Anyone going on a brand spanking new insulin pump is probably filled with anticipation and excitement, but there’s always a little bit of trepidation when it comes to a new piece of medical technology. Will it meet my needs? Will I like using it? Most importantly: will it work? The fear of potential problems like motor error, malfunctioning buttons, and occlusions can throw a wrench in anyone’s pumping anticipation.
Apparently, those wrenches have been flying around the Diabetes Community quite a bit lately, especially last summer when the newest insulin pump hit the market.
We have discovered dozens of new Tandem t:slim users who’ve taken to the Internet, reporting on blogs and social networks that their pumping honeymoon swiftly came to an end with the onslaught of occlusions using Sanofi’s Apidra insulin. Naturally we wondered what could be the cause, whether or not this was strictly a t:slim issue, and whether or not there is anything anyone can do about it.
Occlusions are basically just blockages that prevent insulin from being delivered. If you have a blockage, pressure will build and usually your insulin pump with alarm, letting you know something has run afoul.
« There are several reasons why they happen, » says Dr. Brian Levy, an endocrinologist and Senior Director of Clinical Affairs at Animas. « They include kinking of tubing that goes from the pump to the insertion side, or more importantly, the kinking of the catheter. Most cannulas are made of Teflon or plastic which can kink. It can also be due to problems at the insertion site, inflammation that can happen around the insertion catheter or the presence of scar tissue. If a patient uses the same place on their abdomen, there can be chronic build-up of scar tissue. »
Occlusions can and do happen in all insulin pumps, whether tubed or patch pumps, and they have happened with all three types of fast-acting insulin on the market.
But a 2008 research study published in the Journal of Diabetes Science and Technology showed Apidra had the highest probability of occlusions in pumps over five days (despite the FDA’s recommended site changes every 2-3 days). That was comparing Apidra to both Humalog and Novolog, although the probability of an « early occlusion » occurring during the first 72 hours was actually highest in Novolog.
In a 2010 study of the optimal usage of insulin pump sets, published in that same journal, researchers found that during the 48-72 hour mark occlusions occurred independently of the insulin used. However, that study only involved in 12 patients and the authors even note that occlusions are rare.
Apidra vs. t:slim?
The issue at hand is that after Tandem released the t:slim last summer, some new users started noticing something curious. Occlusions started occurring. A common theme: all the patients used Apidra.
Melissa Lee, a type 1 PWD in Texas, said that she started noticing the problem early on. « As early as my second cartridge, » she says.