One of the country's top medical centers is trying to find out how it botched a heart-lung transplant that was supposed to save the life of a 17-year-old girl but instead put her closer to death.

Jesica Santillan was in critical condition early Wednesday at Duke University Hospital after mistakenly being given organs that didn't match her type O-positive blood.

The hospital has acknowledged making the mistake — although it still does not know how it happened. Dr. William Fulkerson, Duke's chief executive officer, said the hospital is investigating the mistake and will determine whether any staff should be disciplined.

The girl was given organs from a donor with type-A blood during an operation Feb. 7. Antibodies in her blood are trying to destroy the organs since their blood type is different.

Family and friends said Jesica suffered a near-fatal heart attack three days after the operation and a seizure Sunday. A machine has been keeping her heart and lungs going.

Family friend Mack Mahoney said supporters believe Jesica's life can be saved if a donor is found in the next few days. He said Jesica is small for her age — 5-foot-2 and 85 pounds — and the donated organs would likely come from a child.

The teen's mother, Magdalena Santillan, pleaded for anyone facing a child's death to consider donating the organs. "Please help me find the organs that my daughter needs to live," she said.

The organs, flown from Boston to Durham 10 days ago, were sent with paperwork correctly listing the donor's type-A blood, said Sean Fitzpatrick of the New England Organ Bank, which sent the organs.

According to Carolina Donor Services, an organ procurement organization, the heart and lung became available from a donor in New England and were offered by the New England Organ Bank after being matched to two North Carolina patients on a national database.

Two Duke surgeons declined the organs but a third Duke surgeon requested them for Santillan, Carolina Donor Services said in a written statement late Tuesday. The organization did not identify the doctor.

Duke started its organ transplant program in 1965. The hospital performed the first successful heart transplant in North Carolina in 1985 and performs the largest number of lung transplants in the United States.

The university performed its first combined heart-lung transplant in 1992. Since then, 20 such operations have been performed, the university said.

Jesica needed the transplant because a heart deformity kept her lungs from getting oxygen into her blood. Her parents paid an immigrant smuggler to get the family into the United States from Mexico three years ago, in part for the better odds of landing a transplant for Jesica.

"I said I was putting my daughter in God's hands, but it turned out the doctors made a big mistake," Magdalena Santillan said through a translator Tuesday.

Duke University Hospital will now add another layer of confirmation to the organ donation process, Fulkerson said. The measures include transplant coordination staffers, who concentrate on preparing patients for surgery, independently verifying that the organs are compatible. Previously, only the surgical staff verified compatibility.

"This was a tragic event and our expectation is that, with these new procedures, this will not happen again," hospital spokesman Richard Puff said. "We've done thousands of organ transplants and it's never happened before."