Running the reservoir down to zero

So, hypothetically has anyone ever run the reservoir down past zero?

Due to a comedy of errors yesterday, we did, and I'm trying to figure out exactly how much wiggle room there is and what happens when the pump registers zero units left in the reservoir. Here's what I can piece together:

10:30 a.m. Low Reservoir alarm (set to alarm at 20 units left)
4:30 p.m. Low Reservoir alarm (set to alarm again at 10 units left (or maybe that's a factory setting???))

Those are the only two things that show up in the alarm history.

At 11:00 p.m., the CGM alarmed. High SG, and two arrows up on the CGM. At that point, I remember my dad telling me around 5:30 p.m. that Jack had gotten a Low Reservoir alarm earlier, but I wasn't too worried about it, as I assumed it was the first alarm. So I check the status screen to see how many units he had left. Zero at 7:00 p.m. Holy youknowwhat!

So I give a massive correction and a temp basal increase. Because it actually wasn't that hard to bring him down, and he never really got above 250, he must not have actually been without insulin for very long. So my question is twofold:

1. Is there an alarm when the pump registers zero units left in the reservoir? It does not appear that there is, and if not, why the hell not?!

2. It appears that there is a "reserve" of insulin that is still there even after the pump shows zero units left. If he truly didn't get insulin from 7pm to 11pm, he would have been HI with ketones, and it would have taken him forever to come down. I'd guess that he probably was only without insulin for an hour or so. Does anyone know how big that "reserve" of insulin is? (I'd probably guess 5 units???)

I'm just glad I remembered to check the reservoir. Otherwise, I think I would have been correcting and correcting and not knowing why it wasn't working. It could have been a real mess!

 

Could it have been that he got the insulin that was left in the tubing and not the reservoir? We were told that there is probably a good 5 units in the tubing.

Don't know about the alarms, since we're pinging.

 

1. No. It's crap.

2. There definitely is. I've used about 10U past the point where the status screen says "--.--". (And verified that insulin is still coming out, by disconnecting and doing a fixed prime.) That being said, I don't think the "NO DELIVERY" alarm that eventually comes happens as soon as insulin stops being delivered, I think there is a small gap in time where no insulin is being delivered but there is no alarm. On the times that I've accidentally gone all the way up to the "NO DELIVERY" alarm, I have been high (trace ketones).

Eventually you would have got a no delivery alarm and realised the problem, but it is lucky that you checked the reservoir.

I'm trying to get better about my reservoir changing habits. I'm just ALWAYS busy at the moment that the reservoir runs out..

 

Thanks for the info, Emma.

That is ridiculous that there is no alarm at zero units! I admit that the two alarms before that should be enough, but when you've got a 7 year old who occasionally checks and clears his own alarms , it's not always enough!

I think there was still insulin in the tubing, but that there was a bubble there toward the end. I still can't quite believe I let this happen!

 

I'm slightly embarrassed that you can't believe you let this happen, and I let this happen, uhm.. every 3 days... But I guess that's the difference between dealing with D in yourself and in your child.

Yeah, I think there should be an emergency "you have ACTUALLY run out of insulin" alarm. Somehow it would bring a more rapid response.

 

This just happened to us this week - my dh is in charge in the summer since he is off and he thought I put too much insulin in the reservoir so when he went to do a site change he only put in what he thought my son would use - well of course he ended up alarming and running out of insulin at a very inconvenient time!

I think there is usually a circle on the pump screen - I can't remember if it is a closed or an open circle. It has never caused my son to have ketones but he has been high from it. Now that he manages himself more - this is one alarm he seems to always forget to let me know about!!!

 

Has anyone ever....? Oh, just wait till you have a teenager.

 

LOL. Yeah, I'm sure I would be much more blase about it if I was the one with D. Part of the problem too is that I work, and there are four different caregivers who might have him at any given time, and I'm really the only one keeping an eye on the "big picture." We have to have a cushion there, or it could all go kablooey in a hurry.

It's baffling to me that there isn't a "you have ACTUALLY run out of insulin alarm." But yet they have an annoying hourly temp basal alert that you can't shut off.

Ah, the circle on the pump screen. That's always on for us during the summer, as his basal is on Pattern A (during the school year, that's the weekend pattern). That stupid circle means so damn many things that it's virtually useless as an alert.

 

Yeah like Emma said, it gives you a no delivery when it's actually empty. I do this fairly regularly and I don't typically have crazy high numbers from it. There are a lot more bubbles at the very end of the reservoir, though. My best bet would be that a bubble got you guys.

Oh and I agree that there should be another alarm for zero units!

 

I tend to do this quite a bit..We are on the ping. It alarms at 10 units left and then again when it is empty. Zero units left.. IF I know that it is going to hit zero untis when we are at home and it is during the day I will let the pump go untill it hits that point. For the fact that I feel we are using all the insulin and not wasting any..If we are going to be away from home or I know it will hit zero in the night of course I replace it..I don't know if there is anything wrong with doing it..I surely hope that it does not damage the pump..Maybe I better research that..Now when the ping says it's empty, it's empty. There maybe insulin left in the tubing..Glad that you caught it before your son went to high.:cwds:

 

We have hannas pump set to alarm at 20u and also goes off when empty.

 

Animas 2020 alarms at zero and I push it close to that most of the time.

 

We've gone down to zero insulin and the Cozmo warns that it won't be able to give bolus', but the basal will continue for x hours. :cwds:

 

So does the Ping. It alarmed at 10u and I hit ok, bolused for dinner, forgot that we were due for a change, went off to track and it alarmed during practice. Oops. That was fine though as we usually unplug, especially when they do the longer runs.

I've found that since our insurance has changed and is not as generous as it once was, I tend to walk on the wild side more and let it run closer to 0.

 

Even if there is insulin left in the tubing, there is not "piston pressure" to get it into the body if the cartridge is rewound to the max. I always wondered if people in desperate moments could try to suck it up in a syringe or blow it out (not recommended I'm sure because of not knowing how much you'd get)

 

This happened to us one.. she cleared her own alarm, so when I saw it I thought it was the first one.. there is definitely a little extra in the reseveroir, use to drive me nut because it would say there were 10u/20u etc but clearly there was way more..I've primed it till it was empty, always have extra insulin in there.

I agree that there should definitely be an alarm for an empty reseveroir, like a solid beep or something, something annyoing so you actually check instead of just clearing it.

 

SO TRUE! We need this!

I think the zero line is on the Res. is when the pump says 0 - but yes, there is still that tiny tiny bit left in the top towards the cap.

 

This is a bad habit I got into when I had Minimed. (My last Medtronic pump was version 722). Anyway not only would I habitually run it past zero to get that last drop of insulin but I also learned how to only half clear a no delivery alarm so I'd occasionally end up going hours without insulin. That's the one where you clear the alarm but you don't follow through by hitting resume or rewind it'll let you sit in limbo forever. Very handy if you ran out of insulin in the car on the way home or in the middle of cooking dinner but not so good if you forgot about it and don't change out your reservoir or start it back up again. Hopefully they've changed this on the Revel. I don't know.

Anyway that is one thing that is different on the Animas pump once you hit zero you do have quite a bit of leftover but it won't let you use it. You have to change it out to shut the pump up.

To answer your original question there's at least 5 units if not more available after it reaches zero. I know I always got several hours worth anyway.

 

Same here. I'm proud that Abby knew she was alarming, knew to silence, but then "oopsies" I forgot to tell the nurse! So, we are definitely working on the oopsies part!

 

I used to run my MM pump well past "zero" - until I got a no delivery. It really did seem like there was almost always 8-10u still in there. I actually liked having that little bit of buffer past when it "said" it was empty. Funny thing is I ran into another pumper using a 523 last weekend and she says she usually does the same thing - changing the reservoir at a no delivery That's actually the one thing I miss the most about my MM pump, is that the reservoirs were so easy to change, and I could just carry a pre-filled backup with me.

My Ping stops delivery when it hits "zero" even though there is still a good 15u of insulin in the reservoir that could be usable. In a pinch I suppose you could pull the reservoir out of the pump and manually inject this through the tubing/site (without any kind of accuracy of course) but generally I try to change it whenever it's <10u just to avoid any kinds of situations where I desperately need insulin and my pump is empty... plus it's not as easy to just swap out the reservoir for more insulin like it is with MM.