A Japanese court ruling handing a suspended sentence to a doctor who removed a comatose patient’s breathing tube and injected him with muscle relaxant is raising questions on when to end life support.

Friday’s ruling came as the United States was gripped by a highly politicized confrontation over the case of Terri Schiavo, a brain-damaged Florida woman at the centre of a national debate over the right to die.

A court in Yokohama, near Tokyo, convicted Setsuko Soda, 50, of taking the life of a 58-year-old comatose man and neglecting her duties as a doctor, and sentenced her to three years in prison, suspended for five years.

Prosecutors had demanded five years in jail.

Soda pleaded not guilty, and her defense team said she had acted in line with the family’s wishes by removing the breathing tube several weeks after the man was admitted with cardiac and respiratory arrest following a severe asthma attack. The family denied asking her to remove the tube.

Soda injected the muscle relaxant to ease the patient’s breathing difficulties after the tube was removed.

Passing sentence, the presiding judge said that Soda had failed in her duties as a doctor because it was too early to say the patient would not have recovered and to stop treatment.

But he suspended the prison term because he said Soda had acted out of a belief that what she was doing would benefit the patient and his family by allowing him to die in a natural way.

The issue of brain death has long been an uncomfortable topic in Japan, where heart stoppage was traditionally seen as the definition of death. Even now, many people still oppose the concept, including some doctors.

It was only in 1997 that Japan enacted a law permitting organ transplants from brain-dead donors, and there has been little public discussion of when to withdraw life support or the right to die.

Debate has also been hampered by a cultural dislike of discussing death so strong that it borders on superstition. The number “four” is even seen as unlucky because one pronunciation of the word is a homonym for death.

As a result, Friday’s Yokohama ruling is seen as raising difficult questions.

Noting that there are no laws on how to determine when to end life support, the liberal daily Asahi Shimbun lauded the court decision for ruling in favor of extending life.

“Efforts must be made to determine what the patient would have wanted, either through a written document or their family’s best guess,” the paper said in an editorial.

“When it is impossible to determine what the patient would have wished, however, the decision must be made in favor of doing everything possible to save their life.”