I’ve been using the tslim since February. By far, my biggest frustration has been with the loading process and the bubbles that I’d continue to find in my tubing for the next three days. Tandem support told me to make sure that I was using room temp insulin and that I kept the pump upright, which I was already doing and didn’t really solve anything. After a lot of profanity, I’ve landed on the process below which has kept me pretty bubble free for the past three site changes. The bubbles that I am most concerned about are the big bubbles that can get caught in the luer lock - Tandem support told me that these big ones (bigger than a pinhead) HAVE to be broken up and moved out of the connector because they are affecting basal delivery at that size.
Ok, so here’s what I do:
- Get all the various things together.
- Put the needle on the syringe and stick it in the new cartridge (not yet installed). Pull plunger back until you feel resistance. Then remove syringe from cartridge, keeping pressure on the plunger to not allow air back in. I usually pull out about 50 units of air from the cartridge.
- Start the cartridge load process on pump. Remove old cartridge and install new one.
- Draw fresh insulin into syringe, removing air bubbles as you go and knocking with tooth brush to get rid of bubbles
- Stick syringe into old cartridge and pull plunger to get out the 50 units of leftover insulin in there (even though the pump said less than 20). Pull plunger until you feel resistance or until you start seeing air bubbles. Flick out any bubbles from syringe.
- Follow the rest of the load process as stated.
The only complication that I’ve noticed with this process is that, almost regardless of the amount of insulin that I load (usually 180-200 units), will register as 160 units. I learned at the beginning of my tslim journey to never trust the unit gauge, so I’m ok with that. The delivery mechanism is the part of the pump that actually measures anything, and I don’t believe I’m affecting that.
So that has helped restore my sanity and revive my love affair with the tslim a little. If anyone thinks I’m messing something up, I’d love to know! Happy to answer any questions, too.