ST. LOUIS MO - Missouri officials are headed for a showdown with a federal judge after informing him that the state cannot comply with a key part of his order directing the state to change its lethal injection execution procedures.

The clash in Missouri raises two thorny questions about capital punishment that are becoming increasingly significant — one concerning judicial oversight, the other the role of the medical community.

On June 26, U.S. District Judge Fernando J. Gaitan Jr. said Missouri's current procedure created an unnecessary risk that an inmate could be subjected to "unconstitutional pain and suffering when the lethal injection drugs are administered," thus violating the 8th Amendment's prohibition of cruel and unusual punishment.

Gaitan, who was appointed by President George H.W. Bush, told state officials that, among other things, a board-certified anesthesiologist had to ensure that inmates were sedated enough during execution that they would not feel unnecessary pain.

Late Friday, Missouri proposed a new protocol to the judge in court papers filed by the office of Atty. Gen. Jay Nixon. They reported that Missouri corrections officials had been unsuccessful in finding an anesthesiologist who would participate in an execution.

Missouri officials sent letters to 298 board-certified anesthesiologists in Missouri and southern Illinois "inquiring of their willingness to participate in execution," according to the court filing by two assistant attorneys general, Michael E. Pritchett and Stephen D. Hawke. "To this date, no one has accepted."

The attorneys wrote that they were not surprised, noting that four days after Gaitan issued his order, Dr. Orin F. Guidry, president of the American Society of Anesthesiologists, sent letters to the organization's 40,000 members strongly urging them to "steer clear" of any participation in an execution. "So they have," Pritchett and Hawke said.

On Saturday, Guidry said in a telephone interview that he was "pleased that anesthesiologists have taken our advice." Guidry emphasized that he was not taking a position on capital punishment. Rather, he said, the matter is between the state and the judge and is not anesthesiologists' obligation to resolve.

In their latest brief, the state's attorneys said: "A requirement of using a board-certified anesthesiologist is a requirement that cannot presently be met. To enforce it may effectively bar implementation of the death penalty in Missouri. Surely that is not what the court intended."

In recent years, lethal injection has become the dominant mode of capital punishment in the U.S. The challenge to lethal injection in Missouri is among many pending across the country — including in California, where a hearing in federal court is set for Sept. 19 in San Jose.

Although some of the 38 states that have capital punishment offer the condemned an alternative method of execution, such as the electric chair, all use a three-stage lethal injection procedure. The first drug administered, the sedative sodium thiopental, is meant to induce sleep; the second, pancuronium bromide, paralyzes the prisoner; the third, potassium chloride, stops the heart. According to the lawsuits, sedative dosages have at times been inadequate to anesthetize inmates.