Avoiding airbubbles

I want to find out whether anyone has any tips on filling their reservoir to avoid airbubbles. I find I waste a lot of insulin getting air bubbles out - sometimes 100 units. I know to fill it when the insulin is at room temperature but it still has annoying bubbles.

Ask your trainer the easiest way to remove air bubbles. They should be able to show you in the doctors office too.

There are a lot of videos on this subject on YouTube. Google by the name of your pump.

Lots of tapping with the tubing end pointing up, prior to installing the reservoir. Then, as it “loads”, tap the side of the pump, again with the tubing end point up. Also, don’t draw up the insulin too quickly or you will introduced lots of tiny bubbles that will coalesce into a larger air bubble.

If all you have in your tubing are “champagne” bubbles, no need to be concerned. It takes about 3 inches of tubing to equal 1 U so small bubbles just aren’t important.

1 Like

I also hold my tubing slightly taut when filling the tubing with the pump at the bottom and the tubing held up above it and twang it like a harp string a couple of times. This tends to make bubbles left inside the reservoir in the pump release and rise. In sets that have a quick release (I use Sure Ts) I flick the connection to release air from it and then fill a tiny bit more insulin to push out the air.


1 Like

Give the vial time to warm up to room temperature. My trainer told me this on my first pump (Medtronic) and it definitely holds up. Cold insulin just seems to generate a lot of bubbles, like carbonation coming out of solution, when you draw it into the reservoir. Room temp doesn’t mean no bubbles, but I usually just get the one big one that I think is mainly the residual air in the needle of the reservoir connector. That one is usually easy to tap into position, then a little pressure on the plunger squirts it back into the vial, after which no bubbles to concern about. I used to go nuts trying to get out the teeny-tiny ones—as @Dave44 says, the “champagne bubbles”—but he’s right, they aren’t worth the effort in terms of their effect on delivery.

1 Like

Hmmm…the only time my daughter ever gets occlusion alarms on the tslim is when she’s not careful about those champagne bubbles.

1 Like

By “effect on delivery” I meant voids in the flow, not actual occlusions. But yes, different pumps react differently to be sure. I’ve always used Medtronics. They have their problems but one thing in their favor is the pump mechanism itself is rock solid. I’ve had maybe 2 occlusion events per year.


When I;m filling the reservoir, I pull back firmly for a very little moment…then I tap to get the bubbles to the top (holding the reservoir with the bottle on the top). When I’ve cleared that bubble, I then put gentle pressure on the pull mechanism until the reservoir is filled. Then I turn everything upside down, so that when I pull the bottle out, the pressure in the reservoir is facing down, so no bubbles can get it. Then I insert the tubing onto the reservoir, again with the reservoir facing down (in other words, the part where a needle goes in faces down.)

I’ve been pumping for 18 years, and I almost never get bubbles in the reservoir other than that one big bubble the first time I pull some insulin in, which easily clears.

1 Like

Thanks everyone. Basically I’m doing what has been described, I’ve also seen a number of YouTube videos on this.

The only difference is I’m using a pen syringe and not a vial. The thing with pen syringe is that it doesn’t need to be pressurised and I don’t know whether it’s true but I’ve always had in my head that I can’t push the insulin back in while pushing out the air bubble.

When the Medtronic rep and my diabetes educator showed me how to do it, clearing the air bubble is always into midair and not back into the insulin source. Hence that’s where i get a lot of wastage.

Can you get some vials of insulin for pump use? IF cost is an issue (sounds like you want to also use pens) ask your doc if they have free samples. I got free insulin for several years from my last endo. As much as I asked for. Any type–pens of fast and slow, Novolog, Humalog…

Interesting, I hadn’t heard of that technique before. My prescription includes a yearly box each of Fiasp and Lantus pens as backup in case of pump failures, but I know not all insurers allow that: you get vials or you get pens. Never occurred to me that if you just got pens, you could use them to fill your reservoirs and still have pens for times when you want one. But I would have thought using a sealed pen injector would eliminate bubbles?

I used the Snap pump when Asante was still in business and one of the things I liked about it was that the “reservoir” was simply the glass tube from a Humalog injector pen, which slotted right into the pump mechanism. The mechanism pierced the stopper for you and there was nowhere for air to enter the connection. No bubble tapping! Unfortunately it used an optical sensor of some kind for detecting occlusions that was wayyyyy too sensitive, and but that’s a whole 'nother story…

You should be able to get pens as a backup to a pump. A doctor’s Rx should be all that is required. We never had any trouble getting back-up insulin product via group insurance, prior to the few years out last endo gave us anything we asked for, out of his office.

Agreed, but with emphasis on “should.” In previous discussions of this question, people reported that their insurance didn’t allow it. Pens or vials, not both. Some insurance sucks: this is known.

My point was more about asking for both form factors of insulin, rather than assuming that one can’t get pens AND vials. Of course, I don’t know the intimate details of every plan out there! :slight_smile:

Seems to me, pens would be more expensive than vials. Also, I use Symlin, which is a pen. I carry one in my pocket all the time. I have another one that I am using in the fridge, in case I don’t have my pen with me. I’ve noticed that the one in my pocket eventually get an air bubble.

I think that because of temperature variations. It warms up in my pocket and expands. Some Symlin is pushed out. Then I go outside in the cold and it cools down, contracting. Air is drawn back in.

I’ve also that the bigger the bubble the more Symlin comes out after an injection when I pull the needle out of my skin. I think the bubble is getting compress when I push the plunger. Of course, it does expand again, pushing the Symlin out. With the needle in my skin, there is a small back pressure, so the bubble doesn’t expand back to it’s full size. When I pull out the needle, no more back pressure, the bubble finishes expanding, pushing a drop of Symlin out,

Haha I’m actually the other way around. I’ve been using the pen since diagnosed, never once as the vial option given to me so I never even thought about it. I don’t even know whether we have the vial option here or whether it’s any cheaper. The pen always made sense in terms of when I need to inject, I have it without the need to syringe it out. I just thought the pen was how everyone does it these days until I saw the YouTube videos on people filling the reservoir