Problems with infusion sets


(rdietrick) #1

Hello. My 16 year old just started on the Animas Vibe pump and Dexcom G5 CGM. He started with a straight inset 90 infusion set and just recently switched to the inset 30 because he’s so thin. When he switches out the infusion sets everything seems great - BG stays in the normal range and all is good for about 24 hours. Then his sugars spike and we have trouble getting them under control. Have even had to manual dose with a pen to correct a high that wasn’t coming down with the pump.

Has anyone else had problems like this? Maybe he’s not inserting the infusion sets correctly, but I would think if that was the case we would see highs right away, not after 24 hours. Since we’re so new to all of this I’m feeling a little frustrated by not knowing what to do. Any suggestions would be greatly appreciated! Thanks ~ Roberta


(angivan) #2

I had the same problem with the 90-degree sets and had to change to 30-degree, but have not had problems since. I have a Minimed, but I think the sets are comparable. Could he be tugging at the tubing that might cause the cannula to bend? Maybe it would help to put some adhesive near the beginning of the tubing to keep it stabilized. Also, I’ve found that I don’t need to go in at a full 30 degree angle…even just 15 degrees works fine as long as it’s definitely under the skin, which can be helpful if he’s really lean.

Ultimately you’re right that this should not be happening. Please contact Animas for support, and maybe they can set him up with a trainer to make sure he’s inserting properly.


(tored) #3

Sorry to hear you’re having problems using your infusion sets. Have you tried talking to your doctor or diabetes team? I have found thru experience that doctors are better and more informed when they’re with or thru a university. I found my doctor back in 1996 thru the local university here and have been with him since. I wouldn’t go anywhere else.

As far as your infusion set problem, it could be he’s not inserting the set correctly or he’s putting the 30 in too deep or too thin. You need to tell your doctor about it and that should give you the correct suggestions you need to use for that specific problem.


(davyboy) #4

Have you son look for large air bubbles, 1/8th inch or larger, in the insulin reservoir after the time he first begins to go high unexplainably. Go to discussion at http://t1n-migration.10uplabs.com/groups/medtronic_minimed_insulin_pump_users/forum/topic/airbubbles/#post-119167 for more information.

I learned that if I warm the bottle of insulin at the temperature of warm water (maybe 85 or 90 degrees) I get far less issues with air bubbles in the reservoir. Whenever I changed infusion sets it must be that the air was coming out of the insulin itself, due to not warming up the bottle before filling the new reservoir. Before this change, I would unexplainable rise above 400mg glucose level. Very hazardous to the body, generating ketones, which produces keto-acids in the body.


(tored) #5

I forgot to mention about bubbles in the reservoir as davyboy mentioned in the post above. I haven’t had highs as your son has, but I’ve had a problem with little bubbles also in the reservoir. I saw a video on Youtube about that same issue and the girl in the video mentioned that she talked on the phone with a Medtronic cust. rep and they told the girl in the video that to stick your reservoir on the insulin bottle and take out the gases (in the air) that build up inside the bottle of insulin. Here’s a link to the video - https://www.youtube.com/watch?v=OwbelFCNGz4. The Medtronic rep. said that gases build up inside the insulin bottle and will cause little bubbles to form in the reservoir when you draw insulin in it. So, take your reservoir and stick it on the insulin bottle and withdraw the empty air or gases in the insulin bottle. Do this for about 5 times. The girl in the video said to wait about 10 minutes before you put the insulin in the reservoir, but I don’t have that much time, so I just put the insulin in the reservoir immediately after I withdraw the air(gases) out of it about 5 times. I couldn’t believe it but it works. When I put insulin in the reservoir, sometimes I get an air bubble in there but I’m able to get it out of there quickly and end up with no air bubbles in the reservoir. Try it and see how it works and you shouldn’t have any more problems.


(davyboy) #6

I’m surprised you can get insulin into the reservoir with that much negative pressure in the bottle. But hey, if it works, great.


(zjohnnyr) #7
I’m surprised you can get insulin into the reservoir with that much negative pressure in the bottle.

I don’t think you are expected to also fill the reservoir while there is (a lot of) negative pressure in the vial. The idea as I understand is to reduce the ambient pressure in the vial to encourage the air dissolved in the insulin to precipitate (i.e. bubbles). That’s the idea behind the “wait about 10 minutes”.

I just put the insulin in the reservoir immediately after I withdraw the air(gases) out of it about 5 times.
And about how long does that take you? Remember that as soon as you lower the ambient pressure in the vial the air dissolved in the insulin will start to precipitate out. It does take time though. It sounds as though you are allowing time for it to precipitate by occupying your self with lower the air pressure in the vial.

(tored) #8

Sorry it took several days to answer back, I had a computer issue that took longer than I thought, but everything is fine now.

As far as the negative pressure in the bottle, there’s not enough negative air pressure in the bottle that I can’t even get the plunger back to withdraw insulin in the reservoir and just give up! I only withdrew air out the insulin bottle using the plunger 5 times using the plunger in the reservoir so the negative air pressure isn’t that great. It is more than what I started with and I have to exert more pressure on the plunger to withdraw it, but I played around with it and ended up with no bubbles in the reservoir. There’s not enough negative pressure that I can’t get any insulin in there. There are some bubbles initially in the reservoir, but they are alot easier to get rid of by just tapping the reservoir a couple of times and the bubbles go to the top of it and I just inject them back into the insulin. The bubbles are bigger and not alot of them in there. So, therefore, at the end of filling up the reservoir, there are no bubbles in there. Also, at the end of 3 days when I have to change my port, there are no bubbles in the insulin in the reservoir.

It sounds as if zjohnnyr is right as far as waiting after you’re done for 10 minutes to get the air out of the insulin into the air in the bottle, but I don’t have that much time to wait 10 minutes, so that’s probably why I’m getting a few bubbles in the insulin after I withdraw air out of the bottle 5 times immediately. I just tap the reservoir a couple times and the bubbles go out and I’m done. So far, it’s working, so I’m going to use it until I find something better. It’s alot better than when I had little champagne bubbles in there that I couldn’t get out.


(tedquick) #9

OK, but warming the insulin in the cartridge after loading works very well too. I always try to load the cartridge from the refrigerated vial some hours (or overnight) and put it in room temperature before putting it in the pump. Any bubbles remaining in the insulin will have separated out and can be seen and flushed out before connecting. Saves a LOT of trouble, I used to have highs at times before I started using this method.
Also, I have always used the Teflon cannula infusion sets made by Unomedical, which come with several different brand names, Tenders, Comforts or Silhoettes. The don’t pull out like the 90 degree sort that I used originally, the flexible cannula goes in at whatever slant I set it to, between 30 and 45 degrees. The tape attached to the base doesn’t cause irritation and stays on through the entire 3 day cycle.


(elizco4) #10

I have issues with angled sets. When I started the Vibe last year, I got both the Inset and Inset30, hoping the Inset30 would be good for my leg sites. No dice. I was constantly fighting highs with the Inset30. Now I only use the Inset and have awesome numbers. I know the Inset30s HAVE to be at a particular angle for the set to be inserted correctly. You don’t have to deal with that with the Inset. I wear my Insets in my abdomen and thighs.


(tedquick) #11

Sounds like the Inset 30 needs to be at a specific angle since the canula is longer than with the Inset. Presumably the longer needle wen into the muscle in your leg, which absorbs insulin MUCH faster plus it hurts. I never used either one myself, just used the Comfort/Tender/Silhouette version, which is the original design for the other 2, if I understand it. Main difference is that the base is round, where the Inset is more pointed, plus it comes in colors.

Ted Quick in Ohio


(davyboy) #12

I often have same problem. Somewhere else on this site a few of us have discussed getting large bubbles in the insulin reservoir. Check yours to see if you get them, several times a day, say each time you bolus for a meal. if there is a big bubble, you need to disconnect from the inset and pump the bubble up through the line. I theorized how the bubbles get in there, and I am still a bit stumped. I just know this, and I use Medtronic, the reservoirs are plastic which attracts tiny air bubbles to the inside surface of the reservoir, almost invisible to start with. The O-ring seals at the bottom of the reservoir on my pump are round cross-section but the area in which they are inserted are square cross section. I think that is problematic; I also notice that after a day, small bubbles collect along the inner surface of the O-ring that touches the insulin inside the reservoir.

I raised the issue extensively with Medtronic, but they keep ducking the issue by blaming it on me, nicely, or just not replying at all. So I filed complaint with FDA, who oversees the pump industry, and they included it in their system. I do not know what they did with it, but others have also filed similar complaints. I googled bubbles in insulin pumps and got many hits, particularly in Europe for some reason.

I think this problem is endemic in the plastic reservoirs. The round O-rings in square cutouts can’t be good, and is a terrible design. The rings should have square cross-section. Also the soft rubber makes it easier for the ring to distort and let air cross the boundary. There is also the problem of diffusion, which can allow a gas cross a boundary into a liquid under higher pressure. It goes against common sense, but is a well-explained phenomena in chemistry.

If you find the bubbbles I recommend reporting it on this site in the appropriate place (search for air bubbles) and complain to
Animus, and if they do nothing, complain to FDA. the problem needs to end.

Finally, make sure you don’t draw cold insulin into the reservoir when you fill it; bring it to room temp first. And make sure to tap out all air bubbles. As I pull the inner piston of the reservoir back, I also rotate it, which seems to bring up air bubbles. I do that just to make sure I am wetting all the surfaces.


(davyboy) #13

I tried that and it did not work, was worse than leaving air in the bottle. Reason is that you now have negative air pressure in the bottle, and it is harder to pull out with the reservoir plunger. Furthermore, it pulls air into the reservoir, in the form of tiny bubbles, from the air vent in the top of the reservoir. whoever gave that stupid advice obviously is not a diabetic having to live with such advice. that is inexcusable of Medtronic.


(tedquick) #14

OK, I agree you need to warm the insulin in the syringe before filling the hose. Another point is to only put a very small amount of insulin in the syringe, then pull the needle out and roll the syringe on it’s side to wet the O ring all the way around, rather than just puling the insulin in over the whole plunger/O ring at one, which will trap bubbles in the edges over the O ring. Then put it back into the vial and fill the rest up, following with tapping to release other bubbles.
Unfortunately the problem with the O ring seal is that if they make it a square cross section the resistance goes up, since there is more rubber contact area. This will likely upset the occlusion alarm sensing, and possibly use batteries up faster.


(Jess) #15

I deal with air bubbles by prefilling the reservoir, then I let it sit out at room-temp for a few hours. Then when I go to change the reservoir, I will fill the tube completely, then I have a little jig I made to clamp and hold the end of the infusion set above the pump, so the tubing is perfectly vertical and strait. This allows those little bubbles trapped at the top of the reservoir to slowly work themselves out of the end of the tube (you can watch them). After about 15 minutes, I come back, and flush a few more units of insulin out the end of the tube along with the air bubbles that have risen and accumulated near the top of the tube.

It’s kind-of a pain, but this is the system that I’ve found works best for me. My infusion sites get much less irritated when there are less air bubbles too.