Hi all:

I am running into a problem with my pump. On the first day after a set change, BS responds to boli as I would expect. Day two, not bad but not as crisp as day one. Day three, I have to give more insulin to effect a given change in BS levels. My question is: is the insulin becoming weak because of exposure to heat or is the site not absorbing well on the 3rd day? I am leaning towards the temp answer as it doesn't seem to matter where I place the set or how long the cannula. By the third day it's fading.

I don't sit in the sauna or the hot tub, but I do wear a vest when awake which covers the pump and keeps it close to body temps. A night, I sleep under an electric blankie. The pump is probably pretty toasted by that. I seek opinions and wonder if anyone has used an evaporating pouch daily for an extended time?

My instinct says that you need to change your sets every 2 days. or find a different set. I doubt the insulin is getting so warm that it is losing potency on the 3rd day.

Did you always have this problem?

Can you wear your pump outside your clothes and turn off or lower the electric blanket for a weekend and see if it makes a difference?

I don't see any reason why you couldn't wear a Frio Pump Case all the time, but it is very bulky and might not be comfortable.

Linda B.

X2-

I don't think that heat is your problem. We have a member who wears a tactical vest over her pump in her law enforcement career, in Florida heat. No problem. Heat high enough from your electric blanket to cook the insulin into uselessness would also cook your skin. My bet is on the infusion sets being plugged with immune system reactions and reducing insulin flow.

I have had this problem for years, my body just starts rejecting the infusion site
and on day three I usaly make small corrections all day-- but it's not a big problem
for me I use a CGM. Also I have tried changing out my insulin every two days and it
did not correct my problem, it is defiantly my infusion sites.

Try changing your set every 48 hours without reloading the resavoir and see if this helps.

--><div class='quotetop'>QUOTE(Linda B @ Jan 10 2011, 11:48 AM) </div><div class='quotemain'><!--quotec-->Did you always have this problem?

Linda B.[/quote]


I don't know if I have always had this problem. When first starting the pump a few months back, a great many things were up in the air at the same time and noticing something as subtle as this issue is not something I would have been aware of.

I will take the various testing suggestions to heart. I wear sweats almost exclusively in the daytime but clip to the outside of the waistband. It will be quite easy to clip the pump to the vest pocket for a cycle. I mainly wear the vest so I have some pockets for the meter and the pump when a bathroom run is needed. If something as heavy as the meter is put in the sweats pocket, the pants head for the floor fairly soon. As for the blankie, I sleep cold enough that the power is on even in the summer and I designed an inverter system for my travel trailer so that even camping I have powered blankies. Turning it off means a nite without sleep. My tubing is 23" which leaves little room for putting the pump outside the blankie. Tucking the pump on the outside of the mattress won't help as it is a waterbed that is also heated. So the pump is heated whether on top or bottom. I'll think of something. As for changing the sets more often, that's easy enough to do... but getting more sets to do this on a long term basis will require some dancing.

Really.... the body plugs the cannula up? Wouldn't this set off an alarm on the pump?

You shouldn't have any trouble getting enough sets to change every 2 days - just have your doctor write the appropriate prescription if needed. Most prescriptions for pump supplies are written vaguely enough that you can order whatever you need.

The pump will not alarm if the insulin is being delivered but not absorbed by your body properly. In order for the pump to alarm it has to be totally blocked which is very different from not being absorbed.

Linda B.

I concur with what other members have posted. I wear my pump on or under my ballistic vest on a regular basis and as warm as it gets here (115 in the summer) I've never had a problem with the heat degrading my insulin. But... if you are worried about it, why not get a FRIO insulin pump case. I have one and also carry my spare insulin bottle in a FRIO wallet.

http://www.frious.com/

I have the same 3rd day infusion set issue as JohnG. When I remember, I increase my basals and boluses by 10% on the 3rd day. Otherwise, I find myself doing small correction boluses on the 3rd day, especially toward the end of the day. ( I also use a CGMS.)

Marty

OK, I am getting organized to try a couple of experiments. I gotta get some repeatable events so I can accurately measure the differences. BTW, When I was still doing MDI, I would leave the Novolog unrefrigerated on the counter (room temp) in the day times. By the end of the month the Novolog seemed to be getting weaker. That could not have been a site problem as the injections were in lots of different places. I did refrigerate at night.

I take a new bottle out of the fridge the day before using it for the first time and never return
it to the fridge...I carry the bottle with me any time I leave the house along with a syringe just
for backup in case something goes wrong...I live in Texas and it's very hot during the summer.
Novolog® is very heat resistant and is approved for 6 days in the pump resavoir. I have checked
the insulin temperature when the resavoir is inside the pump...the temperature runs from about
90F-96F all the time... the pump has a motor and electronics that create heat inside the case, the
resavoir is exposed to this heat before it is dissipated through the pump case.

Technically, Novolog is approved for 6 days in a pump at 86F (30C) or lower. However, Novolog, in the vial, is approved at the same temperature for 28 days so I assume that this is not an issue.

In any case, higher temperatures just increase the rate of decay of the insulin. It has to get pretty hot to have significant potency loss in 3 days.

I have found that my Apidra insulin just does this on day three. I dont think heat is a problem.