TORONTO — If the surgical safety checklist were an actor, it would have earned a Screen Actors Guild card for the role it played in Thursday's pivotal episode of the medical drama "ER."

The safe surgery tool saved the day -- and a donor kidney destined for the ailing Dr. John Carter -- in a crucial scene in what was likely one of the most anticipated episodes in the storied show's history.

The team that designed the surgical checklist and tested it in a study published earlier this year was thrilled by the spotlight "ER" focused on a tool they believe can have a major impact on reducing deaths and complications due to surgical errors around the world.

"I have to tell you it got to me in a way I never anticipated," the team's leader, Dr. Atul Gawande of Harvard School of Public Health, admitted in an email.

"Producing a checklist that could save lives is what we on our team at the World Health Organization spent the better part of two years working to make happen. And underneath it all is a cultural change for surgery exactly like `ER' depicted on a screen -- a change from seeing ourselves as solo agents to effective teams."

"But you begin to wonder if anyone is going to get it. What those few minutes showed me is that everyone will."

Carter, played by actor Noah Wyle, had been suffering from kidney failure and waiting for a transplant. When a donor organ arrives, he's rushed to the operating room under the care of a brusque and arrogant surgeon.

Carter's mentor of old, Dr. Peter Benton (played by Eriq La Salle), asks to observe the procedure. When the surgeon in charge moves for a rapid start to proceedings, Benton intervenes, pulling out a laminated card and asking to run through the safe surgery checklist.

To the evident irritation of his colleague but with the support of other surgical team members, Benton establishes that everyone knows each other, their role, the operation to be undertaken, that Carter has no known drug allergies and that he is receiving intravenous antibiotics to lower the risk of infection.

When he asks if any members of the surgical team have any concerns, a nurse pipes up that there is no reperfusion solution in the operating room. The surgeon snipes that it won't be needed, but solution is ordered.

Later, when the surgery hits a snag, having the solution at hand ensures the success of the transplant -- a point Benton drives home. A junior member of the operating team asks Benton where he can get a copy of the checklist.

"It couldn't have been better," raved Sandra de Castro Buffington, director of the Hollywood, Health and Society program at the University of Southern California's Annenberg Norman Lear Center, who brought Gawande to meet with the writers of "ER" last fall.

The program makes medical experts available to Hollywood writers and producers with an aim of increasing the accuracy of the portrayal of medical and health issues in TV programs and in films.

In addition to taking calls from writers, the program occasionally pitches experts to shows in the hopes of bringing attention to particular issues.

Having heard of Gawande's work, de Castro Buffington thought it was a natural for some of the shows the program works with, and arranged for him to meet with writers at "ER" to describe the surgical safety checklist.

"I asked Atul: `If you could reach 20 million people in one hour with three messages about the safer surgical checklist, what would they be?"' de Castro Buffington explained from Los Angeles on Friday.

The program put together a package for writers including his talking points and background on the checklist program, which was inspired by an aviation industry program and designed at the behest of the WHO.

She said Hollywood, Health and Society heard later that "ER" would feature the checklist on the show, but had no idea it would play such a prominent role in a major storyline in an attention-grabbing episode.

Thursday's show featured the long-awaited return of former cast member George Clooney as Dr. Doug Ross, along with fellow series originals Julianna Margulies (as Ross's wife, Carol Hathaway), La Salle and Wyle.

Adding to the star power of the show was Oscar winner Susan Sarandon guesting as a grieving grandmother torn over whether to allow surgeons to harvest organs from her brain-dead grandson.

"We're thrilled," said de Castro Buffington. "We know this is going to have tremendous impact."