CGM help

[tigger]

So I just got a CGM on Monday and so far I have been through 2 sensors and one sleepless night.

The problem is it kept on saying I was low when I was 5 or 4 and buzzing 5 times between 1.30 and 4. It then refused to accept my calibration I snoozed it for 2 hours and it rejected the next calibration and that was the end of the sensor.

So the next morning I put in another disabled a lot of the alarms and called meditronic who said they'd send me a new sensor. I was very careful about only calibrating when it wanted me to even when my reading was different until it called for the next one when it said I was hypo and my meter and body said not. It rejected it. So I ignored it ate supper, waited an hour and tried again and it rejected the 2nd reading and bang went the sensor. Another conversation with meditronic who talked me through all the options agreed I'd followed the book then suggested I did some complicated equation with ISIG which I didn't understand.

I'm wondering if the reason it doesn't work for me is because it's based on an algorithm of how newer insulins should work and I use animal insulin (porcine) which acts more slowly. The rep claimed he thought that might happen when I was given it but he said the same about the pump and I knew that wasn't and isn't right.

@azure and @CarbsRok have you ever had a CGM and had this experience? Or is it just (fingers crossed) malfunctioning sensors? Or any other reason?

 

[CarbsRok]

I'm wondering if the reason it doesn't work for me is because it's based on an algorithm of how newer insulins should work and I use animal insulin (porcine) which acts more slowly. The rep claimed he thought that might happen when I was given it but he said the same about the pump and I knew that wasn't and isn't right.

Hiya, your rep is talking through his rear end I use the Dexcom sensors with no problem at all. I can't help with the problems you are having as don't use Medtronic, sorry.
Only problem I did have when the sensors were awful this was down to a faulty transmitter. The transmitter was replaced free of charge and everything is as it should be.

 

[azure]

@tigger I've never used a CGM but I can't see why the porcine would make a difference. The CGM is just measuring blood sugar and doesn't know what insulin you've taken.

I'm glad CarbsRok has confirmed this because I didn't know for sure, but logic says the insulin wouldn't matter.

I wish people were more informed about animal insulins! You'd think they were something bizarre, but the porcine insulin is much closer to our own insulin than any of the analogues which aren't actually insulin at all, but an analogue of it.

I hope you get your sensor problems sorted Having a disturbed night like that is no fun at all.

 

[tigger]

Thanks @CarbsRok . The way the cgm works is it tracks your bg and then you can set it to alert you if it goes low, if it is going low and it can also suspend your basal if you're low and prior to it to allow you to avoid the hypo. That's the theory...... Does the dexcom work in a similar way?

The issue I was having was it was saying I was low either when I wasn't or quite a while before I got there e.g. 20 mins when I only had the alerts set for reaching low not anticipating it and i deliberately set the low level at 3 to cater for error.

The hospital are as ever clueless. When I described the situation one of the nurses said "our big fear is the pump wouldn't work with your insulin". Obviously the IDDT article didn't make any impact Maybe my 6.1 hba1c will have more of an effect.

I have a new sensor to try and I think I'll wait til next week and give it another go.

Thanks for the reassurance.

 

[CarbsRok]

Thanks @CarbsRok . The way the cgm works is it tracks your bg and then you can set it to alert you if it goes low, if it is going low and it can also suspend your basal if you're low and prior to it to allow you to avoid the hypo. That's the theory...... Does the dexcom work in a similar way?

The issue I was having was it was saying I was low either when I wasn't or quite a while before I got there e.g. 20 mins when I only had the alerts set for reaching low not anticipating it and i deliberately set the low level at 3 to cater for error.

The hospital are as ever clueless. When I described the situation one of the nurses said "our big fear is the pump wouldn't work with your insulin". Obviously the IDDT article didn't make any impact Maybe my 6.1 hba1c will have more of an effect.

I have a new sensor to try and I think I'll wait til next week and give it another go.

Thanks for the reassurance.

Dex obviously doesn't suspend insulin as it's a feature of the pump you use.
But yes it does alarm when blood sugars are to low or to high.
You have to remember there is a 20 min lag in sensor and finger stick testing. So simple solution is to set the alarm to go off at 5 and your blood sugar if dropping will actually be more like 4.5 so treat and stop the hypo before it happens.
@Flowerpot uses the same pump as you and sensors but doesn't use animal insulin. Hopefully flowerpot can help you out with the sensors.

 

[Flowerpot]

Hi @tigger

Have you got Smartguard -suspend before low - or suspend on low on? If Smartguard is on then the pump can suspend a maximum of 3.9mmol/L above the low suspend value if it works out you are likely to hit the low suspend value in the next 30 mins so if your Low suspend is set at 3 then Smartguard could cut off basal at 6.9 if you are falling quite rapidly. If suspend on low is on then Smartguard won't work and the pump will only suspend delivery when you reach your low level - in your case 3.Only one suspend feature can be on, either Smartguard cutting in at higher values to stop you reaching hypo or suspend on low when you are hypo.

You can choose times to silence the alarms so they don't alert you in the night although the pump will suspend basal in the same way and you are only aware in the morning. Go to Sensor settings, then Low settings and you can set time periods where you don't want to hear the alarms. I only found this recently as I was having 8+ alarms through the night.

I have only had 2 sensor failures in 4 years and not through calibration errors so I can't help you on that. I sometimes gently push the area around the sensor to make sure it has enough interstitial fluid around it to keep good accuracy.

Hope that helps a bit, if not I'll try again! Smartguard certainly does take a bit of getting used to and I have set my low glucose at 3 to prevent it kicking in at too high a value. I hope you get better readings from the new sensor.

 

[tigger]

Thanks lot. Yes it does have smartguard but I'm going to disable that the next time to see if I can make it work on the basic level first and then see how the other bits work.