The government and health chiefs have been accused of failing to tackle widespread confusion and uncertainty over the imposition of "do not resuscitate" orders on seriously-ill patients which are distressing many families.
Three Court of Appeal judges are being asked to intervene by David Tracey, who says his late wife Janet was subjected to an unlawful DNR order at Addenbrooke's Hospital in Cambridge.
The hospital is accused of breaching the human rights of terminally-ill Janet Tracey, 63, because it did not consult her before the order was placed on her records.
Such notices are intended to ensure that a patient dies in a dignified and peaceful manner but have become the subject of controversy.
Philip Havers QC, for Mr Tracey and his family, said the orders were routinely being used in a manner which did take into account the views of patients and were capable of being confusing and contradictory.
He said they were also contrary to Article 8 of the European Convention on Human Rights, which safeguards respect for patients' private lives.
Mr Havers argued that Health Secretary Jeremy Hunt "must step in and himself issue national guidance addressed to all parts of the NHS".
Patients were entitled, as a minimum, to be "notified, involved and have the right to seek a second opinion" before DNR orders were made, he said.
Mrs Tracey, a care home manager, died following a transfer to Addenbrooke's after breaking her neck in a car crash on February 19, 2011 - two weeks after being diagnosed with terminal lung cancer.
A DNR notice was placed on her records, but it was cancelled five days later after it was challenged by her family.
A second notice which followed two days before Mrs Tracey's death on March 7 2011 was put in place with the agreement of her family.
Her widowed husband decided to mount a legal challenge against the first notice, with the support of the Equality and Human Rights Commission (EHRC).
Mr Tracey, 66, a retired engineer, was at court and described the two-day appeal hearing as an "opportunity to remedy the current lack of information, making a real difference to other families while recognising the wrong done to Janet".
In 2012, High Court judge Mrs Justice Nicola Davies ruled the failure to inform or involve Mrs Tracey in the making of the first DNR order had "minimal causative effect" because it had been cancelled.
The judge halted Mr Tracey's application for judicial review against Cambridge University Hospitals NHS Foundation Trust and the Health Secretary.
The Trust emphasised the High Court had found that Addenbrooke's doctors acted "professionally and in the best interest of Mrs Tracey."
But in 2013 the appeal court itself decided there should be a full hearing because points raised in relation to consultation with patients and the right to a second opinion were "matters of some general importance".
Mrs Tracey's daughter, Kate Masters, 47, said: "The situation really has to change so that no other families are left like mine are.
"How someone's end of life is handled really does live with the family forever."
The hearing will continue tomorrow.