Frugality : Update

In my last post, I talked about the possibility of maybe filling one of my pump’s insulin cartridges and simply changing my site mid-use. Doing this would save how much insulin I waste both in tubing and in that “cushion” of insulin that Tandem’s t:slim pump has since I’d only be throwing those out every 6 days verses every 3.

So, I started my experiment last week. I filled my cartridge up, hooked up, and hoped for the best.


After 3 days, I got the alert to change my site. By this time, I was down to 155u, so I was right on track for the mid-6 day site change-out.


Now, last night was the time when I get nervous because a) it was night time and b) I had 18u of insulin left. Looking at my pump though, I used only .9u per hour during the night, so I would have had enough to get through until morning. So, I got my little change-out bag together with my site, tubing, cartridge and filled the syringe and had it all ready to go.

I got to work and after bolusing for breakfast, my pump was down to 2u. By 10am, I looked and it said “1u”, but I knew it would alarm empty soon…


And then it did…


So. After 6.5 days, I was ready to change out again. Best part was, I didn’t have any decrease in glucose control throughout the whole process. Granted, once warmer days get here, I may need to go back to changing everything out every 3 days, but at least during the cooler months I know I can do this as an option.

(*read: do not take this as medical advice for yourself. this is simply stating what I have done and in no way implies you should do the same. always consult your health care professional before doing anything different from your current treatment plan.*)

Now, on to find an angled site I can use higher on my belly or on my love-handle area since this growing little baby is now starting to use my mid-section for a temporary home. 🙂

How It Works

I’m one who likes to take things apart and see how they work. I’ve done it with the Omnipod pods (both older and newer generation) and also the Asante Snap pump body. Granted, I haven’t done this with any other pump seeing as how they cost several thousands of dollars, but I am sure they are cool on the inside too.

Now, with the Tandem t:slim, I’ve been intrigued as to how the “micro-delivery” pump action works, since it’s different than other standard piston style pumps in that it doesn’t push from the bottom of the cartridge up, but rather a small bit is vacuumed into the mechanism to the bag and then pushed up into the tubing – a safety feature that allows you to only be subject to 0.3u of insulin at the time verses, say, 20-300u. So, true to form, I took a cartridge apart to see how it actually works. Granted, I’ve taken several apart just to see the bag on the inside, but never to actually see the mechanics of the pump itself. So, for those of you who are just as excited about this stuff as I am, here you go:

So, basically, there’s two little pieces at the end of the piston rod that when pushed in, push air or insulin into the tubing and the space between the two parts of the piston rod is eliminated. When the piston rod is pulled back, the space between the two parts fill with insulin as it is pulled apart and then the insulin is moved back into the area under the tubing to be pushed up into the tubing when the piston rod is pushed back again. It’s a rather genius idea. And the parts? They’re interlocked in a sort-of T pattern. How awesome? Now whether or not that is where they get the ” t: ” part in everything, I’m not sure, but I know that the one little piece looks very similar to the “T” button on the pump, which is just.freakin’.COOL… like, COOL doesn’t describe it… it’s WICKED AWESOMENESS.

Of course, if you want to see Tandem’s official video, you can go here.

I don’t know why this stuff excites me the way it does. To others, this may not be that cool and they’ll think I’m totally off my rocker, but this stuff, to me, is super awesome and gets me fired up. I like to know they how and why of things, not just that it is what it is. So, High-5, Tandem developer people. You’ve made this inner tech geek VERY happy. Of course, it would REALLY blow me away if I could see the inner workings of the pump, but you know.. I don’t want to ruin this $7k piece of life-saving beautifulness.

Could It Really Be?

*insert sound of messenger “ding” here…*
“Hey Sarah – I wanted to let you know, I’ve now used two of the cartridges you sent me and both times I’ve had extreme highs once I was down under about 120 u. I never had that experience on the box they send me with my initial order or with my 2nd shipment. So I’m guessing, even though the ones you sent weren’t in the recall, they are experiencing the same problem (no way to know for sure). I hope that this will at least make you feel better about the experience you had…”


Could it be? Like, seriously.. could this really be happening? Like… to the EXACT. SAME. CIRCUMSTANCE?!?

A feeling of overwhelming joy yet guilt rushed over me within two seconds. Joy that I wasn’t crazy after all in everything that I had been wracking my brain to try to figure out about the t:Slim cartridges that I had, while at the same time I felt guilty because my friend had experienced it and was now very high.

When the news of the Tandem Cartridge Recall had come out, I immediately checked my boxes. Since they had been in waaaaayyy earlier lot number sequence (like, in the 300’s), I didn’t think they could be it, so it had to be something else. But it was just too uncanny how similar her and my experiences were. The same thing.. the same problems – highs resulting from using the cartridges and getting to the last third of the cartridge.

After I received the message from my friend, I bounced around the idea of buying and paying out of pocket for a box of cartridges myself just to see (especially since insurance had just paid for 2 boxes of Medtronic cartridges, and they’d probably deny the claim anyway). If it didn’t work, that was just going to be $25 wasted. But if it did? That would be a hugely awesome thing.

While I know my specific lot numbers weren’t listed, they may have been too early to have even been tested (going on an assumption there). Either way, what ever they did to fix them seemed to fix that big issue I had. I’ve now gone through two cartridges and am happy to report that I did not have issues as I did before. I was able to use every bit of the insulin that it would let me (you know, minus the 40-50u of unusable insulin) down to where the pump read zero. This makes me extremely happy because I loved that pump so much and was absolutely heartbroken when I started having issues with it (can one really be heartbroken over a medical device? yep). Now I just have to figure out what I want to do.


 I do want to send out a big “thank you” to my friend for letting me know what she did, as well as Tandem for keeping me up to date about the cartridge recalls over time. It means a lot to me.