I've been using the T:Slim for about 4 months now, and really like it, with the exception of the bubbles that appear when priming the tubing. I’m amazed at the amount of air that gets trapped in the luer-lock while priming the tubing. It appears that some of the air comes from the T:Slim reservoir, and some of it is trapped in the luer-lock when I twist it to my infusion set tubing. I tap the reservoir cartridge rather vigorously and try to extract as much air as possible when I’m filling the reservoir with the syringe. However, when I’m priming the tubing, I usually need about 40 units or more to dislodge all the air bubbles trapped in the luer-lock and get it go through the full length of the 43” tubing. Very wasteful, but I don’t know how else to get the air out of the tubing. I realize that air in the tubing shouldn’t be a problem, other than by delivering less insulin that requested and therefore causing challenges in managing my BG levels, still, I’m trying to avoid the bubbles. Also, I notice that usually 24 hours after loading a new cartridge, I’ll find a few small bubbles in the luer-lock that weren't there 24 hours earlier, which must have come from the cartridge. Does anyone have any suggestions on how to minimize or eliminate the bubbles when priming the tubing?
I have been tsliming for about a year now. Had a little trouble at first with bubbles but have found system that seems to work for me.
I let my insulin warm up for a few hours before starting a cartridge replacement cycle.
When you fill the syringe do it in slow motion. Inject air in the vial for the full amount you want with the vial cap up, so you are not bubbling air through the insulin. Then when you let the insulin enter the syringe go slow. I start to get the air out when I have a cc in syringe. If you gently tap and then push air out of syringe you can slowly fill and not get air in syringe. The more aggressively you tap the more bubbles you generate.
When you inject the insulin in the cartridge go very slowly. The less force the less foam. I place the tubing firmly in the pigtails before filling. I have a space I my "storage closet" where I do my fill. I stand the tslim up on one shelf so the pigtails is up and drape/hang the tubing over a box on the shelf above it so the tslim and the pigtails and tubing is held steady and stays upright. Then I inject the insulin slowly.
I do not bang/tap cartridge when priming - I just let it do its thing. I have very little issues with bubbles. When I was following the tap the cartridge routine I had lots of bubbles. Not sure but it seemed to generate them rather than to remove them.
I do occasionally get a single largish bubble in the leur lock, but the design keeps it there, if you do not break it up it will not propagate down the line and cause issues.
I'm very insulin sensitive so missing out on even a small amount of insulin can cause me issues with control.
Should add that you can breakup the bubble that appears later in the pigtail by aggressively flicking the hub, and that will make it go down the tubing. But if you let it be it will stay put and not effect delivery.
Also the only time I had that bubble go the line was when I did not have the leurlock connection tight and the bubbles were coming from the connection not the cartridge.
Don't use the T-Slim but have the exact same issues when I don't pull the insulin out of the fridge an hour or two prior to swapping out sets. If I let the insulin warm up to more or less room temperature (and it doesn't take long) no issues with air bubbles at all. If I forget and move forward with cold insulin, dealing with air bubbles then and again that evening when I go to bed.
Thanks to both of you for your suggestions. I'll use room-temp insulin next time, and go very slow and see what happens. I never thought to just leave the bubble in the luer lock, and it would stay there. I'll check that out next time too.