I was sitting near the back of the crowded auditorium when a man up front let out a woof of pain and lurched forward in his chair. The startled keynote speaker stopped mid-sentence and everyone in the audience tensed. Two people on either side of the stricken man helped him out of his seat, led him up to the speakers' platform, and all three disappeared backstage.

A few seconds later, an EMT rushed out, pushing the victim on a gurney. They were followed onstage by a medical team in scrubs that immediately began to triage the patient, asking him questions, checking vital signs, shouting orders, repeating information back and forth.

We'd been had — never mind that the plenary session at last spring's National Patient Safety Foundation meeting was clearly titled "Healthcare Simulation Live on Stage." For the next 45 minutes or so, we paid rapt attention as the team of doctors, nurses and support staff from Washington Hospital Center took care of the "patient" — a mannequin voiced by an actor offstage.

The clinicians participating in the simulation did not know beforehand what medical scenario they would be responding to, so their reactions were as authentic as they would have been in a real-life situation, and that provided eye-opening insights into how a medical team works — and might work better. Especially revealing was a meeting with the patient's "wife" and "sister" to discuss a miscommunication that complicated the patient's treatment. The clinicians and a risk manager had to work out who should confer with the family, how to respond to their fears and what the hospital should do to acknowledge and ameliorate their indignation — all before our eyes.

"At the end, when you saw them debriefed, those feelings were very genuine," a delighted Jeff Cooper recalled recently. "They got totally sucked into it. It was remarkable."

Such is the power of simulation to fundamentally improve the quality of workplace performance. It's been used for years in high-risk industries like aviation and nuclear power, and it's gaining enormous traction in health care, thanks in large part to the pioneering Center for Medical Simulation in Cambridge, Mass., where Cooper is executive director. Hospitals have been sending staff to Cooper's center for 20 years, and similar programs have sprung up around the world and in most major American health systems.

The basic idea is simple: Don't use real people for practice. "Ethically, we need to move away from the current apprenticeship model in which clinicians learn their techniques on actual patients," Cooper said.

The concept plays out in a variety of ways. Hospitals might send teams of staff to a simulation lab for one or more days. The focus may be narrow — a specific specialty, say, such as anesthesiology. Or it may be broader; for instance, the emergency department, with a team of doctors, nurses and EMTs. It may even involve nonclinicians.

"We have a program where we bring the hospital CEO and all the senior VPs for a day, and we have them take care of a patient," Cooper said. "They learn about key patient safety issues and they get to examine their own teamwork."

Teamwork is the name of the game. By simulating true-to-life scenarios, participants identify weaknesses in their processes, sort out roles, learn to speak up and build what Cooper calls "muscle memory" so that excellent teamwork becomes ingrained.

Simulation is not really about learning to handle crises, Cooper said. "That's my message to the CEO. It's not, 'Oh, here's another thing to practice for emergencies.' And the CEO says, "Well, we already have people in the organization to do that. We have disaster drills, people to do ACLS, people who train for codes.' That's not what this is about. This is much deeper, philosophical. It's about changing culture."

Cooper says the main mission of his center is to "teach the teachers." The people who take part in the simulation program "live in the hospitals," he says. "They'll infuse the concept into everyday practice. If you want to shift the culture, train the teachers."

As the benefits of simulation are more widely understood, hospitals everywhere are taking advantage of it. The Center for Medical Simulation has taught courses in Spain, Canada, Hong Kong, Australia and elsewhere.

Rural hospitals in the U.S. can buy their own relatively inexpensive simulators or send staff to meetings where it's offered. Some simulation organizations transport simulators on an RV, park in the hospital lot and put staff through a series of drills for a day or two.

Simulation is a potent way to make health care better and safer. "You are going to see this just grow," Cooper said.