[Previous Months][Date Index][Thread Index][Join - Register][Login]
[Message Prev][Message Next][Thread Prev][Thread Next]

Re: [IP] Air in infusion tube...

Joanne, Your nurse is not quite correct.  1 Unit occupies about 2.5 in of
the current pump tubing.  So even an eighth inch of bubble is only a little
bit more than 0.1 U.  Thats why you neednt' worry about the small bubbles
in the tubing.

John, while it is true that higher pressure will eventually dissolve more
air in the insulin, this is a very slow process.   Much too slow to be of
any consequence during the time it takes to fill the syringe.  Sucking on
the bottle without injecting air is much worse, because it actually causes
new bubbles to form.  I find that injecting an amount of air a wee bit less
than the insulin I will withdraw generates no new bubbles.  Your 2nd needle
trick will also work, but that's just another thing to do, that I find is
not really necessary.   If a tiny bubble is so stuck to the syringe that my
snapped fingernail won't release it, I figure that both it and I are happy
to leave it stuck.
- -wm

<<<<<<<<From: Joanne Spotten <email @ redacted>
     I can see you have had lots of response on getting rid
of the bubbles.  I seem to always have a bubble in the
cartridge no matter how hard I try to get rid of them
so I watch for bubbles in the tubing.  The Nurse
Practitioner told me to always check the tubing for
bubbles as part of my twice a day 1 minute pump check,
even if I couldn't see any bubbles in the cartridge.
She also told me that 1 inch of bubble is about 1 unit
and I could disconnect (using Tenders) and bolus the
bubble out when it got close to the site or calculate
a larger bolus based on the size of the bubble when a
bubble was going to be included in a meal bolus.

<<<<<<<From: John Neale <email @ redacted>
If you inject air into the bottle before you withdraw the insulin, you
are pressurising the air in the bottle, forcing more of it to dissolve
in the insulin. Once it's in the cartridge, it then comes back out of
solution, and the next gets into the tubing...

If you don't inject the air, you have terrible trouble getting the
insulin out of the bottle, and you can end up with air bubbles leaking
in from behind the rubber seals on the piston...

So what to do? These last few weeks, I've been sticking a 2nd bare
needle into the bottle, so as I draw insulin out, air gently bubbles
back into the bottle at the same time. Pressure is maintained. No air in
the cartridge.


- -Wayne 

Insulin-Pumpers website http://www.bizsystems.com/Diabetes/