Medication errors could lead to high variance rates

Study: Ready-to-use products cut admixture errors

Consider this scenario: Patients are dropping off your myocardial infarction pathway at an alarming rate, sending variances and treatment costs through the roof. And you don’t know why.

The problem could be medication errors, says Nancy R. Cirone, RN, MSN, director of nursing education at Bucks County Hospital in Warminster, PA. "Pathways can track patient outcomes, but that’s not necessarily going to track the medication errors," she says.

Cirone adds that just because a medication is listed on a pathway, that doesn’t mean the patient received it. "Remember, medication errors can result from omission of a drug as well," says Cirone. "And that would not be on the pathway unless you were actually using the pathway as a documentation tool. Case managers might not even know about the medication errors."

That can be a scary thought, given the results of a recent study indicating high rates of medication errors at American hospitals. The observational study of five regional U.S. hospitals found a 9% overall error rate in compounding of intravenous admixtures using the American Society of Health-System Pharmacists’ 1993 Technical Assistance Bulletin (TAB) on Quality Assurance for Pharmacy-Prepared Sterile Products as its guideline. However, the error rate for ready-to-use products was a scant 0.3%.

The 9% error rate was well above the 5% standard adopted in 1984 by the Health Care Financing Administration (HCFA) to determine certification for federal Medicare and Medicaid programs. And the study comes just as HCFA is publishing its findings and taking the first steps to lowering that standard to a 2% error rate. HCFA is expected to push the Joint Commission on Accreditation of Healthcare Organizations to adopt the 2% standard for private hospitals as well as long-term care nursing homes.

"We didn’t expect to find the rate of error to be that high," says the admixture study’s co-author, Kenneth Barker, PhD, head of the department of pharmacy care systems at Auburn (AL) University. "I think it’s reasonable to be alarmed and scared and concerned," Barker says of the results, published in the April 15 issue of the American Journal of Health-System Pharmacists.

Among the study’s findings is that two of every one hundred errors were deemed "potentially clinically important," based on HCFA’s significant medication error criteria for patient harm. Overall, 145 errors were found in 1,679 doses.

The study also sounds alarm bells for the handling of potassium chloride IV admixtures, where overall error rates ranged from 34.4% to 56.7% among both hospital technicians and pharmacists for that drug alone. The type of errors tracked included wrong-dose errors — the most common type found in the study — along with use of an unauthorized drug, wrong base solution, a product omission, or faulty preparation technique.

No. 1 cause of patient injuries, fatalities

With potassium chloride dosage errors topping the individual drug error category in Barker’s study, the drug’s importance for patient care cannot be outweighed by the care exercised in its usage, especially in the wake of the harmful and even fatal dosage errors being reported.

Everyone agrees with that assertion, but at issue is what hospitals are doing about it. "Potassium chloride error is the No. 1 cause of serious patient injuries and fatalities in the U.S.," says Stacy Wiegman, PharmD, a fellow at the nonprofit Institute for Safe Medication Practices in Warminster, PA.

"That 5% [HCFA] standard is bandied about a lot, but the answer is that a zero error rate is the only rate acceptable," says Wiegman. She points out that with potassium chloride, it’s not only the dosage amount, but the speed at which an IV including potassium chloride is given. "There are a lot of premixed bags, or hospitals make their own compound. The danger is that it can cause cardiac arrest when it’s infused too quickly," she says.

Wiegman says an infusion anywhere over 40 milliequivalents (mEq) per hour is dangerous. She also argues that ready-mades including potassium chlorides are not overly expensive for hospitals, and that many are using them. But the danger there, she says, comes when an order is sent that doesn’t comply with the premixed concentrations, say at 20 mEq, for example.

"We recommend that hospitals avoid special orders and develop a protocol saying you must prescribe a premade amount, and that has worked well at most hospitals doing it," Wiegman notes. She also recommends that hospitals do not add potassium chloride to an existing hanging bag, as the addition tends to pool around the infusion port, especially if the mixture is not vigorously shaken. Premixed bags again provide greater safety, she says. Also, while dosage protocols, premixing, and paperwork checks and balances help, the bottom line for safe handling is simply removing potassium chloride from the nursing floors, a move that is becoming imperative, she says.

That’s a step Cirone already has taken at Bucks County Hospital, where nurse education specialists and nurse clinicians have teamed to educate medical staff members about ways to avoid medication errors. Policies also are in place at Bucks regarding the use of ready-to-use products, and who is allowed to put potassium into an IV admixture.

The next step at Bucks County will require that the hospital’s 20 clinical pathways become a permanent part of the medical chart, Cirone says. "We’re seeing that many places are tying together pathways and the actual medications per day — what the patient should be getting, rather than just specifying classifications of drugs. But we’re not there yet."


1. Flynn EA, Pearson RE, Barker KN. Observational study of accuracy in compounding i.v. admixtures. Am J Health-Syst Pharm 1997; 54:904-912.

[Editor’s note: For more information, contact:

Kenneth Barker, PhD, department of pharmacy care systems, 128 Miller Hall, Auburn Univ., Auburn, AL 36849-5506. Telephone: (334) 844-5152. E-mail:

Stacy Wiegman, PharmD, Institute for Safe Medication Practices, 300 West Street Road, Warminster, PA 18974. Telephone: (215) 956-9181. World Wide Web:

Samuel Kidder, PharmD, MPH, Health Care Financing Administration, 7500 Security Blvd., Baltimore, MD 21244-1850. World Wide Web:

Nancy R. Cirone, RN, MSN, director of nursing education at Bucks County Hospital, Warminster, PA. Telephone: (215) 441-6629.]