In mid-July, another fatal heparin error occurred in a neonatal intensive care unit (NICU). As many as 17 infants in a Texas hospital NICU were administered overdoses of heparin. Two of these infants have since died, although their deaths have not been definitively linked to the heparin overdoses.1 Hospital press releases reported that these errors were set in motion during the mixing process in the pharmacy, resulting in solutions that contained 100 times the usual dose of heparin. The errors were discovered by nurses following unexpected abnormalities on routine blood tests. Treatment was immediately undertaken to counter the adverse effects of high doses of heparin.1

The error in Texas followed recent high-profile heparin errors in California and Indiana. Several causative factors have been identified, underscoring the risks related to neonatal heparin use. A year ago, in Los Angeles, 3 infants received 1000 times the usual dose of heparin in heparinized flush solutions. Vials containing 10,000 U/mL, instead of 10 U/mL, were selected by nurses after the higher concentration solutions were accidentally stocked in patient care areas by pharmacy technicians.2 Since vials containing 10,000 U/mL are not usually available in the NICU, the nurses apparently picked them up without noticing differences on the labels until after the products were used. Similar circumstances led to the heparin error that occurred in an Indiana NICU in September 2006. There, 6 infants were given 1000 times the neonatal dose, and 3 of the infants died. As in the California incident, a pharmacy technician had mistakenly stocked the unit's computerized drug cabinet with vials containing a heparin concentration usually used in adults. The labels on the 2 vials were different shades of blue and looked alike, although the heparin strengths are different. In Texas, the overdose was reportedly unrelated to labeling or packaging of the heparin product.

The manufacturer has since changed the labeling on vials containing different concentrations of heparin, and hospitals have instituted new policies to try to prevent these errors from occurring. Many have removed heparin from medication supply areas in the NICU altogether. Although many NICUs no longer use heparin to flush peripheral intravenous lines, heparin is still widely used to maintain patency of arterial and venous central catheters, including peripherally inserted central catheters. Pharmacies responsible for mixing these solutions for neonatal patients must find ways that make it not only difficult but impossible for heparin errors to occur.

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