Christa Pike survived 2 doses of an execution drug. How is that possible?

Christa Pike regaining consciousness and speaking a week after receiving two doses of execution drugs in Tennessee has left a stunning question: How did she survive?

Attorneys for Pike, 50, called her recovery “medically unprecedented” after she was placed on a ventilator following the bungled Sept. 30 attempt to make her the first woman put to death in Tennessee in 200 years . On Tuesday, they said her prognosis is uncertain and they expect a long recovery.

Many details of the execution process remain secretive and Tennessee officials say they are investigating what went wrong.

Still, medical experts raised a few possibilities that could explain how Pike was able to survive the injections, including the potential drug quality and the placement of IV lines. Tennessee's executioners had difficulties earlier this year with IV lines for another execution, leading to it being called off.

The 5-gram dose of pentobarbital used in executions is many more times the amount than what should put someone in a medical coma, said Dr. Jonathan I. Groner, a retired pediatric general surgeon at Ohio State University College of Medicine who has studied lethal injections.

“The fact that she woke, on one hand, says she got really little of it into her system. So that’s kind of shocking,” Groner said. “It says how badly they botched the execution.”

At high doses the potent barbiturate should make a person lose consciousness, stop breathing and stop their heart.

Groner said the IV might have been placed improperly, or Pike's veins could have been fragile and burst, causing the drug to seep into the surrounding tissue instead of flowing through the bloodstream. Pike's attorneys have said she was poked with needles at least seven times in the state’s death chamber and that she has a lifelong blood disorder that makes it tough to get needles into her veins.

Another possible problem could be the drug quality, said Michaela Almgren, a South Carolina pharmacist and educator who has consulted on several lethal injection cases.

Many major pharmaceutical companies refuse to supply drugs for lethal injections, which has raised questions about how states get them. Court orders have revealed that some states have turned to compounding pharmacies , which create custom drugs from raw ingredients and operate with less regulatory oversight.

Tennessee does not disclose its drug supplier and has not said where Pike’s supply came from. Almgren said that makes it difficult to track if a drug was prepared, tested, handled and administered properly.

That also means the public may never know exactly what happened in Pike’s case.

Pike’s attorneys are seeking a court order requiring the Tennessee Department of Correction to preserve evidence, including drug lot numbers, records and other information from the attempted execution.

Outgoing Tennessee Gov. Bill Lee paused executions and ordered a “comprehensive, third-party review to determine exactly what occurred” with Pike.

Before the execution attempt, Pike’s attorneys told courts and prison officials that she had medical conditions that could complicate a lethal injection and make it agonizing.

Dr. Joel Zivot, a professor of anesthesiology and surgery in Atlanta who consulted as an expert for Pike’s legal team, said Pike has a blood-clotting disorder that causes her body to produce an excess of platelets. Her lawyers had argued that the condition could cause clotting at injection sites or bleeding that could affect her lungs.

State protocol calls for a second dose of pentobarbital if the first doesn’t result in death, but it doesn't spell out what to do if an inmate survives the second injection.

The attempted execution got underway around 7:30 p.m. on Sept. 30 when Pike was given a chance to make a final statement. About five minutes later, Pike raised her head and said her arm was hurting. At some point she appeared to lose consciousness, but she could be heard audibly breathing until media were escorted from the witness room at 8:53 p.m. An ambulance arrived at the prison at 9:14 p.m. to take Pike to a hospital.

When Pike arrived at the hospital, doctors likely tried to stabilize her breathing, checked how much pentobarbital was in her system and worked to quickly flush it out, said Dr. Michael Baden, the former chief medical examiner of New York City. Doctors may have also been dealing with muscle damage, both from the effects of the pentobarbital and because some may have entered muscle tissue near the injection site, he said.

Pike’s lawyers said her arms were left burned and blistered from the failed attempt. She was unconscious and on a ventilator for several days.

“She was very fortunate that there was enough (pentobarbital) to put her into a deep sleep, but they were able to keep her breathing going and they were able to start flushing it out,” Zivot said.

Associated Press writer Kim Chandler in Montgomery, Alabama, contributed to this report.