Who gets to decide when medical treatments are no longer worth pursuing and should be ended? The doctors? The patients? In the case of those who can't speak for themselves, their surrogate decision-makers?

Is discontinuing care when doctors deem all hope of recovery is gone the equivalent of allowing a patient to die — or hastening a death?

In the coming weeks, the Supreme Court of Canada's justices will be mulling over these questions and what the law says about them as they craft a judgment in a case entitled "Brian Cuthbertson, et al. versus Hassan Rasouli by his Litigation Guardian and Substitute Decision Maker, Parichehr Salasel."

The Ontario case was argued before the court Monday in a three-hour hearing. Chief Justice Beverley McLachlin closed the proceedings by saying the court was reserving judgment. No hint was given as to how soon a decision might come.

When it does, though, the Supreme Court's ruling is expected to have a profound effect on how decisions are taken in end-of-life care cases across Canada. Parties throughout the health-care system and those who scrutinize how such decisions are made are relieved the country's highest court is taking on this issue.

They hope the court will not restrict itself to making a decision on the care of Hassan Rasouli, and whether Ontario courts were correct in their interpretation of how the province's law pertains to his case.

Rather, they are looking to the high court to interpret what the Canadian common law says about whether doctors and hospitals can be obliged to provide care they think is futile and not in a patient's best interest.

'Clarity' needed, bioethicist says

University of Toronto bioethicist Kerry Bowman, who has worked in the arena of end-of-life care for years, said he used to argue that a court was the wrong venue for this type of decision.

"I don't say that anymore because in fact, the difficulties with these kinds of cases repeatedly tell us that we really must have some clarity," said Bowman, who is with the university's Joint Centre for Bioethics.

The case began with a medical tragedy that befell Rasouli, 60, just five months after he and his family immigrated to Canada from Iran in 2010.

The retired engineer underwent surgery at Toronto's Sunnybrook Health Sciences Centre in early October of that year to remove a benign brain tumour. In the days after the operation, Rasouli developed an infection in his brain that destroyed tissue in multiple parts of the organ.

For more than a year afterward, Rasouli was deemed to be in a persistent vegetative state. Earlier this year, his condition was upgraded to minimally conscious, one of the things giving his family hope that Rasouli will keep getting better.

His daughter, Mojgan Rasouli, told CBC's Ioanna Roumeliotis that she visits her father every day.

"He is my father. He feels us. We feel him," she said, sitting by his side at the hospital. During her visits, she said, she tries to make him more aware and asks him to do simple tasks, like giving her the thumbs-up sign. If he is awake and well-rested, she said, he performs well.

“It’s amazing and exciting and I’m so happy," she said.

But his doctors do not believe Rasouli is on the road to recovery. Nor do they think he is suffering from the nightmarish condition known as locked in — where a person is conscious of what is going on around him or herself, but cannot move or speak to convey that fact.

Rasouli has been tested by Dr. Adrian Owen, a neuroscientist at London's Western University who uses functional MRI scans to try to communicate with people in vegetative or minimally conscious states.

Owen has reported that about 20 per cent of such patients have some cognitive function. And in a report on Rasouli, which may be presented to the court, Owen concludes that the patient is in a very low level minimally conscious state, but is not, in his estimation, locked in.

Ventilator use brought case to top court

How this case comes to be one considered by the Supreme Court stems from the fact that Rasouli's brain damage is so profound that his body doesn't know it needs to breathe. For the past two years, he has been on a ventilator, a machine that breathes for him. Attempts to wean him off the ventilator have failed.

Two of his physicians, Dr. Brian Cuthbertson and Dr. Gordon Rubenfeld, believe it's in Rasouli's best interest to end his current treatment regime and switch to a program of palliative care.

'There is a difference between killing and letting die. This is letting die.'—Bernard Dickens, professor emeritus of health law and policy at the University of Toronto

That would mean withholding feeding and hydration, their lawyers told the Supreme Court.

(It is important to know that doctors don't act alone in such circumstances. Hospitals and the professional bodies to which they belong — in this case the Ontario College of Physicians and Surgeons — have established protocols for coming to such decisions.)

Some might feel that course of action would, under the law, be defined as actively hastening a death. But Bernard Dickens, professor emeritus of health law and policy at the University of Toronto, disagrees.

"There is a difference between killing and letting die. This is letting die. It's the natural conclusion of life," he said. "And in that sense, there is nothing unnatural or nothing wrong about it. The difficulty is the family members — sometimes patients themselves — are sometimes not willing to accept that."

Ceasing care, starting another a key point

Rasouli's wife, Parichehr Salasel, is his surrogate decision-maker. A licensed physician in Iran, she has refused to consent to starting her husband on a palliative care track. Salasel told Roumeliotis that the doctors who say her husband will not get better are entitled to their opinion, but she does not agree with them and will keep fighting for her husband.

“I talk to him every day ... And he listens to me and he responds to me as I feel it. Maybe another person doesn’t feel it. It is their problem. I don’t care," she said. "But I feel, I feel he understands me and I understand him.”

She and his family insist their faith — they are Shia Muslims — requires them to do all they can to preserve Rasouli's life. They say Rasouli would want to stay alive.

"He’s full of life. He’s a good fighter," said his daughter, Mojgan Rasouli. "And he [would] remain strong to be alive, to be with his family.”

They also reportedly believe that some movements he makes are purposeful.

Where this becomes a case of law stems from the delicate interplay between ceasing one type of care and starting another. Lawyers for Cuthbertson and Rubenfeld argue that physicians have the right to stop care if it is deemed to be of no medical value.

For instance, oncologists are not obliged to continue giving a cancer patient chemotherapy if the drugs aren't working.

Parichehr Salasel, Hassan Rasouli's wife, leaves the courtroom during a break in hearings at the Supreme Court on Monday. (Adrian Wyld/Canadian Press)

The lawyers argue that if the courts rule hospitals can be made to give care that isn't medically warranted, patients will ultimately suffer. Doctors may become reluctant to try a treatment that has a low probability — but still a chance — of working, because they may fear they won't be allowed to stop it once they have started.

The first Ontario court to hear the case said the doctors needed Salasel's consent to withdraw care.

The Ontario Court of Appeal disagreed with the lower court's interpretation of the law, but still found for Salasel. It said that under Ontario law, doctors do have the right to withhold or withdraw care. But they need consent to start a new form of treatment — in this case, palliative care. And they don't have it from Rasouli's surrogate decision maker.

The court said that where withdrawing one type of care (feeding and hydration) would lead to an imminent death, the act of withdrawing care and starting a new treatment regime (palliative care) were "integrally linked."

Health-care resources and end-of-life care

What won't be discussed in the case, but which will be the elephant in the room, some say, is the issue of health-care resources.

'Decisions about allocation of scarce resources belong at a societal level. Not at the bedside level with the doctor.'—Jocelyn Downie, a professor of law and medicine and an ethicist at Dalhousie University

"This case is not — let me be very clear — argued on resources," Bowman said. "But everyone knows that resources is a huge element of this that just sort of hangs in the air. Because it's very costly to continue on. And if we have a lot of patients like Mr. Rasouli who are ventilator dependent, there will be costs."

Jocelyn Downie, a professor of law and medicine and an ethicist at Dalhousie University in Halifax, said a discussion of how to use resources in end-of-life care should happen — but not by the bed of an individual patient.

"Decisions about allocation of scarce resources belong at a societal level. Not at the bedside level with the doctor," she said.

With files from CBC News