to resume my insulin and go home.
So far I have been okay. Any time I have an out of norm range, I’m gonna check my meter first before giving any insulin.

51

Yikes! It only takes one bad sensor to kill you… But they have who knows how many bad sensors and most users don’t even know it. I don’t dare make treatment decisions from my Dexcom G6 anymore. Since I wear the G6 and test I get to see how terribly off the sensors are.

So far my last 3/3 sensors were bad. I think I’m at 6/8 sensors being over the tolerance (20% which is way to much!). I’ll keep calling Dexcom getting new ones and calling them back letting them know that I got another junk sensor.

I think I’ll try the 2x per day non code calibrations next time and report back.

52

I’m curious @Wolfman, what testing method are you using TO CONDEMN the G6 Sensor that has been proven extremely trustworthy? Personally. I find the results displayed by my sensors to be perfect. Today I certified received results of laboratory work I had performed and the glucose level of blood drawn my veigh EXACTLY MATCHED the result displayed by my DexCom G6 sensor - not even one (1) milligram per deciliter [mg/dl] difference in values.

I strongly suggest that you validate the methods you to CONDEMN a proven device without first validating your device(s) and your methods for performing those tests.

53

Yes…my son just had a 100 point difference with his Dexcom. It was in the 1st 24 hrs of a new sensor. We calibrated and it eventually evened out. I wear a different sensor, and have the same issue at times. Although they say no need for fingersticks and calibration, it’s not really true. My opinion is that sensors are wonderful technology and so useful…but not always reliable.

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54

@Dennis, it’s a gross exaggeration to claim I’ve condemned the G6. I simply shared my experience with recent sensors being off, as have others, including some of the medical professionals at my Endo clinic.

And I’ve been a type one for over 21 years now and understand how to test my BG accurately. I wash my hands, let them fully dry, don’t take other medications or vitamin C, and I use the highly accurate Ascensia contour BG test strips.

I do understand that interstitial fluid glucose sensor levels will never be as accurate as blood glucose levels by nature. That said, even if the G6 is 95% within 5mm/dl of actual blood levels, it’s the 5% that can be deadly. Dexcom recommends testing you BG is you get an unexpected reading anyways so I suppose this is fine for T1Ds with great BG control.

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55

Hi Amy! I have a problem with the G6 reading low, too. This happens at night when I’m trying to sleep. I’ve determined that the problem is me. You see, I always insert the sensors in my stomach area as recommended. This is actually a requirement of the FDA and of Medicare as I understand it.
The problems are with my sleeping positions. I have always been unable to sleep well lying on my back and that leaves my left side, right side and stomach. I have a pinched nerve in my left shoulder such that if I lay on that side for more than a couple of minutes, my left shoulder and elbow area begin to aches like a toothache.
I’m OK lying on my right side. I actually prefer to lie on my stomach because I have lumbar stenosis and that position feels so good. But (there’s always a ‘but’), when I lie on my stomach, the Dexcom G6 almost immediately begins to read low by 40 or more and that sets off the low alarm. If I roll onto my stomach while I’m asleep, the low alarm wakes me up as it should. The G6 will correct itself in 10 or 15 minutes if I roll off my stomach. The problem gets worse then as I usually have trouble falling back asleep.
As an engineer, I can’t fathom a system where a person is required to use the stomach for a sensor site, yet where the system malfunctions if the user lies on their stomach!

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56

When I used Dexcom G5, I wore sensor on my belly for over a year and had wildly inaccurate numbers. Even considering the expected differences, it was horrible MOST of the time, especially trying to sleep. HOWEVER, when I went to Medronic Guardian, I wore both sensors on my arms and it was like magic. VERY good accuracy immediately and they both stayed that way. I wore both on my arms just to see which was better, until my transmitter died. They both were about the same. So, for ME, it had something to do with body placement. If the rule with Dexcom G6 is that you can only wear it on the belly, I wouldn’t be able to do it. That area does not work well for me with sensors. This is sitting, standing, walking, etc.

I wonder where they got the idea that avoiding finger sticking was such an awesome thing. For me, better accuracy, less failures, etc. are more desirable than not finger sticking. To me, finger sticking is no big deal. In fact, to me, it seems like a good precaution to keep things tight. I wonder if there are a lot of Type I’s who told Dexcom their most hated chore was finger sticking. I’ve never known any Type I who felt that way, but, I guess there must have been a bunch out there.

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It’s inane. The two hour warmup is ridiculous as well. I test 4-5 times during those two hours now because of how quirky control IQ is without readings from the Dex. Medicare took the no fingersticks required and do not cover strips anymore for anyone using the G6 starting in January. My worry is that most health care insurances use Medicare guidelines for their coverage. I hope Kaiser Permanente doesn’t follow this one because it’s stupid not to cover a hundred strips a month at the minimum.

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Before I started on the G5, I was taking as many as 10 finger sticks a day. Now, with the G6, I still take maybe 4 or 5 a day. It always amuses me that so many folks with and without any type of diabetes fear them as well as injections.
When I was first diagnosed at the age of 12 the only syringes were the big glass ones with a glass plunger and removeable needle. The disposable ones hadn’t been invented yet. You had to boil the thing at least once per week and store it in alcohol in between. The bore of that needle was probably large enough that you could drop three or four of today’s disposable syringe needles through it at the same time! My mother was taking insulin at the time so she was my diabetes educator. She was probably a Type 2 diabetic, but at the time that was all there was. I was injecting myself from the first day.
There were no finger sticks then, only Lilly Tes-Tape and some large chemical pills (can’t remember the name) that were used to test a urine sample. The doctor would occasionally order a blood test for “sugar”. For me this usually was done on a Saturday morning when a large test tube of blood was drawn. We would then call the doctor’s office on the following Monday afternoon to get the result! There was no such thing as an A1C test that I know of either.
We’ve come a long way for sure!

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59

The commercial name was Clinitest but the “pill” was actually copper sulfate. The company was Marshfield Labs. I was not a big fan.

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60

I just had a crazy different reading that I’m currently trying to recalibrate my g6 over. My sensor woke me up saying I had an urgent low so in my half asleep state I chugged a juice box then when I started to wake up I realized I did not feel like I had an urgent low so I checked with my meter and it was 268! I’ll probably just have to insert a new sensor cause that’s insanely off and I’ve never had that happen before and have been on a dexcom for three years.

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