At U.S. hospitals, a drug mix-up is just a few keystrokes away

Posted May 2, 2022, 7:14 am

Brett Kelman

Kaiser Health News

More than four years ago, Tennessee nurse RaDonda Vaught typed two
letters into a hospital’s computerized medication cabinet, selected the
wrong drug from the search results, and gave a patient a fatal dose.

Vaught was prosecuted this year in an extremely rare criminal trial for a medical mistake,
but the drug mix-up at the center of her case is anything but rare.
Computerized cabinets have become nearly ubiquitous in modern health
care, and the technological vulnerability that made Vaught’s error
possible persists in many U.S. hospitals.

Since Vaught’s arrest in 2019, there have been at least seven other
incidents of hospital staffers searching medication cabinets with three
or fewer letters and then administering or nearly administering the
wrong drug, according to a KHN review of reports provided by the Institute for Safe Medication Practices,
or ISMP. Hospitals are not required to report most drug mix-ups, so the
seven incidents are undoubtedly a small sampling of a much larger
total.

Safety advocates say errors like these could be prevented by
requiring nurses to type in at least five letters of a drug’s name when
searching hospital cabinets. The two biggest cabinet companies, Omnicell
and BD, agreed to update their machines in line with these
recommendations, but the only safeguard that has taken effect so far is
turned off by default.

“One letter, two letters, or three letters is just not enough,” said
Michael Cohen, the president emeritus of ISMP, a nonprofit that collects
error reports directly from medical professionals.

“For example, [if you type] M-E-T. Is that metronidazole? Or
metformin?” Cohen added. “One is an antibiotic. The other is a drug for
diabetes. That’s a pretty big mix-up. But when you see M-E-T on the
screen, it’s easy to select the wrong drug.”

A five-letter fix: Making it stick

Omnicell added a five-letter search with a software update in 2020.
But customers must opt in to the feature, so it is likely unused in many
hospitals. BD, which makes Pyxis cabinets, said it intends to make
five-letter searches standard on Pyxis machines through a software
update later this year — more than 2½ years after it first told safety
advocates the upgrade was coming.

That update will be felt in thousands of hospitals: It will be much
more difficult to withdraw the wrong drug from Pyxis cabinets but also
slightly more difficult to pull the right one. Nurses will need to
correctly spell perplexing drug names, sometimes in chaotic medical
emergencies.

Robert Wells, a Detroit emergency room nurse, said the hospital
system in which he works activated the safeguard on its Omnicell
cabinets about a year ago and now requires at least five letters. Wells
struggled to spell some drug names at first, but that challenge is
fading over time. “For me, it’s become a bigger hassle to pull drugs,
but I understand why they went there,” Wells said. “It seems inherently
safer.”

Computerized medication cabinets, also known as automated dispensing
cabinets, are the way almost every U.S. hospital manages, tracks, and
distributes dozens to hundreds of drugs. Pyxis and Omnicell account for
almost all the cabinet industry, so once the Pyxis update is rolled out
later this year, a five-letter search feature should be within reach of
most hospitals in the nation. The feature may not be available on older
cabinets that are not compatible with new software or if hospitals don’t
regularly update their cabinet software.

Hospital medication cabinets are primarily accessed by nurses, who
can search them in two ways. One is by patient name, at which point the
cabinet presents a menu of available prescriptions to be filled or
renewed. In more urgent situations, nurses can search cabinets for a
specific drug, even if a prescription hasn’t been filed yet. With each
additional letter typed into the search bar, the cabinet refines the
search results, reducing the chance the user will select the wrong drug.

The seven drug mix-ups identified by KHN, each of which involved
hospital staff members who withdrew the wrong drug after typing in three
or fewer letters, were confidentially reported by front-line health
care workers to ISMP, which has crowdsourced error reports since the
1990s.

Cohen allowed KHN to review error reports after redacting information
that identified the hospitals involved. Those reports revealed mix-ups
of anesthetics, antibiotics, blood pressure medicine, hormones, muscle
relaxers, and a drug used to reverse the effects of sedatives.

In a 2019 mix-up, a patient had to be treated for bleeding after
being given ketorolac, a pain reliever that can cause blood thinning and
intestinal bleeding, instead of ketamine, a drug used in anesthesia. A
nurse withdrew the wrong drug from a cabinet after typing in just three
letters. The error would not have occurred if she had been required to
search with four.

In another error, reported mere weeks after Vaught’s arrest, a
hospital employee mixed up the same drugs as Vaught did — Versed, a
sedative, and vecuronium, a dangerous paralytic.

Cohen said ISMP research suggests requiring five letters will almost
entirely eliminate such errors because few cabinets contain two or more
drugs with the same first five letters.

Erin Sparnon, an expert on medical device failures at ECRI, a
nonprofit focused on improving health care, said that although many
hospital drug errors are unrelated to medication cabinets, a five-letter
search would lead to an “exponential increase in safety” when pulling
drugs from cabinets.

“The goal is to add as many layers of safety as possible,” Sparnon
said. “I’ve seen it called the Swiss cheese model: You line up enough
pieces of cheese and eventually you can’t see a hole through it.”

And the five-letter search, she said, “is a darn good piece of cheese.”

Vaught, a former nurse at Vanderbilt University Medical Center in
Nashville, was arrested in 2019 and convicted of criminally negligent
homicide and gross neglect of an impaired adult during a controversial
trial in March. She could serve as much as eight years in prison.
Her sentencing May 13 is expected to draw hundreds of protesters who
feel her medical error should not have been prosecuted as a crime.

At trial, prosecutors argued Vaught made numerous mistakes and
overlooked obvious warning signs while administering vecuronium instead
of Versed. But Vaught’s first and foundational error, which made all
other errors possible, was inadvertently withdrawing the vecuronium from
a cabinet after typing just V-E. If the cabinet had required three
letters, Vaught probably would not have pulled the wrong drug.

“Ultimately, I can’t change what happened,” Vaught said, describing
the mix-up to investigators in a recorded interview that was played at
her trial. “The best I can hope for is that something will come of this
so a mistake like that can’t be made again.”

After the details of Vaught’s case became public, ISMP renewed its
calls for safer searches and then held “multiple calls” with BD and
Omnicell, Cohen said. ISMP said that, within a year, both companies confirmed plans to tweak their cabinets based on its guidance.

BD raised the default on Pyxis cabinets to a three-letter minimum in
2019 and intends to raise it to five in a software update expected “by
the end of summer,” spokesperson Trey Hollern said. Cabinet owners will
be able to turn off this feature because it’s “ultimately up to the
health care system to configure safety settings,” Hollern said.

Omnicell added a “recommended” five-letter search through a software
update in 2020 but left the feature deactivated, so its cabinets allow searches with a single letter by default, according to a company news release.

Perilous typos: M-o-r-f-i-n-e

At least some hospitals must have activated the Omnicell safety
feature because they’ve begun to alert ISMP to workflow problems —
spelling errors or typos — made worse by requiring more letters.
Omnicell declined to comment for this story.

Ballad Health, a chain of 21 hospitals in Tennessee and Virginia,
activated the five-letter search while installing new Omnicell cabinets
this year.

CEO Alan Levine said it was an easy choice to engage the safety
feature after the Vaught case but that the transition has laid bare an
unflattering truth: Lots of people, even highly trained professionals,
are bad spellers. “We have people that try to spell morphine as
M-O-R-F-I-N-E,” Levine said.

Ballad Health officials said one of the most common issues arose in
emergency rooms and operating rooms where patients need tranexamic acid,
a drug used to promote blood clotting. So many nurses were delayed at
cabinets by misspelling the drug by adding an S or a Z that Ballad
posted reminders of the proper spelling.

Even so, Levine said Ballad would not deactivate the five-letter
search. Because of the pandemic and widespread staffing shortages,
nurses are “stretched” and more likely to make a mistake, so the feature
is needed more than ever, he said.

“I think, given what happened to the nurse at Vanderbilt, a lot of
[nurses] have a better appreciation of why we are doing it,” Levine
said. “Because we’re trying to protect them as we are the patient.”

Some nurses remain unconvinced.

Michelle Lehner, a nurse at a suburban Atlanta hospital that
activated the five-letter search last year, said she believed hospitals
would be better served by isolating dangerous medications like
vecuronium, instead of complicating the search for all other drugs.
Five-letter search, while well-intentioned, might slow nurses down so
much that it causes more harm than good, she said.

As an example, Lehner said that about three months ago, she went to
retrieve an anti-inflammatory drug, Solu-Medrol, from a cabinet with the
safety feature. Lehner typed in the first five letters of the drug name
but…