Medtronic 770 insulin pump

I have a question. What do manual basal rates have to do with automode. I have been having alot of low bloodsugars since the warmer weather came. Do I need to adjust my basal rates in manual so that I am not so low in automode?

Most likely yes, that is how Tandem IQ works.

Best to contact Medtronic or your endo for help.

If you are going low, without exercise, then likely you need to lower your settings.
There may also be sensitivity settings to tweak.

How many days does it take for the new basal rates to make a difference in my sugars?

Changes to basal should take effect immediately, and depending on how much you change, will take one or more days to be noticeable in manual mode.

This link may be helpful.

The following from 2nd link says this:

  • Be patient. The algorithm needs to “learn” your needs. It can take 2-3 weeks. Remember, the device is not intended to replace finger stick checks; it is designed to remove some diabetes decisions and improve glycemic control. This will take more “device management” but less “diabetes management.”
  • The more accurate and honest you are with the carbohydrate grams programmed and eaten, the better (and faster) the pump algorithm will respond.

When the warmer weather came, this may change your insulin needs, but automode may take 3 weeks to recognize and adjust.

Also, from prior posts, I think you indicated your insulin usage is relatively low. This means automode may have less/slower affect.

Per the links, it appears automode relies more on actual past usage, rather than manual basal settings. This is different than Tsndem, where personal profiles are set up and can accomodate different scenarios.

On a pump (any pump) assuming the basal comes from the pump the time is the same as your “insulin action time”; the time it takes a bolus to run out of your system.

That’s because boluses and basals are all the same with a pump; the pump just injects insulin. Insulin lasts only a few minutes once it reaches your circulatory (blood supply) system, so the time delay is entirely the time it takes for the injected insulin to make it to a capillary blood vessel.

Unfortunately that means it can vary a lot; T1s report delayed or changed insulin action with lower activity, different times of day, different times of month, different times of year, anger levels, depression…

As @MM1 suggests, be careful and, if you haven’t done this before, you might want to talk to your endo (a diabetes educator probably won’t help, but you never know). Some people, even after 30 years, seem to have residual insulin production and that complicates thinks enormously (not that it’s a bad thing!)

Nevertheless I’d work to establish a basal level along the lines of mysugr.com link (thanks @MM1; great ref) and feed that information back into the pump.

I am in automode and I was having alot of low bloodsugars. Someone suggested to lower my basal rates. Now how long does it take for automode to realize that I dont need as much basal insulin as I was getting before?

Per the link i posted and quoted, it takes 2-3 weeks for pump to learn your basal needs.

“Be patient. The algorithm needs to “learn” your needs. It can take 2-3 weeks”

This is different on Tandem pump, which uses the programmed basal as starting point to adjust.

The auto mode bases its decisions on your glucose readings.
If you are slightly high it gives more basal. There is always a delay in injecting insulin and how long it takes to hit your blood stream. That’s true in pumps and injections w a syringe.

Auto mode and CIQ are really just backup systems for me if I’m not paying attention for a while it will take over and keep me pretty much in range. But if I’m looking at my pump and it is headed out of range, I will often fix it myself.

It’s easier on tandem to do that. I think I remember you need to switch off auto mode to make adjustments manually on Medtronic. You don’t need to do that in Tandem

But really they both work in a similar way.

On the Medtronic website it says that the pump doesnt “learn” patterns. Maybe it is different from what you quoted previously. Maybe my reductions are starting to work as I am not having as manylows. Through the night my basal rate is set at from 8pm until 3am I am set at .025. I go a little high 3 hours after supper 8p.and don’t usually go down until 9pm.The lows that I am having are around 4am 430am and I dont test with the meter but I suspect they are close because when I wake at 6 am the number is pretty close.

I may be wrong, but I was led to believe that settings in manual mode have no effect on auto mode algorithms. You get to choose which mode you want to be in and one is independent of the other.

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I was having alot of low bloodsugars and aomeo ne suggested that my basals might be off. I think it was MM1 who told me that so I went through my basals and reduced it where I was having the most trouble and so far it has been good. The lowest I was today was 4.6 by the sensor so it might have been a bit higher by the meter. I haven’t done any basal testing either. That was one of my reasons for wanting to go on this pump to begin with. I also wanted one that gets updated so I wont have to wait until my contract time is up.

D’Etta Meloche

Maybe just misleading terminology. My link was from a diabetes educators instructions on medtronic automode. I have not used medtronic since the older 523 model.

Hope you find whatever works for you.

The basal isn’t a pattern - it’s a fixed number determined by the production of glucagon by our alpha cells (which has to be counter-balanced by injected insulin). It’s pretty much “0”, but because many of us, maybe most of us, have alpha cells but no beta cells we have a constant release of glucose which has to be re-adsorped and this requires a constant supply of insulin - the basal.

I think the meaning of pattern is that the pump learns how sensitive you are to basal changes to change BG. It knows sensor reading and BG trend and decides if basal change is to be made each 5 minutes based in prior history data. Documentation suggests the 770 pump needs 3 weeks of data to be in auto mode to “learn”.

That was a very good explanation of how it works. Thankyou

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