Medtronic 670 micro bolus settings in automode


(Jean) #1

Hi everybody,
I read several topics on the Medtronic 670 automode but I didn’t find solution to my question.
I’m in automode since now 10 days and still facing issues during night. Due to high BG around 2 am, I was fussing that pump will increase the micro bolus but apparently pump delivery is stucked on 1.5u/h and after 4 hours ask me for BG to remain in automode. It s clear that I really need higher micro bolus during the night and don’t understand how to solve this block. Very frustrating because for the rest of the time during the day, it is working perfectly.
I heard that exit of auto mode for some days will reset the calculation of the max basal rate, is it true?
The result is that combining with very small correction bolus requested by the automode, I usually need 10 hours to come back in acceptable range.
I’m lost and I do t know what I have to do. To be more patient and basal rate will be adjusted with time to finally provide me the correct amount and clear the Max 1.5?
Should I exit of the automode for couple of days ?
For the moment I have IC ratio of 9 and AIT of 2,5h

Your suggestion will be very much appreciated.


(joe) #2

Are you mixing the pumps delivery basal with the parameter of “max basal”. The pump may have a limiting parameter. What is the pumps max basal rate set to? Older pumps used the parameter and would not allow you to deliver a basal rate above it. Useful when you set a temp basal as a% of normal basal.


(Jean) #3

I’m speaking about basal delivery. I understood that max basal setting has no effect in auto mode


(Jean) #4

Max basal setting is 4 for the moment


(joe) #5

apparently not. the user manual is not clear what limits the maximum basal rate but there is one. There is also “safe basal;” which is another selected basal rate, in auto, when there is a algorithm sensor issue or actual sensor issue.

Not the greatest manual if it cant tell you exactly… imo


(Kathy) #6

Hi @Jbdeb Jean. I’ve been on auto mode for about a year now.

What you are dealing with is the automode calculated maximum micro bolus rate. This rate (along with the minimum micro bolus rate) is calculated every night at midnight based on your last 6 days on insulin usage and the corresponding sensor values and a number of other factors.

If you are running at your calculated max micro bolus rate for 4 hours AM will want a bg to make sure you are really still running at a level needing the max rate.

Remember, this system, in automode, is really different than other pumps. There really isn’t a basal rate in the traditional sense. What you have is AM giving you micro boluses of insulin every 5 minutes based on your sensor readings and how you reacted to the previous micro blouses.

Over time automode will figure you out but in the beginning, AM is very conservative with dispensing insulin as one of the primary goals is to keep lows to a minimum. While Medtronic says it takes about a month to figure you out (and you to figure AM out), it took me 3 - 4 months.

There are very few parameters you can adjust to influence the calculations. The two that you can are the carb ratios and active insulin time. You might want to talk to your endo or trainer about the active insulin time. A shorter AIT allows AM to be more aggressive. Tweeking carb ratios may also help. Also if AM recommends a correction, take it. This helps AM learn what your correction needs (AM has its own insulin sensitivity calculations too) are too.

Best advice is to be patient and to work with your endo or trainer to get the settings right for you. And you do need to be really, really patient.

Sorry for the ramble. I do understand how frustrating it can be. But it does work.


(Jean) #7

Thanks a lot Kathy. For sure it will be very useful to understand how pump works.
I decided to come back in Manual to find correct basal scheme. I found it with 3 night correctly managed and now keeping this I will come back in auto to see improvements, if any.

Again thanks a lot


(Treva) #8

I was going to “ditto” Kathy. It learns your patterns, and after a bit of time will zone in on where you need more basal insulin. I got very tired of middle of the night alarms for the first 2-3 weeks, and got into set-up to increase my max bolus, which of course does nothing for this issue. Then, my educator suggested we decrease my active insulin time. Although I knowfrom lits of years of monitoring that insulin is on board for me at least 5 hours, we dropped my active time to 3.5. It helped a huge amount. We also adjusted my bolus ratios for different times of day, Although I’ve been 1:10 since I got my first pump in 1992, I agreed with her that my body wasn’t responding the same now as it has for years, so I trusted her even though my brain was yelling “No!” All this to say that you should stay in clise contact with your educator, and don’t feel like you know much more than they do. Ive had T1 for so long, I do tend to think I know what I need more than anyone. Not so right now, and Im grateful for my CDE’s knowledge & experience. Never worry about “bothering” them. They will lead you to a much smoother path, and have heard your issues from others before you. Good luck! You will be so glad for this technology very soon! Hang in there!


(ANDREW) #9

Jean,

I’ve been on the Medtronic 670 a little over a month. I have experienced a lot of the same issues you have. I will say that after reading Kathy’s and Treva’s reply it has given me some hope. I’ve been bull headed and refused to get out of auto mode and I have noticed that it’s not waking me up as often.