Abstract
These medication errors have occurred in health care facilities at least once. They will happen again—perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs.
Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below.
Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site (www.ismp.org), by calling 800-FAIL-SAFE, or via e-mail at
DTaP-Tdap MIX-UPS in ISMP Medication Errors Reporting Program Now Involve Hundreds of Patients
The Institute for Safe Medication Practices Medication Errors Reporting Program (ISMP-MERP) database contains hundreds of cases of accidental mix-ups between adult and pediatric products used to immunize patients against diphtheria, tetanus, and pertussis (whooping cough). Several reports involve errors that affected numerous patients. In 1 report, 80 clinic patients were given the wrong vaccine. These mix-ups may be affecting thousands of patients, given that not all cases are reported to ISMP.
We first reported this problem in 2006 (Institute for Safe Medication Practices. Adacel [Tdap] and Daptacel [DTaP] confusion. ISMP Medication Safety Alert! August 24, 2006). The official names of the products are very similar although stated in a different order on the labels. One of them, diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), is sold under the brand names Daptacel and Tripedia (Sanofi Pasteur) and Infanrix (GlaxoSmithKline). This formulation is for active immunization of pediatric patients 6 weeks through 6 years of age. The other vaccine, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap), is sold under the names Boostrix (GlaxoSmithKline) and Adacel (Sanofi Pasteur) and is meant to be used as booster shots for older children, adolescents, and adults.
These products are easy to confuse due to their similar names and abbreviations. The upper-case letters in DTaP correspond with higher antigen quantity of the diphtheria and pertussis components, relative to Tdap and its lower-case letters. A larger amount of antigen is needed for initial immunization versus a booster shot. An adult who gets DTaP (higher amount of antigen) would not need to be revaccinated but would be more likely to have a sore arm at the vaccination site. An infant/child who got Tdap would have received a lesser amount of antigen and may not respond adequately. Most reported events have occurred in clinics and doctor offices where the vaccines were chosen from stock supplies or in hospital settings where the vaccines were mixed up and stocked in the wrong area of a refrigerated automated dispensing cabinet (ADC).
The advice we gave in 2006 about preventing this mix-up still stands. That is, share this article with professional colleagues who handle these products. Separate the pediatric and adult formulations in storage areas. Encourage prescribers to order the vaccines by brand name, not vaccine abbreviation. Consider including parents or caregivers by making them aware of the names of vaccines that are needed by writing them down beforehand or by handing the patient a printed sheet that also details the purpose of each vaccine. (The Centers for Disease Control and Prevention [CDC] requires that vaccine information statements [VIS], which include age requirements, be given to parents and patients before each vaccination [www.cdc.gov/vaccines/Pubs/vis/default.htm].) Then ask the parents or caregivers to assist with verification of the vaccine before it is administered.
One hospital reported a significant reduction in mix-ups by employing a “time out” procedure before dispensing and administering these vaccines. Each “time out” is conducted by at least 2 clinicians and is guided by a laminated card with pictures of the 2 different products for reference. Another option is to document the vaccine, including lot number, on the vaccine form/log just prior to administration (but do not document actual drug administration on the medication administration report [MAR] until after the vaccine has been given). Recognizing a major difference in lot number format from what is normally recorded could help in recognizing that the wrong product is in hand.
After receiving earlier reports about product mix-ups, Sanofi Pasteur changed the color of the labeling for Daptacel and added statements on the product carton's front label panels for both Adacel and Daptacel that advise which is for adolescent/adult use and which is for pediatric use. Likewise, GlaxoSmithKline has taken steps to differentiate Boostrix and Infanrix to help ensure that they are administered properly. Similar to Sanofi Pasteur, they also label prefilled syringes and use vial caps with a unique color to differentiate each of its vaccines, and they have a statement on the packaging for Boostrix that the product is for adolescent and adult use.
Although these improvements may have helped to some extent, we are still receiving frequent reports of mix-ups. We believe more should be done to enhance vial label text to designate which is the pediatric versus adult vaccine.
We also think the abbreviations Tdap and DTaP are a big part of the problem, as is listing the nonproprietary name above the brand name on biologicals. This practice, which is inconsistent with the Center for Drug Evaluation and Research (CDER) drugs, decreases recognition of brand names, which are very different in this case. This is a significant cause of medication errors with multi-ingredient vaccines. Efforts are needed to revise the Code of Federal Regulations (CFR). For example, if the words Adacel and Daptacel were prominently highlighted, we believe this would be helpful in preventing mix-ups between the 2 drugs. Our thoughts have been shared with the US Food and Drug Administration (FDA) and the CDC.
Postproduction Intravenous Admixture Checks Less Than Ideal
We are aware of 2 recent fatal errors that reached patients due to intravenous (IV) admixture errors that were not detected during the checking process. Checks performed after manual IV admixture preparation often involve the “syringe pullback” method, particularly if the checking pharmacist is not consistently available in the IV clean room. To check each ingredient added to a total parenteral nutrition (TPN) solution or chemotherapy bag, for example, the empty syringe used for each drug or electrolyte is left alongside the item with its plunger pulled back to the volume that was added.
Even though the “syringe pullback” checking process is standard in many hospitals, it is less than ideal because the check is made after preparation and is based on the preparer's memory of how much product was added to the bag. Proper placement of the syringe next to the used product can also be problematic, particularly if the checking area is small and/or crowded. Situations have occurred in which empty syringes were placed alongside the wrong drug vial or the plunger was drawn back to an incorrect volume. If checking pharmacists noticed inconsistencies, they have occasionally assumed them to be errors in matching the syringe with the correct vial or pulling back the plunger to the correct volume, not actual errors during the admixture process.
To avoid these situations, commercially available or outsourced premixed products should be utilized whenever possible. When pharmacy admixture is required, products with high-alert medications (eg, chemotherapy, TPN, electrolytes, neonatal/pediatric infusions) should undergo an independent check of the vials, prepared syringes, and container labels (drug and diluent) prior to it being added to the solution.
Given that IV production errors can result in serious medication errors, new IV robotic preparation systems and commercially available workflow management systems are highly welcomed technologies. These systems utilize robotics or barcode scanning with video technology or digital images to reduce the risk of error. Stored digital images in workflow management systems allow visibility of the actual drug and amount drawn into the syringe prior to addition to the IV bag. They can also be used in a way that lets pharmacists complete essential checks when outside of the IV admixture area or even from a remote location.
Air Embolism Risk with Pressurized Sprayers
Surgical staff should be aware that air or gas embolisms have occurred during or immediately after application of fibrin sealants (hemostatic drug or biological products) using air- or gas-pressurized sprayers. The FDA has identified cases that appear to be related to the use of spray devices inconsistent with the approved product labeling and instructions for use. Although rare, the reports describe air embolisms that were life threatening and include 1 fatality—a 22-year-old patient who died from an air embolism likely caused by the method of product administration. In some reports the device was used at a higher than recommended pressure or at a distance too close to the surface of the bleeding site. All manufacturers of US-licensed fibrin sealants (Evicel, Tisseel, and Artiss), which are human-derived, have updated the Warning and Precautions section of their product labels to emphasize the risk of air embolism and proper use of the product. Evicel and Tisseel are used as hemostats whereas Artiss is used for adhering autologous skin grafts in burn patients. Labeling of the spray devices and nonfibrin hemostatic or biological products also includes information on recommended pressures and distances. More information can be found at the following url: www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm218530.htm.
Acetaminophen Study Yields Worrisome Results
The July/August issue of the Annals of Pharmacotherapy contains a University of California Davis study on prescription and nonprescription acetaminophen use among Medi-Cal patients during a 1-year period from 2004 to 2005. Among the group, 769 consumers were potentially exposed to at least 16 g of acetaminophen for at least 1 day, and 2,664 were potentially exposed to at least 4 g a day for at least 100 days. Sixty-one patients with claims of 4 g per day or greater for more than 100 days had a diagnosis of primary liver or renal dysfunction, which the study team found to be alarming. The FDA is currently considering FDA Advisory Panel recommendations to reduce the acetaminophen total dose per 24 hours and to make the maximum single dose for adults no more than 650 mg.