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How do you keep blood flowing? This Petoskey perfusionist can tell you.

Perfusionist Terry Ennis stands by his equipment in the OR.
As a perfusionist, Terry Ennis is responsible for operating the heart-lung machine during open-heart surgery. The machine includes a series of pumps, an oxygenator and a heater/cooler for the patient’s blood. (Photo: Courtesy of Terry Ennis)

When Terry Ennis was a boy, his mother would take him to visit the cemetery where her sister was buried.

"My mom would always say, 'She died of a hole in her heart,' and I had no idea what that was," Ennis says.

He was a curious kid, and when he got older, he looked it up.

"It was an ASD — an atrial septal defect, which is a hole between the two upper chambers of the heart," Ennis said. "I got interested in medicine and I wasn’t sure what I wanted to do. And when I found out about perfusion it was like, 'Wow! This is something that could have saved her if it had been around at that time.' "

Today, Ennis is a perfusionist at McLaren Northern Michigan Hospital in Petoskey.

Ennis stands with a McClaren Northern Michigan Hospital surgical team
Open-heart surgery requires a whole team of medical staff. The cardio-vascular operating room at McClaren Northern Michigan Hospital in Petoskey is about 600 square feet to accommodate all the necessary people and equipment. Shown here after completing a surgery is the crew (from left to right): Felica Tulgestke, anesthesiologist; Carol Sayan, anesthesia technologist; Rhonda Marvar, anesthesiologist; Terry Ennis, perfusionist; Maggie Fauser, perfusionist; Marty Linn, cardiovascular physician assistant; Chris Akins, cardiovascular surgeon; Nellie Warmbein Talbot, surgical Scrub technologist; Karley Doucette, circulating nurse; and Kelsey Pischner, surgical scrub technologist. (Photo: Terry Ennis)

He runs the heart-lung machine during open heart surgery. It’s called “a machine,” but really, it’s several devices: a series of pumps, plus an oxygenator and a heater-cooler.

But Ennis’s job is much more complicated than just turning on the machine and letting it run.

"You need to be a forward-thinking person, where you’re thinking a couple of moves ahead.  Because every minute you’re on the bypass machine is another minute something can happen," he says.

And he has a lot to keep track of.

How much oxygen and carbon dioxide are in the blood? What’s the clotting time? The glucose level? Are the pressure and temperature of the blood OK? Are both sides of the brain are getting enough blood?

Ennis adjusts the machine and, when necessary, injects medications through the pumps to keep everything in the correct range. He works in close coordination with the anesthesiologist and the rest of the surgical team.

“We have to let each other know what each other is doing. They could be giving a drug that vasodilates and we want to constrict, and without us talking, we’d be working against each other," he says.

The pumps Ennis runs are each about the size of a tuna can. A small disc with fins on top spins inside the clear plastic pump. He compares the pumps to an amusement park ride.

Ennis holds one of the pumps that circulates blood during open-heart surgery.
Ennis holds one of the pumps that circulates blood during open-heart surgery. Open-heart surgery is a general term which includes coronary artery bypass surgery, valve repair or replacement and closure of an atrial septal defect, which is a hole in the wall which separates the two upper chambers of the heart. (Photo: Cheryl Bartz/Red Pine Radio)

“You remember going to the fairs where you’d stand against the walls, and they’d spin it and you’d be pinned against the wall?  Well, that’s actually what this does,” he says.

The spinning fins draw “used” blood in the top and then fling it out a side port by centrifugal force — just like that amusement park ride.

The clear plastic pump which circulates the patient’s blood contains a disc with fins.
The clear plastic pump which circulates the patient’s blood contains a disc with fins. As it spins, it draws blood in from the top (or left, in this photo) and propels it out the port on the side of the “can.” Magnets are used to spin the disc and do not come in contact with blood. Cleanup is easy because the pump, tubing and everything that contacts blood is disposable. (Photo: Terry Ennis)

The machine has a steady flow, so the patient has no pulse while they are “on bypass.”

“This is something that’s very intense at times and very boring at other times," he says.

He says his scariest moment — still vivid after decades — occurred when a nurse bent down in the narrow space between the heart/lung machine and the operating table to pick something up from the floor.

"As she pulled back, her coat got caught on part of my equipment and it cracked," he says.

Ennis was going to have to shut down the machine. The patient would have NO circulation for the duration of the repair.

If the interruption lasted more than four minutes, the patient’s brain cells might begin to die. That could mean brain damage and stroke-like symptoms.

Terry had just four minutes to get a replacement part, install it in the pump and start the patient’s blood circulating again.

He yelled to the doctor, “Just keep working!”

He ran to the supply room, got the part, installed it, and restarted circulation to the patient in under three minutes. A whole minute to spare.

"Everything kicked in automatically," he said. "I didn’t have to think about what I was doing. I just did it."

Ennis has been a perfusionist for more than 40 years, and the heart-lung machine has been in use even longer — about 70 years. The technology has made huge advances.

A cell saver is another piece of equipment operated by a perfusionist.
A cell saver is another piece of equipment operated by a perfusionist. This machine is used in surgeries other than open-heart where the patient might lose a significant amount of blood. The machine collects the blood and separates the red blood cells to return to the patient. It can be an alternative to giving the patient blood from a donor. (Photo: Terry Ennis)

“Back in the early 80s, before we had a lot of sophisticated monitors, a perfusionist I knew would take a pack of Marlboros and he’d put it on the pump right near the line that had the oxygenated blood in it," he said. "And he knew that if the blood looked like the red Marlboro pack, we were well oxygenated.”

Ennis has a bachelor’s degree in physiology and biochemistry plus certification in perfusion technology from Wayne State University, but some perfusionists get all their training on the job.

In fact, you don’t even need a license to be a perfusionist in Michigan. Your barber and cosmetologist are required to have a license, but not your perfusionist.

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