Heather Gunter will never forget the sound of her son's heart slowing, then stopping, as she hugged him while he died.
Fit, healthy, 15-year-old Matt Gunter developed pulmonary oedema after having his appendix removed at Grey Base Hospital four days earlier.
However, it was not diagnosed and he suffered a cardiac arrest the day after his operation, leading to his death three days later.
Health and Disability Commissioner (HDC) Anthony Hill today released a report into Matt's death in which he criticises a locum anaethestist, two nurses and the West Coast District Health Board (DHB).
Mr Hill said in his report Matt was a "fit, healthy" teenager whose surgery was uneventful.
However, soon after he stopped breathing and was treated for what was believed to be a spasm in his laryngeal cords.
He then suffered a coughing fit while still in the post-anaethesia care unit and coughed up blood - something the anaesthetist attributed to him having a tube down his throat to help him breath during the operation.
The levels of oxygen in his blood were also lower than they should have been.
Mr Hill said Matt was given oxygen before being transferred to the hospital's children's ward.
His oxygen levels were monitored until about 5am but he was not then checked until 6.30am, when he was found to be in cardiac arrest. He was resuscitated and later airlifted to Christchurch hospital, where he died three days later.
Mr Hill said in his report there were serious failings by the anaesthetist, two nurses - one of whom faces possible legal action - and the DHB.
Matt's mother, Heather Gunter, today released a statement in which she said a lack of care after his operation was "the main contributing factor in his death".
"I have read every report that I was allowed to read regarding Matt's death two-and-a-half years ago and the conclusion has always remained the same.
"This was a totally avoidable death and a waste of a young man's life," she said.
"As I hugged my son, I will never forget the sound of his heartbeat slowing down before stopping forever.
"My heart broke that day too. I hope that no one ever has to go through what we have and I encourage all of you to feel empowered to ask questions as patients, family, nurses and doctors.
"Our lives and those of our loved ones are worth it."
She said names of the staff involved should be made public.
"The bottom line is that Matt should not have died there was no reason he should have died.
"Pulmonary oedema is reversible, people don't die of it, but it's only reversible if you know of know what's going on."
DHB accepts findings
West Coast District Health Board chief executive Dave Meates released a statement in which he "unreservedly apologised to the Gunter family for the tragic death of Matthew".
"We deeply regret that in this instance our systems did not support staff responsible for caring for Matthew to provide care of an acceptable quality.
"The West Coast DHB accepts all the HDC's findings."
It had implemented changes which had reduced the possibility of a similar situation in future, Mr Meates said.
Those changes included the standardisation of paediatric emergency trolleys, comprehensive resuscitation training across the system, ongoing training for nurses on monitoring, documentation and critical thinking and reduced numbers of locums working on the West Coast.
"Throughout this review process we have been working with the Gunter family to ensure they are kept updated about the work we are doing and to incorporate their feedback," Mr Meates said.
"I am confident that this process will result in improved care and better outcomes for patients."