In a recent article, the Institute for Safe Medication Practices (ISMP) highlighted several potential safety problems when hospitals switch from multiple dose vials of insulin to insulin pens.

ISMP points out that there are certain safety advantages in using the pens. For example, the pens may reduce the chance of drug mix-ups, since each pen is pre-labeled with product name and strength, and the patient’s name can be on the label as well. But ISMP also notes a number of potential safety problems to watch out for when hospitals switch to pens.

One possible problem is needlestick injuries, which could happen because the pen may make it difficult to see the injection site. Also, some needles do not have needle guards, so a needlestick can occur after the injection.

Another difficulty is that part of the insulin in the pen may not be delivered. This can happen because the buttons on some pens are difficult to push down, making it easy to accidentally lift the needle out of the skin during the injection. There can also be leakage around the injection site if the needle is not left in place for at least six seconds after the injection. In addition, uneven dosing of an insulin suspension can occur if the user fails to tip and roll the pen before the injection, causing the suspension to clump.

Sometimes nurses unfamiliar with a particular type of pen will use it as a multiple-dose vial, withdrawing insulin from the pen cartridge with a sterile needle and a conventional insulin syringe. This is not recommended, because aspirating insulin from the cartridge can leave air pockets. When the cartridge is used again, these air pockets can cause dosing errors or air injection.

Another problem is using the same pen for multiple patients, which is potentially hazardous. Attaching a new sterile needle to the pen before using it on another patient cannot solve the problem. That’s because the insulin inside the pen’s cartridge can become contaminated with biological material after the first injection, while the original needle is still on the pen.

Finally, the design of some pens can lead to dosing errors. For example, in some cases the digital display of the dose can be mis-read if a person holds the pen upside down, as a left-hander might do. In that case, a dose of 21 units looks like 12.

How can these problems be avoided? ISMP says that the key is to prepare for the transition to pens. That means understanding and anticipating the risks beforehand, doing a failure mode and effects analysis, educating the staff about using the pens properly, and closely monitoring their use for the first few months of the transition. ISMP recommends that written guidelines be developed for each type of pen used in the hospital, with specific instructions on handling the pens safely, injection techniques, and prohibitions on sharing pens or using them as multiple dose vials.

Additional Information:

ISMP Medication Safety Alert. Considering Insulin Pens for Routine Hospital Use? Consider This…Volume 13, Issue 9. May 8, 2008.
http://www.ismp.org/Newsletters/acutecare/articles/20080508.asp