The BBC's Linda Duffin reports from the High Court

But Carol Glass has said she will fight on for a legal order to force doctors to provide resuscitation and lifesaving treatment to her son if his condition should deteriorate.

A High Court judge ruled on Thursday that the "sensitive" problem was not susceptible to the "blunt tool" of judicial review.

Mrs Glass brought her case against Portsmouth Hospitals NHS Trust following an incident at St Mary's Hospital in October last year.

Fifteen members of the Glass family fought to keep 12-year-old David alive as he lay dying in a children's ward.

They entered the ward and attempted to resuscitate him by blowing raspberries in his ear and massaging his chest, the court had heard.

Challenge to doctors

David was born with hydrocephalus, and suffers from blindness, spastic quadriplegia and severe learning difficulties.

His condition deteriorated sharply in October, and doctors gave him diamorphine.

Carol Glass will seek leave to appeal

Diamorphine is a painkiller, but Mrs Glass feared it could also hasten her son's death.

Lawyers for Mrs Glass argued that the hospital trust had acted unlawfully when it decided David should "die with dignity".

However, Mr Justice Scott Baker said the court should not intervene because the October crisis was over and David was no longer a patient at St Mary's. He refused leave to appeal.

The court had earlier heard that David was likely to receive future treatment at a hospital in Southampton, not in Portsmouth.

Mr Justice Baker said: "It is a very sad case and no-one who had heard the facts and background could doubt the devoted care of the Glass family for David."

He said it was "regrettable" that the issue had not been raised at the time at the Family Division of the High Court.

He said either party could have brought a case to obtain a ruling as to what was in David's "best interests".

He concluded: "I expressly make no findings or observations about where any fault lies for the events that occurred last October, nor am I in any position to express any view about any aspect of the doctors' clinical judgment."

Mother will fight on

Leaving the court, Mrs Glass today said she was determined to continue her fight until a decision is made about her son.

Richard Stein: "The decision is worrying for parents"

She said: "I will never let this matter drop until someone is prepared to make a decision on how far doctors can go."

She said her son was "doing well" and television viewers would see him playing happily on Thursday evening.

Her solicitor, Richard Stein, read from a prepared statement.

He said: "Carol Glass is very disappointed by the judge's decision today not to clarify the ground rules affecting how and when her son, David, will be treated by doctors in the future.

"The judge said some situations should be left to the common sense and good judgement of the doctors but he didn't qualify whether this was such a case nor did he decide whether the hospital had acted lawfully in this case.

"It is most worrying for all parents that they don't know in what circumstances doctors can treat their children against their wishes without going to court.