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
What's Wrong with “Ketofol”?
The term “ketofol” is becoming commonplace in many hospitals and is used to describe a combination of ketamine (Ketalar) and propofol (Diprivan). The admixture is used for procedural sedation. The combination of these 2 drugs has been favored, because it is said to preserve sedative efficacy while minimizing each drug's respective adverse effects.1–4 The combination of drugs is believed to result in less toxicity than either drug alone, because the complementary effects of the drugs enable the use of lower doses of each drug. 4 A combination of these 2 drugs is not available commercially, so the drugs are mixed within a single syringe prior to administration.
Although studies have shown that ketofol appears to be effective and safe for procedural sedation before painful procedures, 4 a few important safety issues linger.
For efficiency, ketofol admixing often takes place in nonsterile areas such as procedural units and the emergency department. Since propofol has inherent sterility issues, close monitoring is needed to ensure that the admixture occurs under sterile conditions, that single-dose vials are not punctured multiple times, that the appropriate expiration date is applied to the syringe, and that the medication is properly discarded upon expiration.
Another problem with this drug combination is its name. “Ketofol” is a contrived name, so at least for now (and maybe never), you will not find the admixture listed in any official compendia or most commonly employed drug references. This, of course, may present problems for people unfamiliar with the contrived name. There is also a potential for drug mix-ups if ketofol is misread or misinterpreted to mean Ketalar alone.
There is also very little information available regarding the compatibility of these drugs with other drugs and solutions. Drug information resources only list Y-site compatibility for ketamine and propofol for up to 1 hour. 1 However, 2 recent studies have shown that this combination is stable as an admixture for at least 3 hours in 2 different concentrations (1:1 and 3:7).2,3
The concentrations and volumes of the 2 products used to mix ketofol are not standardized. Different ratios (percent of each drug in the syringe) have been employed. Therefore, ordering ketofol or labeling a syringe as ketofol at 1 institution (or on 1 unit) may indicate a 1:1 ratio of ketamine to propofol, whereas at another institution (another unit), “ketofol” may indicate a 1:4 ratio. A further problem with differing ratios is that the stability of any ratio other than 1:1 and 3:7 is not known.
Finally, a syringe containing ketofol looks very similar to a syringe containing only propofol. So, with ketofol, there is now a syringe containing “the other white stuff”—as an ISMP staff member overheard another health care practitioner say when referring to “ketofol.” We have received enough reports of mix-ups between other white substances—intravenous lipids, propofol, Rotaglide (a fat-based lubricant used during procedures)—to know that ketofol will likely add to the problem.
If you use a combination of ketamine and propofol for sedation, consider conducting a failure mode and effects analysis to identify risks, including those discussed above. Take steps to promote sterility during admixture, and establish a standard ratio to guide the mixing process. Although it will no doubt be an uphill battle, we recommend not using the term “ketofol.” Many hospitals appropriately require that each drug's official name be designated—such should be the case for a combined ketamine and propofol product. The syringe label should also include both product names and their doses.
Trace Elements Conundrum
With the continued shortage of many injectable products, a hospital ran out of its usual pediatric trace elements injection (Trace Elements Injection 4, USP-Pediatric) in 10 mL multiple-dose vials from American Regent. As a substitute they ordered the company's Multitrace-4 Pediatric in 3 mL single-dose vials. This product states on the label, “Trace Elements Injection 4, USP,” just like it states on the 10 mL vial. The pharmacists thought the only difference between this product and their usual pediatric trace elements solution was the smaller vial size and the fact that it was a single-dose vial. However, when the shipment arrived, the pharmacist checking the product determined that the formulations were different. Both products have the same elements, but the 3 mL vial has 0.5 mg more zinc and 5 mcg less manganese per mL.
When a pharmacist later questioned the company, he was told they have 2 different names to help differentiate the products, even though each label states “Trace Elements Injection 4, USP.” We learned from our colleagues at the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) about a conundrum brought about by the USP monograph on Trace Elements Injection. Although defining the contents and their sequence in labeling, the monograph does not state the product's individual quantitative amount of each element. Thus, it appears there can be an infinite number of different multitrace elements products of zinc, copper, manganese, and chromium, all of which can be labeled generically as “Trace Elements Injection 4, USP.”
This incident points out the problems that occur during times of heightened drug shortages, and how difficult it can be to find products to meet the needs of patients. When you obtain new products due to drug shortages, always check to be sure the products are what you anticipated, as the pharmacist did in this case.
PCN-200, Not Penicillin
A nutritional supplement called “PCN-200” may very well be among the options if someone types “PCN” into the computer system when entering patient allergies. PCN-200 was a grapefruit seed extract product that was discontinued by its manufacturer, Bio-Tech Pharmacal, several years ago. The problem is that it is still showing up when health care personnel attempt to enter a penicillin allergy in the computer system's allergy field by typing “PCN.” We mentioned this supplement in 2006 after a hospital contacted us to let us know that one of their nurses had typed “PCN” for a penicillin-allergic patient and inadvertently selected PCN-200. 5 Thus, alerts or reminders would not have appeared on the screen if a penicillin product had been prescribed and entered into the patient's drug profile. Last week we heard from another hospital that converted to an electronic health record this past year. They just realized that 33 patients had erroneously been coded as having a “grapefruit extract” allergy instead of a penicillin allergy. It is not known if any of these patients were actually given penicillin products as a result of this error. PCN-200 is no longer available, so why is it still showing up, especially when the drug information vendors we contacted this week tell us they haven't listed it since 2006? The short answer is that the problem is probably with the way the computer system vendor created and maintains the allergen “pick list.” In other words, some of the drugs or items originally included by the computer system vendor may never have been eliminated, even though they have been discontinued by the manufacturer and drug information vendors. If PCN-200 is still listed as an option (type “PCN” in your allergy pick list to find out), either remove it manually or work with your computer system vendor to remove it.