The New Jersey Department of Health and the Institute for Safe Medication Practices (ISMP) have each recently warned about several different ways that dangerous mix-ups can occur between insulin and heparin.
Some of these mix-ups happened when patients receiving total parenteral nutrition had insulin added to their TPN bags instead of heparin. In one case, a premature infant in the NICU had a blood glucose level of 17 mg/mL several hours after being started on a TPN infusion. Despite multiple administrations of dextrose, the hypoglycemia did not completely resolve until TPN was stopped. A later analysis showed that the fluid contained insulin, not heparin. This infant's long term outcome has not yet been determined, and ISMP describes two similar incidents where the babies died.
These kinds of errors can happen other ways. For example, two patients who were not diabetic died after being injected with insulin instead of heparin during a vascular catheter flush procedure. In a different case, a nurse erroneously transcribed a verbal order to resume an insulin drip as "resume heparin drip." And in yet another case, a pharmacist entered an order for heparin 500 units into the computer as "regular insulin 500 units."
ISMP says several factors contribute to these mix-ups. First, the 10 mL vials of insulin and heparin often look similar. Both insulin and heparin are typically used every day during each shift, so these similar-looking vials are often next to each other on a counter, a drug cart, or under a pharmacy IV admixture hood. Both drugs are dosed in units. And ISMP says that as insulin infusions become more common, the risk of a mix-up may be growing.
The New Jersey Department of Health and ISMP recommend a number of strategies to reduce the risk of these kinds of mix-ups. Here are some of them:
• Do not keep insulin and heparin vials next to each other.
• To avoid using vials that look alike, consider using heparin bags of 100 units/mL. Heparin prefilled syringes could be used for admixtures. And consider providing insulin to patient care units in pen devices rather than vials.
• Require independent double-checks of IV insulin and IV heparin doses and infusions, and also an independent double-check through each step of preparing TPN solutions.
• Write verbal orders directly on order forms and then verify the accuracy by reading back the order.
• Finally, when a patient develops unexpected, unexplained hypoglycemia, consider the possibility that a medication error may have occurred and take the following steps: discontinue all current infusions and hang new solutions, treat the patient as necessary with dextrose, and check for unintended additives by sending the infusion bag(s) for analysis.
Additional Information:
ISMP Medication Safety Alert! Action needed to prevent dangerous heparin-insulin confusion. May 3, 2007.
http://www.ismp.org/Newsletters/acutecare/articles/20070503.asp
Tags: Insulin Heparin Patient Safety FDA Diabetes
