Physicians should abstain from discussions on how to improve lethal injection, according to one clinician who has become an outspoken critic of the execution modality.

"It might be similar to asking a fireman how better to burn down a building," Joel Zivot, MD, told MedPage Today. "I am in the business of saving lives, not taking them. I think physicians should continue to affirm the position of the standard of practice of medicine, which speaks out against killing."

Zivot is assistant professor of anesthesiology and surgery at Emory University School of Medicine and the medical director of the cardiothoracic intensive care unit at Emory University Hospital Midtown in Atlanta.

Zivot has railed against the veiled humanity of lethal injection and has worked with defense attorneys on recent death row cases, as drug shortages have sent prisons scrambling for untested alternatives.

For instance, he examined Robert Henry, who was executed in Florida in March, and wrote an editorial that appeared in USA Today ahead of Oklahoma's execution of Johnny Dale Black.

Oklahoma's botched execution of Clayton Lockett earlier this week should create momentum for physicians to break their silence on the issue if they feel compelled, Zivot said. On Friday afternoon, President Barack Obama called the situation "deeply troubling" and asked Attorney General Eric Holder to review death penalty procedures around the country.

Zivot said it seemed that Lockett died of suffocation -- "a very cruel execution, and likely a painful execution, and a terrifying execution" -- and that lethal injection should face serious inquiry as it does not appear to be meeting constitutional protections against cruel and unusual punishment."