Early last Saturday, nurses at an Indianapolis hospital went to the drug cabinet in the newborn intensive care unit to get blood-thinner for several premature babies.
The nurses didn't realize a pharmacy technician had mistakenly stocked the cabinet with vials containing a dose 1,000 times stronger than what the babies were supposed to receive. And they apparently didn't notice that the label said "heparin," not "hep-lock," and that it was dark blue instead of baby blue.
Those mistakes led to the deaths of three infants. Three others also suffered overdoses but survived.
Now, their families, hospital officials and prosecutors are asking the same question: How could this happen?
Experts say last weekend's overdoses at Methodist Hospital illustrate that, despite national efforts to reduce drug errors, the system is still fragile and too often subject to human error.
"I see what happened here as depressingly normal," said Dr. Albert Wu of Johns Hopkins University, co-author of an Institute of Medicine report that estimated more than 1.5 million Americans a year are injured from medication errors in hospitals and nursing homes and as outpatients.
Methodist Hospital officials said they had safeguards in place before Saturday's overdoses.
Hep-lock -- a lesser dosage of heparin that is routinely used to keep intravenous lines open in premature babies -- arrives at the hospital in premeasured vials and is placed in a computerized drug cabinet by pharmacy technicians.
Nurses must enter their employee code and the patient's code into the cabinet's computer to open it. A drawer containing a large variety of medicines then opens, and they select the prescribed drugs from compartments and enter the amount withdrawn.
The system locks immediately afterward to prevent multiple withdrawals for the same patient. But there is no automated system to prevent nurses from taking the wrong medicine from the drawer in the first place.
According to hospital officials' account, a pharmacy technician had loaded the cabinet with heparin, at 10,000 units per milliliter, instead of hep-lock, at 10 units per milliliter.
D'myia Alexander Nelson and Emmery Miller died within hours of receiving the heparin. A little girl named Thursday Dawn Jeffers died late Tuesday. No autopsies were performed, but hospital officials said the cause of death was probably internal bleeding.
Even before the overdoses, the babies faced challenges. D'myia and Emmery both weighed about a pound and were born more than three months early, barely past the point where survival is possible. Thursday Dawn was three weeks premature and, by comparison, a robust 4 pounds, 6 ounces.
D'myia's grandmother Lena Nelson said the little girl had gained weight in her first four days, then died several hours after she was given the blood-thinner overdose.
"She was doing fantastic. I could see her growing right in front of my eyes," Nelson said. "Then she was taken from us."
Hospital officials adopted new safeguards to prevent a recurrence. Among them are procedures requiring a minimum of two nurses to verify any dose of blood thinner in the newborn and pediatric critical care units. Another system, using bar codes to track medications, was being developed before the overdoses and is still in the works.
Since 2004, the Food and Drug Administration has required that drug makers place supermarket-style bar codes on their drugs. Many hospitals have installed bar-code scanners to make sure medication matches the recipient and is given at the right time. But money is an issue for many -- the technology can cost millions.
Marion County Prosecutor Carl Brizzi said his office will investigate the deaths, but he is not assuming a crime occurred. The county coroner also is reviewing the case.
Methodist president and chief executive Sam Odle said the hospital planned no disciplinary action against those involved. "Whenever something like this happens, it is not an individual responsibility, it's an institutional responsibility," he said.
The five nurses and pharmacy technician involved are on leave and receiving support and counseling, and are expected to return to work, Odle said.
Nathaniel Lee, an attorney for the Jeffers and Miller families, said the drugs' maker needs to change how it labels heparin and hep-lock. Methodist has acknowledged two other heparin mix-ups involving babies in 2001, and said both infants recovered.
"If this was an isolated incident I would say that it would be solely the responsibility of the person at the hospital," Lee said. "But this is not an isolated incident."
Erin Gardiner, a spokeswoman for Deerfield, Ill.-based Baxter International, said the two drugs had different cap and label colors, bar codes and printing.
Wu, with Johns Hopkins, said the oversight was understandable, given that nurses were accustomed to having only the hep-lock vials stocked.
"If someone suddenly were to switch in your home where something was located, rearrange where your furniture was located, it would be really easy for you to trip and fall," he said.
The surviving babies face no remaining danger from the overdoses, Methodist spokesman Jon Mills said.
That is little consolation to Thursday Dawn's mother, Heather Jeffers, who blames the nurses, not drug labeling, for her daughter's death.
"I don't think it was from the label," she said. "They are both blue, but one is lighter than the other. How could they mistake those?"