Air bubbles in tubing

What do you do when you have large air bubbles in your tubing? Do you bolus them out or change your entire set?
If mine are only 2-3 inches long I play it out but have struggled for a while now with huge long air bubbles in tubing and wasting a lot of insulin changing out sets. Advice appreciated.
Hope you all had a very Merry Christmas, Happy New Year!

I bolus them out and also check that the connection between the tubing and cartridge is tight. If it happens repeatedly, I'd change the set.

There was a notice out recently that a lot of infusion sets are having issues breaking where the tubing meets the hub, which could let air into the system. I'd check and make sure you don't have one of those sets or lot numbers.

Well, that's irritating...and a control concern.

How is the air getting into the tubing? Do you have a crack in the luer-lock connection? Or is air getting around the o-ring in the insulin cartridge? What kind of pump do you use?

I use 42 inch long tubing and I think there's about 20 units in the tubing. It'd be less wasteful to prime the air bubble out than to replace the whole set.

My first question is where are the bubble coming from? The only way I can see them getting in is thru the reservoir filling process.

I don't mean to insult you by mentioning the basics but sometimes when problems occur it is caused by some mis-step in the basic process.

After you fill your reservoir how are you removing the air bubbles that form. I will always fill my reservoir to almost full then tap on the sides of it to force the air bubbles to consolidate at the top. I will then push up on the plunger forcing the bubbles up into to the vial from which I am filling. Then I slowly pull the plunger to complete the fill, if you pull on the plunger to hard when filling air can seep in around the seal causing bubbles. Once filling is complete it is important to closely inspect the reservoir to be sure no bubbles are missed.

I disconnect and prime to get the bubble out of my line. Ditto what Gary said above. But still, air bubbles happen sometimes, no need to ponder the reason. Do make sure you are getting all the air out of your res before you get the new infusion set going, you can click them to the top and push them out before you make the connection. Happy New Year back at you!

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I've never had a bubble bigger than say a millimeter over the past month of using a pump, and even that's fairly rare. I find that on my t:slim, those little bubbles, which only exit the pump as I begin the tube-filling process, collect in the Luer lock and then generally exit the tube before the insulin. Once I had a small bubble that stayed in the Luer lock, but since it seemed to stay there, I don't think it affected dosing, either. So I've never actually had to prime out a bubble, which has (pleasantly) surprised me. But I'm also neurotic about my filling technique.

You mention bubbles "only 2-3 inches long," that's got to be multiple units of insulin worth, and you're implying you get even bigger ones! There must be something wrong with your cartridge filling technique or elsewhere in your process. Can you be methodical about the steps in your process and where the issues might be?

Yes I've had bubbles in my line as long as 10 inches (almost entire tubing length). I have to change out sets at LEAST once a week due to this. I have even had a Medtronic rep come to my home and watch my changing infusion set method.
Each time I call Medtronic about the issue they seem dumbfounded.
I keep my insulin at room temperature for 28 days. I change my set every 3-4 days and wear the sure T infusion set.
I use Humalog insulin. I remove old set, rewind reservoir, pull back plunger too add air of 100 units then insert into Humalog vial turn upside down and slowly draw back 100 units of insulin into the vial. I tap multiple times and move plunger up and down to remove any bubbles larger than champagne size. I then connect to tubing and start set. When starting the set I always hold upwards that way any small champagne bubbles will go first. I never have any bubbles the first 24 hours but by day 2 I have multiple bubbles in reservoir, they start as large bubble at the bottom of my o ring so apparently there is air getting in some how and I absolutely cannot figure out how!?
Could it be the way I screw on the tubing to the vial? SO FRUSTRATING! Thank you all for replying and for attempting to help me solve this problem means so much to me!

That sounds bizarre, you're getting almost as much air as insulin in your reservoir somehow. It doesn't sound like your technique, the only thing I can imagine is that there's a reservoir/pump defect (and since this is happening consistently across reservoirs, it must be the pump itself) that is actually drawing air into the reservoir. It sounds to me like you need a new pump under warranty. If a Medtronic rep watches you and finds nothing to correct, and yet the problem still occurs, I think you need to put your foot down and insist on a warranty pump replacement.

I would recommend filling a cartridge at least a day in advance of when you need it. The moving of the plunger back and forth creates bubbles smaller than the eye can see. They need time to come back together as larger bubbles that you can then expel before placing the cartridge in the pump.

I will try this Mike.
Niccolo- This is my third pump with same issue :(

You might want to try using pen cartridges (if they are available in the States?) to fill your pump cartridges. I can't see bubbles and when I started pumping I did a ton of research about how people who are blind can pump successfully, and one tip I got was that the pen cartridges (the ones that go in refillable pens, not the disposable pens) generate way fewer air bubbles than vials. I've only used a vial once when the pharmacy ran out of cartridges, but from what I can remember it's ture. I also find I get fewer air bubble issues with Apidra than I did when I was using Humalog.

Also, when I first started pumping I had issues with huge air bubbles in the tubing even though I was filling the cartridge correctly. The pump trainer told me to screw on the tubing and then tighten it a bit a second time (but not too tight or it can crack) to make absolutely sure that it's screwed on. And she suggested (sounds weird, but I do it!) periodically smelling it to make sure the connection doesn't smell like insulin, which would indicate a leak where air could get in.

Hmmm, the odds of three defective pumps seem vanishingly slim. So it must be something about your technique. Bizarre that even having a rep there didn't help diagnose it. I wonder if the problem would follow you to a new brand/model of pump? Sounds really frustrating!

Pen cartridges seemed like a no-brainer to me when I started the pump recently, and I had a lot left over from my prior MDI time. My doctor and my rep both said filling with a pen cartridge was undesirable, but neither could explain why.

Why would non-disposable pens be better than disposable pens? It seems to me they function in the exact same way.

I've never used the disposable pens to fill a pump, but with the cartridges (for the non-disposable ones) you can withdraw from the cartridge without having it in the pen. There is no need to inject air because as you withdraw the stopper at the end of the cartridge will move - I think this is why it's not as prone to air bubbles, since no outside air is introduced. With the disposable pens, I may be wrong, but I'd think you'd have to inject air just as you would with a vial since the stopper and pen plunger wouldn't necessarily move as you withdraw insulin. For me personally, even if they both worked identically I would prefer the pen cartridges over disposable pens because the latter seems like unnecessary waste.

But why not use the pen mechanism to inject the insulin into the cartridge? Zero air involved, and I can’t come up with a downside.

Here in Canada the non-disposable pens are more common than the disposable ones, so that is what I get and what I have always used. I think in the U.S. the non-disposable cartridges are hard to get, though, so if the disposable pens also work with no bubbles, then that is great.

I’m just saying, why use a syringe at all, why not just use the pen mechanism to fill the reservoir?

I'm confused - why would you use a syringe? The pen cartridges are like little 3 mL vials. I just stick the needle screwed on to the pump cartridge into the pen cartridge and fill the pump cartridge directly. No need for a syringe or any other supplies.

My pump, the Tandem t:slim, has a cartridge that must be filled using a syringe. A pen seems like a good replacement for a syringe (is, in fact, a type of syringe) because there's no air bubble issue. Oddly, though, both my doctor and my Tandem rep advise against this, though not for any reason they can explain.

It sounds like you can mount a needle onto your pump cartridge, and then that cartridge can mechanically suck insulin into itself? That's just a fundamentally different design than I'm used to, hence the confusion.

Try to think of our pump cartridges as big fat syringes with removable needles. We attach the needle, draw up the insulin, then take the needle off and attach our tubing to the same place.