CARSON CITY — While the U.S. Supreme Court on Wednesday upheld a lethal injection method that’s similar to Nevada’s, the state’s highest court won’t immediately lift a stay that has delayed a convicted murderer’s execution.

State Supreme Court spokesman Bill Gang said justices will review the U.S. Supreme Court ruling that upheld Kentucky’s use of lethal injections to determine its effect on pending Nevada cases, including that of condemned inmate William Castillo.

“There’s not just an automatic dropping of the (Castillo) stay,” said Gang, adding that he couldn’t say how long the state high court’s review would take.

The state Supreme Court halted Castillo’s execution in mid-October, just 90 minutes before he was to get a lethal injection for beating an elderly Las Vegas woman to death with a tire iron.

State Corrections Director Howard Skolnik said Castillo, who has declined to file appeals that could keep him alive, is the only one of the 84 convicts under sentence of death in Nevada whose execution is being delayed by a court stay.

“We don’t have anything on the table right now,” Skolnik said. “Castillo is still on a stay, and of course still has the right if he chooses to appeal his case and stop everything. I do not know what he will do next. That’s up to him.”

“What we will do is whatever the courts and the law require,” Skolnik added.

Attorney General Catherine Cortez Masto said she won’t ask the state Supreme Court to lift its stay “at this point in time.” The attorney general said she’ll wait to see whether justices “take any action on their own” following their review of the latest ruling.

Because of concerns expressed in the opinion by one justice about the use of pancuronium bromide, a muscle relaxant, in executions, a key element of the ACLU’s argument against Nevada’s execution method remains alive, said Lee Rowland of the American Civil Liberties Union of NevadA.

The drug, one of three used in a lethal “cocktail” both in Nevada and Kentucky executions, “serves no purpose other than to mask pain,” Rowland added. The ACLU contends that’s a constitutional First Amendment violation because witnesses don’t see what a condemned inmate experiences when the drugs are injected.

Nevada’s injection formula also includes sodium thiopental, a “downer” that causes unconsciousness and death in some cases, and potassium chloride, which stops the heart.

In the Castillo case, the state Supreme Court has received legal briefs from both prosecutors trying to get the stay lifted and from death penalty opponents. But a date for oral arguments has not been set.