The two bottles were side by side in the refrigerator. One was twice as big as the other. But by mistake, Pharmacist Susan E. Kron apparently pulled out the morphine instead of the heparin.
For three babies in the critical care nursery at Anne Arundel Medical Center, that was the difference between getting the blood-thinning drug that helped to keep their intravenous lines open, and a painkiller that slowed their breathing.
Hospital officials say besides experiencing difficulty breathing, none of the babies was harmed. But the mistake at the hospital is an example of a national problem that experts say kills one hospitalized American every day.
The causes are simple. A doctor's illegible handwriting is misread, an abbreviation is misinterpreted, two similarly named or packaged drugs are confused. Unclear dosage directions can result in too little, too late, or a dose that's too strong. Sometimes a concentrated drug is used in place of a diluted dose.
The results can be tragic. Five years ago in Philadelphia, three infants in the neonatal intensive care unit at Albert Einstein Medical Center died because the pharmacist and pharmacy technician mistakenly added potassium to heparin, the blood thinner. The potassium caused a drop in the babies' heart rates, and they died.
"It's a major problem in hospitals," said Michael Donio, director of projects for People's Medical Society, the country's largest consumer health advocacy organization. In every 100 doses of medication, one error occurs, statistics show. Mr. Donio's group has put together a pamphlet that urges patients to carefully watch the drugs they are given.
In the case of children and infants, that's not possible, and parents can't always be around. And only recently has the U.S. Food and Drug Administration begun to push pharmaceutical manufacturers to define doses for children with their product's labeling information.
Heparin has been a magnet for medication errors in children. That's because drug manufacturers don't make a heparin flush -- a solution injected into the IV to keep the blood vessel from closing -- in the safest dose for children. So pharmacists, and sometimes nurses, must mix the heparin and its diluent themselves, said Michael Cohen, a hospital pharmacist with 25 years' experience and president of the Institute for Safe Medication Practices, which has tracked medication errors for the past 20 years.
"It's like anything else, if you have to make something," Mr. Cohen said, "there's always going to be room for error."
Manufacturers don't make the heparin flush because they have a difficult time making it accurate, Mr. Cohen said.
Still, only a handful of drugs -- including heparin, cancer drugs and opiates -- cause most of the medication errors. Mr. Cohen's group educates health professionals, and continues to push for drug companies to make the names, labels and packaging of drugs more distinct.
But with studies that show medication error the second most prevalent and expensive of all malpractice claims, other groups also are working for change. The American Society of Hospital Pharmacists is pushing for a multidisciplinary approach.
State and federal regulations govern hospital pharmacies, mandating certain standards that must be met in terms of dispensing medication. But hospitals decide what specific steps they'll take to meet the standard, so practices vary. According to experts, many hospitals have a second pharmacy staffer double-check the drug, its labeling, the container it came from and other areas.
That was not the case at Anne Arundel Medical Center's pharmacy, said Charles Tregoe, chief of the state's Drug Control Program, who examined the pharmacy this week. Now, the hospital plans to keep opiates in separate refrigerators in their sealed packs.
And with medium-sized hospital pharmacies dispensing up to 5 million doses of medicine a year, mistakes happen.
"We believe this was an isolated incident, and it fits in the category of 'stuff happens,' " said Carol Benner, director of the state's Office of Licensing and Certification Programs. Yet Ms. Benner said the incident was serious. And this case, like many others, won't easily be forgotten.
"It was tragic," said Mr. Cohen of the Philadelphia case. He can remember every detail. "Everyone who was involved was just devastated. Nothing could be worse than hurting a patient."