Medtronic 780G (really call MiniMed 780G). Adventures and misadventures of a newbie insulin pump user.

[Jhon Doe]

1.- Introduction.
My idea is to speak about all my experience with the pump Medtronic Minimed 780G and Guardian 4 sensor and Guardian 4 transmitter from the begining with them.
I don't write all at the same time. And If I see that you are interested, I will continue with the next parts.
I'll coment my experience with the new infusion set extender that I began to use 3 weeks ago too.

Regards
Doe

 

[Jhon Doe]

2.- The beginning, before the pump.
My experience will cover three years long in about a month and a half, but the instructor started teaching me in mid-August until early September, so I could say that there are only 15 days left until the three years are up.

Firstly, I should mention that I had high expectations for a pump that adapts to you after a learning period of at least a week (and this is because Guardian Mode, i.e. the automatic mode that makes decisions for you, needs at least a week's worth of data to be able to make those decisions). As I wouldn't be seeing the instructor every day, only once every 7 to 10 days, I spent more than 10 days in normal mode (Not Guardian mode).
In order to use the pump, you need to enter a certain amount of data:

-how much basal you need at each hour of the day and night. You can even indicate how much you need in minimum periods of 30 minutes. And every time I felt hypoglycaemia at night, I would ‘change’ that table so that Guardian mode would start from there. But be careful, the pump will ignore those values in Guardian Mode (it will start from there but analyses what is happening in your body and makes a weekly balance to recalculate the doses for the following week). And that's partly where its problems come from. From here on, I'll call it GuardianMode.

I used Levemir and rapid-acting insulin and injected myself between five and seven times a day: two Levemir injections, one in the morning and another at noon, and three more just half an hour before meals. The other two were based on the results of blood strip analysis. As my insurance company has always tried to ‘give you the smallest possible number of test strips’ (skimp on them), I couldn't test like crazy (so I never did postpadria/post-meal tests), I only did them before meals to know how much insulin to take, so that was three tests guaranteed. When I was in doubt, for example, if I felt my glucose was low or high, I would do another test, and also if there had been a problem when injecting (sometimes a few drops would come out when I removed the needle, so there could always be too much or too little insulin in my body). During the last pandemic, the person in charge of supervising the test strips decided that I was using too many of them and almost forced me to switch to the Free Style sensor, which I never ended up using because no one told me how to use it properly and because I didn't want to change something that I knew how to use. My diet was fairly consistent, even when I skipped meals, but because I didn't control my postprandial levels, my glucosylate values haemoglobin was very high, sometimes reaching and remaining (between 3 and 6 months) at over 8, even 8.5 (and even sometimes, even more so of this value). Between 7 and 7.5 is not ideal, but it is tolerable. Above that amount is too high. But, at end, this was better to obtain my pump, because in order to be prescribed (and approved by my insurance company), your values must be at least this high or higher for 6 months or more.

Note:

HaemoglobinA1c (HbA1c) (called usually glucosylate haemoglobin and shortening we called only "glucosylated") versus
Glycated haemoglobin (mmol/mol).​

Equivalence of values between both:
HaemoglobinA1c (HbA1c) ___versus____Glycated haemoglobin (mmol/mol)
Less than 5.7%. <----------------Normal--------> Less than 38 mmol/mol
Between 5.7 and 6.4%. <-----Pre-diabetes ---> Between 39 and 47 mmol/mol
Greater than or equal to 6.5%.<-Diabetes----> Greater than 48 mmol/mol

 

[Jhon Doe]

3.- The beginning, with the pump.

To start using the pump, you need to enter the following data:

-Set the basal rate, which is the number of units your body needs. You can enter this every 30 minutes, but of course, you don't have that data, so the pump training instructor and my endocrinologist calculated the Levemir units I was using and how much rapid-acting insulin they corresponded to. I used the pump for several days without insulin (and I continued to inject Levemir and Rapid), but the pump did collect the values to check if there were any peaks up or down so that I could correct them.

To use the Bolus Wizard feature, consult a healthcare professional to determine the personal settings that should be used. The carb ratio, insulin sensitivity factor, BG target, and the active insulin time are needed to complete the setup.

-Carb Ratio. The carb ratio setting is used for food bolus calculations.The number of carb grams that are covered by 1 unit of insulin.

-Insulin Sensitivity Factor. The insulin sensitivity factor setting is used to calculate correction bolus amounts. The insulin sensitivity factor is the amount that BG is reduced by 1 unit of insulin.

-BG Target. The Bolus Wizard feature calculates the estimated bolus based on the BG target range. The high and low values set are the values to which the BG is corrected. To use a single target value rather than a range, set the same value for the high and low value of the BG target.

If the BG reading is above the high target value, a correction dose is calculated. If the BG reading is below the low target value, a negative correction is calculated and subtracted from the food bolus

-Active Insulin Time, Active insulin is the bolus insulin that has been delivered by the pump and is still working to lower glucose levels.The pump uses the active insulin time setting to determine if any active insulin is still in the body from prior boluses. This may help prevent hypoglycemia caused by overcorrection of high BG. The current active insulin amount appears on the Home screen and includes only the bolus insulin received. Consult a healthcare professional to get the active insulin time that best represents the insulin type used and the physiological insulin absorption rate.

When the monitor (the person who taught me how to use the pump) saw my graphs showing the effect of Levemir, he told me that the pump would never give me that, and although I didn't believe him at the time, I later understood.

Most of my blood sugar pattern was flat except after meals. But with the pump, it's always sawtooth. So it's true: without eating, my blood sugar levels were flat. The only bad thing, which has always thrown my glucose out of balance, is after eating: while I'm not eating, everything is fine. After eating, that's another story.

And why are they sawtooth? Well, it's very simple: because the pump reacts to glucose levels and, in Guard mode, it's very conservative. It tries to compensate for the rises (but as the information is always delayed because interstitial glucose lags behind blood glucose), it's difficult to balance the rises and falls. And then (I got the table of insulin units to inject, based on the glucose measured), the pump pays more attention to you when administering insulin if you indicate the basal glucose. In fact, it sometimes asks you for it (or often, in my opinion), to check that the glucose obtained by the pump is sufficiently accurate and says it will use it ‘to calibrate’ the values provided by the sensor.

Another lie: I have never seen it adapt completely (or at all) to the values I indicate. What happens is that sometimes the glucose differs greatly (what it measures is much higher/lower than reality, usually higher). If it is less than 20%, it tolerates it. But if it is higher, it does not accept the ‘calibration’ and asks you to repeat the analysis within 15 minutes and tells you to wash your hands (as if you had not washed them before). If this process happens to you several times in a row, that is not good, as the pump will indicate that the sensor is not working properly and tell you to change the sensor. Also, if you do this when your glucose rises sharply due to something you have eaten, the above may happen and it may tell you that the sensor is broken. To supply blood glucose to the pump, it must be at a time when your level is as flat as possible so that it does not indicate that the sensor is broken and that you must change it.