MADISON, Wis. – By most accounts, nurse Julie Thao helped hundreds of women giving birth during a 15-year career. But a drug mix-up that led to a death may send her to prison, frustrating fellow caregivers.

Prosecutors filed a felony charge against Ms. Thao, igniting a debate over whether medical professionals who make unintentional yet deadly mistakes should face criminal charges, on top of civil punishment from victims and regulators.

Officials say the charge against Ms. Thao reflected a series of dangerous decisions she made that led to the July 5 death of 16-year-old Jasmine Gant, an expectant mother whose 8-pound baby boy survived.

Jasmine died after Ms. Thao mistakenly gave her a dose of epidural instead of penicillin to treat a strep infection during labor. The epidural, a potent pain reliever used during childbirth, caused Jasmine to go into cardiac arrest and die within hours.

Ms. Thao, a 41-year-old divorced mother of four, told investigators that she was in a rush to treat Jasmine and inadvertently scooped up the bag containing epidural instead of penicillin. Both medications were on the counter in the birthing suite at St. Mary's Medical Center in Madison.

The case has alarmed groups representing medical professionals who say punishment for unintentional errors should be left to regulators and the civil court system.

While calling the death tragic, they say the charge sends the wrong message at a time of nursing shortages and attempts to improve self-reporting of medical errors.

"Everyone in health care is saying uniformly what a terrible mistake this is," said Michael Cohen, president of the Institute for Safe Medication Practices, a nonprofit. "I don't believe anything like this warrants criminal charges. It sets a terrible precedent."

State regulators are investigating whether to revoke Ms. Thao's nursing license, and the victim's family is seeking compensation from the hospital. Hospital spokesman Steve Sparks said the facility no longer employs Ms. Thao but would not say if she was fired.

The charge – neglect of a patient causing great bodily harm – can carry a prison term of as much as six years. Criminal charges in such cases are virtually unprecedented, even though a report by the Institute of Medicine in July said 1.5 million Americans are injured every year by drug errors.

Charges in a medical setting have traditionally required intent – such as the assault of a patient, the repeated neglect of nursing home residents or the intentional killing of a sick patient.

In one case, a doctor and two nurses were arrested and accused of using sedatives to kill four critically ill patients in a flooded New Orleans hospital after Hurricane Katrina. They have not been formally charged.

Mr. Cohen could recall only one criminal case for an unintentional drug error, which involved three Denver nurses charged with criminally negligent homicide in the 1996 death of a newborn given the wrong medication. One nurse was acquitted; two others pleaded guilty.

Charges are a reaction to public pressure to blame individuals for fatal errors, but the drug delivery system is what is flawed and needs to improve, Mr. Cohen said.

"Julie did not want to make an error. She did not want to hurt a patient," he said. "There are many nurses who would say that could happen to any of us."

But the seven-page criminal complaint says Ms. Thao's "actions, omissions and unapproved shortcuts ... constituted a gross breach of medical protocol."

Among them: retrieving the epidural from a locked storage unit without a doctor's order, failing to scan the medication in a computer system that would have detected the mix-up, and ignoring large warning labels on the epidural.

Ms. Thao also injected the epidural too fast in an effort to save time, hastening Jasmine's death, and failed to double-check the patient, route, dose, time and medication, the complaint says.

Eric Farnsworth, an attorney representing Jasmine's family, said the family does not support the charge.

"I do not see that this nurse intended to harm this girl," he said. "But did she consciously disregard four of five different protocols that were meant to keep the girl safe? That's what the evidence looks like."