Minimed 640g Insulin Flow Blockage Repeatedly - Help!

[Patch13]

Hi. Today I have changed my cannula / set about 5 times so just wondering if anyone has had a similar issue / could suggest anything. I'll start at the beginning...

My first 2 Cannulas failed today and when I took them out they were bent. This may have been a site issue due to scarring as I was using my love handles which I've been using for a while.

So I changed my cannula for a 3rd and 4th time relocating to my stomach which I haven't used much in the last 9 months due to being pregnant. Pump told me again that it was blocked.

Each of the error messages have occurred when I have bolused for food. During just having my basals my pump hadn't sent me any error messages and my sugar had been ok today - not stupidly high like I would expect if I had not got any basal insulin.

Phoned Medtronic for help and spoke to someone in America who ran some 'tests' eg asking me to put some insulin through the tubing and see if it comes out etc, which it did. Basically told me to see the doctor to get my sites checked and that was pretty much it.

Luckily managed to contact my DSN so will be going to see her tomorrow but any advice / experiences are welcomed!

 

[rockape37]

Not had any erorr messages on my pump yet and only been on the pump for 8 weeks now. However yesterday morning i did a set change including a new reservoir. My bg's were all good till 1600hrs when i had a bg of 26! I did 2 corrections with very little change before deciding i had better do another set change.
Checking the canular there was a small kink and i mean small. It must have been enough to restrict the flow of insulin.
I did however reconnect the canular to the set and used a plunger to see if insulin came out of the canular which it did. Having said that i suspect that the pressure used by me would have been far greater than the pump bearing in mind that the pump secretes steady measured amounts.

Not an answer to your question but i think it goes to prove that the tiniest of kinks can cause insulin flow issues.
How the kink occurred i really do not know.

Regards

Martin

 

[gillkin]

I've had the same pump as you for over four years now and never had that problem, you must be really fed up having to change the cannula so many times in the one day.

could you perhaps use your upper arms or legs as possible sites if you don't want to revert back to your stomach?

Best wishes

Gill

 

[Juicyj]

Hi - how are you today ?

What infusion sets are you using ? I was on the mio which I did have some issues with but mainly due to the fact it was causing lumps at the site so am now using the 'sure t' which is a steel cannula set, very easy to apply, short tubing and less inclined to kink, it's much more effective that the mio which I think is too long and you are never certain if i'ts connected properly, if you've suffered from scarring then the sure t would be much more effective for you, you simply pinch the skin and insert the steel direct, no pain but will make you feel much more confident it's inserted correctly, change every 2 days but i'm sure it would last for 3.

Mention it to your DSN but think this would suit you much better

 

[Patch13]

Hi. Thank you both for the comments. I'm really glad to hear this is not a normal occurrence as with my last pump (not Medtronic) this never happened!

Gill - I'm happily using my stomach again now (since yesterday) but I might try my arms if I get more problems. My legs I found awkward as I kept knocking the cannula out.

 

[anniehi41]

I use steel cannulas and a different pump and I have only had one occlusion in the four years I have had a pump, however I have noticed that if I change my cannula set just before a meal and then bolus for the meal this is the situation when my BG will rise, just as if the bolus hasnt been absorbed at all. So, I actually avoid changing my set just before a meal now. I try to let the basal drip in the new site for a couple of hours before a meal bolus.

 

[Patch13]

Oh that's interesting anniehi41 about the raising of BG if you change a set before a meal. I may ask to try steel or slanted Cannulas to see if this makes a difference. Always used plastic straight in Cannulas & never had a problem with previous pump.

 

[yingtong]

I've been on the 640g for 18 months and fortunately have not had a problem,I wish you luck in sorting it out.

 

[Patch13]

Had another blockage today so my DSN has insisted they replace it. medtronic think the Cannulas may not suit me (despite having used them for 3 months no probs) so I am also going to try out slanted Cannulas to see if that makes any difference as my sites are apparently fine too - DSN checked. Thanks for the help/sharing your experiences everyone that replied

 

[jackwolt]

I have had three bouts of ketoacidosis and a couple of near misses. Each time I have found that the cannula has not inserted correctly and is lying at 90 degrees between the sticky pad and my flesh. I think I have figured out how this happens:
If you pull on the tube to guide it into the nick the whole pad can lift. As you can see, the cannula lifts away from the steel needle and, without support, can bend over. It does not take much of a pull to do this. There is no FLOW alarm as I think the insulin just seeps away through the pad. A possible solution to this may be to make the nick a much deeper slot so that the angle of the tube is not so acute and the cannula would not lift so easily.
I have used approx. 650 of these MIO infusion sets (MMT-945) and have only had 1 Flow failure. I had an immediate FLOW alarm and just changed it without any further investigation.

Hope this helps.

 

[tigger]

I had this problem with quicksets. Some were fine but a lot would be seemingly ok and then i'd bolus and get the occlusion message. Could be a faulty batch. I switched to slanted and steel but am now using mios round my back and having a much better experience. Good luck with solving the problem. I prefer calling in uk office hrs as the US ones always sound too script like.

 

[AmandaD]

I use Mio sets and have only had a few kinks usually after a high blood sugar that won't come down. I use my sides and just below the boob line and my stomach is ****.

 

[dtennant9]

Hope you got everything sorted @Patch13
I had my first 'No Delivery' alarms on my pump yesterday and can see no reason why this happened so I would be interested to hear if you found a solution.

 

[IanRA]

Hi, I am having repeated problems with Insulin Flow Blockage warnings with my relatively new Minimed 640G. This has become actually quite life threatening on a couple of occasions, especially when it occurs while I am asleep and awake to find my BGL off the scale. I reported this to Medtronics, who then asked all the usual diagnostic questions and had a complete history of the pump failure. They sent me a new pump. Meanwhile, I reverted to my Medtronics Minimed 722G, which has never let me down, in spite of 8 years of continuous service. The replacement 640G is again showing the same issues.

There are other issues here too. But I think I can eliminate one of them. At the suggestion of my diabetic educator I replaced the Silhouette infusion sets with the Mio. The Mio does not have the robust anti-kink tubing of the Silhouette, the tube is hollow whereas the Silhouette tubing has plastic threads internally which prevent blockage with kinking. The other problem with the Mio is the tendency for the plastic cannula to fail entry into the skin. Indeed the insertion needle will at times penetrate the cannula. (Photo's attached). This inspite of careful preparation and attention to detail when inserting. I don't know why this happens but others report similar issues. (Photo attached).

But, the 640G blocks regardless of this issue. Currently I am using the 6mm version, as I do not carry a lot of body fat and need the 9mm.

So, I am going to report this issue to the authorities and will see what transpires. I see from other correspondents both on this and on other fora that this problem is not uncommon.

While the Minimed 640G is pretty, and a tiny bit smaller than the 722, I think it may have a design or configuration problem because the 722 just doesn't have the same issues (for me, at least).

 

[IanRA]

I believe I have solved this issue. Please refer to the attached. It shows how to avoid catheter folding and blocking.

 

[rockape37]

Just a tbought, is it possible that the inserter be the problem? Might be worth using a new one.

Regards

Martin

 

[IanRA]

Just a tbought, is it possible that the inserter be the problem? Might be worth using a new one.

Regards

Martin

Martin, the Mio is an automated device, so no inserter is needed as the inserter is part of the set. But I do believe I have solved the mystery for me, at least. Since resuming the Silhouette have had no issues. And thanks also to the excellent response team at Medtronics and my Diabetic Educator who worked in tandem to help. I am now once again using the 640G and the 722 has been retired to the cupboard as my reserve pump. Apart from the issue of Mio allowing assymetric entry as explained earlier, I have come to the conclusion I may not be anatomically suited to the straight entry catheter.

 

[rockape37]

Ah! I think these are what came with my pump but my nurse didn't give them to me. I'm using the cheaper ones Quick - Set Paradigm.

Regards
Martin

 

[IanRA]

Hi. Today I have changed my cannula / set about 5 times so just wondering if anyone has had a similar issue / could suggest anything. I'll start at the beginning...

My first 2 Cannulas failed today and when I took them out they were bent. This may have been a site issue due to scarring as I was using my love handles which I've been using for a while.

So I changed my cannula for a 3rd and 4th time relocating to my stomach which I haven't used much in the last 9 months due to being pregnant. Pump told me again that it was blocked.

Each of the error messages have occurred when I have bolused for food. During just having my basals my pump hadn't sent me any error messages and my sugar had been ok today - not stupidly high like I would expect if I had not got any basal insulin.

Phoned Medtronic for help and spoke to someone in America who ran some 'tests' eg asking me to put some insulin through the tubing and see if it comes out etc, which it did. Basically told me to see the doctor to get my sites checked and that was pretty much it.

Luckily managed to contact my DSN so will be going to see her tomorrow but any advice / experiences are welcomed!

 

[IanRA]

I have had several, and quite serious highs as a result of the Minimed MIO infusion set failing to properly insert the canula under the skin. You cannot detect this issue visually because the canula though bent and lying on top of the skin, instead of beneath it, is obscured by the adhesive disk that keeps the cannula in place. I am aware that if you do not properly align the plastic spring when loading, so that each side is evenly retained, this can cause the issue. But because I am hyper aware of that issue, the only thing I can think of is, as an older diabetic, the needle is not entering at 90 degrees, but is being deflected, maybe by a tougher skin, and thus the problem occurs. I have a very profound view that the Minimed Mio is NOT a safe device and should be withdrawn. In speaking to my diabetic community and endocrinologist, I have found this issue is not uncommon and has been reported several times to Medtronics by both DNE's and Endocrinologists. As a T1, ketoacidosis, which set failure causes, is not good. I am changing to the Silhouette, it is hand entered, so any failure to insert properly is immediately evident. I am likely to retire my current 640G in the next six months, any advice about other pumps and sets appreciated.