Carmen Walker with her sons Craig, left, and Lance Walker. Photo: Supplied
Content note: This story contains discussion of medical procedures.
- Coroner's finding in Carmen Walker death upsets family
- Adverse reaction and blood loss main causes
- Human error ruled out
The family of Carmen Walker, who died following complications during a cancer procedure, are shocked and disappointed with a coroner's finding that her death was not the result of blood being drained out of her body by mistake.
Walker's sons Craig and Lance told RNZ they were bewildered by the finding, which they had hoped would provide answers for which they had waited for 14 years.
Together with plastic surgeon Dr Adam Greenbaum, who was observing the procedure in August 2010, the brothers believed the blood loss was human error and preventable.
Lance Walker said all he wanted was the truth of what happened to his mother during the isolated limb infusion (ILI) at Waikato Hospital.
That was a promise he had made to his father Bob on his death bed in 2014.
"As a family we're quite devastated and at a loss to read the final finding."
Coroner Alexander Ho found that Walker died due to complications in her melanoma treatment, including an adverse reaction to the anti-blood clotting drug protamine, and blood loss.
He found that Walker's circulating blood volume was not accidentally drained out of her leg as part of the procedure, and the blood loss was likely from a combination of other internal and external bleeding.
The ILI procedure involves cutting off the circulation to the diseased leg with tourniquets, injecting a chemotherapy drug into the leg to "bathe" the cancerous cells, washing out the limb to remove the drug and tainted blood, then releasing the tourniquets.
The family preferred Greenbaum's evidence that he noticed an "awful lot of blood in the bucket" during the washout.
Lance Walker said chunks of evidence were left out of the finding and he felt no-one had been held accountable.
Craig and his wife Linda Walker, of Whanganui, said the finding had done more damage to their family.
"[The coroner] seems to have taken 13 months sifting through the evidence to cherry-pick the least damaging narrative for those involved in Mum's procedure and avoid making any adverse comments about them."
While the coroner found the surgeon and anaesthetist had done nothing wrong, he criticised a pathologist who prompted the inquest by changing his conclusion on Walker's cause of death, for not conducting a thorough autopsy.
But Dr Ian Beer rejected that and said despite searching for one, he could find no evidence of a gastrointestional bleed, which the coroner included as being one of the other sources of blood loss.
Beer said blood loss that left Walker with a severely low haemoglobin of 28 would have been so massive he would have found it.
On the finding that Walker had an adverse reaction to protamine, Beer said a test for anaphylaxis was returned the next day and found that she was within normal range.
Plastic surgeon Dr Adam Greenbaum. Photo: Supplied
Greenbaum pointed to evidence from the lead surgeon, the anaesthetist, himself, and the coroner's expert witness - Australian surgeon Professor John Thompson, who invented the ILI procedure - as all pointing to Walker losing blood.
"None of that evidence is weighed, discussed, or quoted in the coroner's report."
Walker needed transfusions of twice her usual circulating blood volume during the 90-minute resuscitation shortly after fluid was drained from her leg into a bucket that did not have a measuring system.
Greenbaum said he could not comprehend the coroner's finding that the massive blood loss was not linked to that.
Coroner Ho made no recommendations, saying ILIs were no longer performed in New Zealand, although Te Whatu Ora confirmed a national service was still provided in Auckland.
Instead, he suggested that procedures that involve draining fluids should use a measuring cylinder, which Greenbaum said was already a worldwide standard.
"It just wasn't happening in the Waikato on that day ... If blood loss into a bucket without any measurement didn't contribute to Carmen Walker's death, and [the coroner has] gone to great lengths to specifically say that, then why [is he] bothering to suggest that measuring body fluids would make a difference?"
Greenbaum said it was already clear before the inquest that Walker died from complications.
"The coroner could and should have commented on whether those complications were unacceptable and avoidable. He failed to do that.
"The Waikato could have been a much safer place to have medical care after this inquest, and that would have been a legacy from which Carmen's family could take comfort.
"Instead, they wasted a few weeks last August reliving the horror of Carmen's death and received a desultory: 'May she rest in peace'."
RNZ put the criticisms to the coroner and was referred back to the finding.
In it, Coroner Ho said witness memories of the precise amount of blood drained during the washout could not be relied on because of the passage of time.
He said people were notoriously poor estimators, even without accounting for the other cytotoxic waste discarded into the bucket.
"I therefore consider it unsafe to accept any individual's estimate of there being 'too much' or 'perhaps too much' blood in the container. This was Dr Greenbaum's first ILI procedure. [The lead surgeon] was making his observation in the context of a query about blood loss, raising the possibility that he saw what he thought he should be looking for.
"The impact of these combined factors means that it is impossible, through no one's fault, to conduct a Goldilocks exercise of whether there was too much, too little or just the right amount of fluid in the receptacle."
He also said that there was no evidence Walker was suffering blood loss over and above what was anticipated.
The family said that they would not seek a judicial review.
