When Nevin Katz entered the operating room, waiting for him was a small surgical hardware store's worth of equipment arranged on a tray with martial order and precision--including 198 surgical needles, 11 forceps, 78 clamps, 21 retractors, eight blades and an electric saw.

The tray, and everything on it, was surgically sterile, theoretically devoid of bacteria and other microorganisms that might give Leatherman an infection. Eileen Mattei, the scrub nurse for Leatherman's operation, had arranged that tray.

Throughout most of the operation, Mattei, who stood on Katz's right side, was responsible for seeing to it that Katz had what he needed-- quickly.

Mattei's job requires total concentration.

"Not only are you thinking about what you're presently doing," Mattei says, "you're thinking about what you're going to be doing at least 10 steps ahead. You have to. A scrub nurse can either really assist or hinder a surgeon. And I would prefer to assist the surgeon rather than hinder." By the end of an operation, which may last five hours or more, Mattei says she is "mentally exhausted" from the concentration required. Some days she may have two, or more, operations. She has worked 24 hours and longer without sleep.

Mattei, 28, fills one of six nursing positions on Georgetown University Hospital's open-heart surgery team. Nurses in Mattei's position earn between $20,000 and $30,000 a year, depending on their experience and the amount of overtime. When she is on call--every other week--she can't stray more than a half-hour's drive from the hospital. If she goes swimming at her apartment pool, she has to leave her electronic beeper with the lifeguard in case it goes off while she's in the water. She has been interrupted in the middle of dinner dates in a restaurant, and awakened at 2 a.m.--"like you don't even know where you are and you get up and go to work."

Mattei, who is single, says she likes her work, despite the hours and the strain-- standing on her feet in one spot without rest or respite for hours at a time--but concedes that "after awhile it takes its toll on you."

"What I'm doing is really a double-edged sword. I really enjoy what I'm doing. It's a tremendous challenge. I really find it fascinating. I enjoy the nurses I work with, the perfusionists. We're a good team together in many ways, personally and professionally. It's a tremendous team effort. I'd like to stress that. Each one of us relies on each other in different ways. It's a nice cohesiveness, and it's really a nice feeling in a pinch situation to see the way that everybody pulls together.

"Frankly, I don't think it's something I could do forever. If I were married and had a family, I wouldn't want to. It just takes away too much time. I would not want to give that much of my time to my job and my profession while trying to raise a family and run a home and all of that. Right now, it's not a problem. But I don't know how I would feel six months from now, a year from now, 10 years from now. I know that each one of us individually and as a group, we go through different cycles. Sometimes when we have a really hairy month, we're just doing two, three, four, five cases a day, and everybody's staying late and getting called back in the middle of the night, you know, that tends to burn one out a little bit faster than if things are just kind of pacing along. So who knows? But as I said, I could see myself doing this for another five years. Beyond that, I don't know."