There are those who say something can’t be done, and then there are those who just do it. Dr. Mark McCallister clearly is one of the latter.

McCallister, 41, works as an emergency room physician at Pen Bay Medical Center in Rockport. Nine days ago, he opened the door to an examination room to find Barry Cook, an 80-year-old retired marine engineer from St. George, in deep trouble.

It took only seconds for McCallister to translate Cook’s symptoms — intense pain in the back and chest running down to the abdomen, pain and numbness in the leg — into the most dire of diagnoses: Cook was suffering from an aortic dissection, a tear deep in the body’s main artery that can quickly lead to a complete rupture and almost immediate death.

“It is the main line, the high-pressure hose of the body,” McCallister said. “People can die within seconds to a minute or two of it rupturing because people bleed to death so quickly.”

Cook needed surgery — and fast. And, the nearest place he could get it was at Maine Medical Center in Portland, just over 80 miles away.

It was late on a Friday afternoon. McCallister contacted Dr. John Fallon, a cardiac surgeon at Maine Medical Center, and quickly briefed him on Cook’s deteriorating condition, which had by then been confirmed with a CT scan. Fallon told McCallister to get Cook onto a LifeFlight helicopter immediately while Fallon gathered his eight-member surgical team.

“I was thinking, ‘This is great. We’re ahead of the curve here. He might stand a chance because I’m getting him down there quickly enough,’” McCallister recalled.

“It’s all hands on deck,” Fallon said. “Get him into the operating room as fast as you possibly can. (McCallister) knew, like I did, that literally every second was a higher risk of this thing completely rupturing and taking this guy’s life.”

Normally, the LifeFlight helicopter would have Cook at Maine Medical Center’s helipad in under a half hour. But, on this day, high winds along Maine’s coast had grounded the chopper.

On to Plan B — a ground ambulance staffed by paramedics who can at least try to keep the patient stable for the nearly two-hour trip to Portland. McCallister contacted Maine Medical Center’s transport center to arrange the ride.

That’s when things turned surreal.

“Unfortunately, the answer was there were ambulances around, but there were no crews available to actually drive them or do a transfer,” McCallister said.

Fallon, waiting in Portland with his team, couldn’t believe it. McCallister, truth be told, wasn’t all that surprised.

“That’s something that’s been building in Maine over the last several years, that the pandemic then kicked into overdrive,” McCallister said. Between the shortages of emergency medical personnel and the pandemic, “this is medicine in community hospitals these days…sometimes we just can’t get people the care that’s needed.”

So, there Cook lay at Pen Bay, hooked up to multiple intravenous medications to keep his blood pressure as low as possible. And, there Fallon and his team waited at Maine Med, incredulous that there was no way to get Cook to them.

And in the middle stood McCallister, who knew what we all take for granted — an ambulance with a highly skilled crew whenever and wherever we need them — isn’t always as easy as it sounds. After “several heated telephone calls,” McCallister said, he knew what he had to do.

“My relief had just come in for the end of my shift, so I had my secretary call Northeast (Ambulance), our local EMS agency, and I said, ‘Get me an ambulance, get me someone who can drive the ambulance and knows where stuff is, and just let me go,” McCallister said.

The ambulance arrived a short time later with two emergency medical technicians up front. They loaded Cook into the back, and in jumped McCallister and emergency room nurse Michaela Poor. The race was on.

Down Route 1 they barreled, lights flashing and siren wailing the whole way. In the back, McCallister and Poor had their hands full.

“A lot of times with this condition, it requires a lot of tweaking and adjusting (of the IV drips) — you’ve got to increase the first one and decrease the second one, then increase the second one … and there tends to be a lot of micromanagement that comes along with that,” he said.

Another wrinkle: McCallister is prone to motion sickness – not good when you’re speeding down a bumpy road in what is essentially a big metal box.

“I was actually trying very hard not to vomit,” McCallister said with a chuckle. “And just to speak to what a gentleman (Cook) is, he’s laying on the stretcher with his aorta going to emergency surgery and he looks up at me and sees the nausea on my face and says, ‘Doc, how are you feeling right now?’”

McCallister won the battle with his stomach. And Cook won his battle with time. The ambulance pulled into Maine Med’s emergency dock just before 9 p.m. As they prepped Cook for surgery, Fallon told McCallister he was more than welcome to stand in for the relatively rare surgery.

“You don’t invite just anybody into your O.R.,” Fallon said. “But I felt like the man deserved to watch it to completion because his actions kind of spoke to what kind of guy he is.”

McCallister, with much regret, declined the invitation.

“I can’t,” he explained to Fallon. “The ambulance is my ride home.”

The surgery, which began at 10 p.m. and lasted until 4 a.m., went off without a hitch. By late last week, Cook was out of the hospital’s intensive care unit and looking forward to getting home to his wife, Patricia, and his 100-plus-pound poodle, Zorro, who “gets down in the dumps because I’m not there.”

As for his medical adventure, Cook remembers two things: The ride — his first ever in an ambulance — was bumpy. And, when it mattered most, the doctor who could have handed Cook over to the next shift and gone home instead never left his side.

“He’s a good man,” Cook said. “I would say he’s a hero.”

“Well, I don’t know,” a humble McCallister later replied. “That’s a pretty strong word.”

So is lifesaver.