Doctor’s version of Waikato Hospital patient Carmen Walker’s death questioned at inquest

Carmen Walker died after a treatment called isolated limb infusion at Waikato Hospital in 2010. Now an inquest is set to determine her cause of death. Photo / Stuart Munro

A plastic surgeon who was observing a procedure on a Waikato Hospital patient was the doctor who drained her blood, which led to her death, an anaesthetist and perfusionist involved claim.

But Dr Adam Greenbaum has told an inquest into Carmen Walker’s death he did not perform the final exsanguination of the patient during the isolated limb infusion (ILI) in August 2010.

The opening of Walker’s inquest today heard that Greenbaum was not the surgeon in charge of the procedure but, under questioning he agreed exsanguination, a necessary part of the procedure, would only have been performed by the surgeon or himself.

However, Greenbaum was not “scrubbed in” that day and was only observing the procedure.

Greenbaum recalled the moment he noticed a washout container with Walker’s blood as being the first time anyone expressed alarm at the volume of blood in it.

“It has been almost 13 years and this story has been told many times, but I remember with clarity saying ‘there’s an awful lot of blood in that bucket’,” Greenbaum said.

Dr Adam Greenbaum gave more than six hours of evidence on the first day of the Coronial inquest into the death of Carmen Walker. Photo / Mike Scott

Walker suffered a cardiac arrest during the procedure to treat melanoma and died hours later in the intensive care unit.

A coronial inquest was ordered more than a decade later when a pathologist changed his conclusion on 78-year-old Walker’s cause of death, originally concluded as cardiogenic shock - shock that results from a failing heart.

The inquest got underway today in the Hamilton District Court with the testimony of Greenbaum, who has campaigned with the Whanganui woman’s sons Lance and Craig Walker for answers over what went wrong that day.

The ILI allowed high doses of chemotherapy to be washed through Walker’s lower leg to treat melanoma that had spread from her right ankle.

At the time the technique used a pump to circulate the chemotherapy drug and a tourniquet to prevent the concentrated chemo from entering the rest of the body.

Greenbaum told Coroner Alexander Ho the surgeon that day, who has interim name suppression, said of the blood in the bucket: “It looks a lot, but it’s mixed with the perfusion fluid, and a little bit of blood goes a long way”.

Greenbaum, an English-trained experienced plastic surgeon with advanced trauma training, said he turned to the perfusionist, who also has interim name suppression, and asked how he was measuring the fluid to know how much of it was blood.

“It was immediately after he replied ‘I didn’t need to measure it, because I know what has gone in and so I know what has come out’, that Carmen’s blood pressure plummeted, and she had a cardiac arrest,” Greenbaum said.

Coroner Alexander Ho will preside over the three-week inquest at the Hamilton District Court. Photo / Mike Scott

A resuscitation effort swung into action and Greenbaum said an emergency crash call team was summoned, though that is disputed by the anaesthetist, who also has interim name suppression.

Initially, Walker was treated for anaphylaxis and when that didn’t help an on-call emergency anaesthetist performed a trans-oesophageal echocardiogram (TOE) that showed the left ventricle of her heart was “very empty”.

Greenbaum said at that point “it became clear that there was no anaphylactic reaction, nor anything wrong with Carmen’s heart”.

“The problem was that her heart had nothing to pump, because all her blood had been emptied into the bucket, and so her heart was pumping against a vacuum in an empty system of arteries and veins.”

Chris Gudsell, KC, assisting the Coroner, said the anaesthetist and perfusionist’s evidence is that it was Greenbaum who performed the final exsanguination though Greenbaum denied this.

By the time it was discovered Walker had no blood in her left ventricle, she was in “pulseless electrical activity” and the anaesthetist commented she was unlikely to survive the night, the inquest heard.

Aspects of Greenbaum’s evidence was challenged by lawyers for the surgeon, perfusionist, charge nurse and anaesthetist, in what was at times a technical medical discussion.

Paul White, for Te Whatu Ora Waikato, said the perfusionist’s evidence was that he didn’t know who Greenbaum was and never spoke to him during the procedure, which was done in the radiology department rather than a hospital operating theatre.

The perfusionist also said he was not in the room when Walker’s blood pressure dropped and only came back when he was alerted to her crashing.

Adam Holloway for the surgeon pointed to various parts of Greenbaum’s evidence as being hearsay and questioned exactly when the doctor raised concern at the blood in the bucket.

Lance Walker told the inquest his mum never got to see her grandchildren get married or meet four of her great-grandchildren. Photo / Mike Scott

The inquest heard Greenbaum wasn’t the only doctor concerned with the amount of blood in the bucket: the surgeon also considered it, as well as the emergency anaesthetist.

Much focus was on the exact timing of events during the procedure as well as on notes that Greenbaum said he made in Walker’s file but were later missing.

The inquest also discussed the longer-than-usual length of time it took to insert catheters into Walker because of her hardened arteries with Greenbaum saying a scan should have been performed to check the tourniquet was working effectively.

Lance Walker opened the inquest saying his father Bob never got over the death of his wife and “soulmate” of 50 years, and when he was found by Craig lying on the floor after a massive stroke he had Walker’s medical notes at his side.

Lance recalled he spoke to his mother on the phone as she was wheeled to the procedure and she was in good spirits.

“She trusted that she would be in good hands.”

Walker said she’d call her youngest son after surgery. She never did.

Instead, he got a call from his sister-in-law Linda Walker with the shocking news his mother had died.

“It was like a lightning bolt through my heart and I struggled to believe it as I had only spoken to her hours before and she was so full of life.”

On opening the inquest, Ho acknowledged the Walker family’s long wait for answers and said the inquest would be a fact-finding exercise to try to get to the truth of what happened.

He said the objective was not to apportion blame and there may be answers that did not sit comfortably with some.

Any damage to reputation was unavoidable, but it was not a witch hunt.

“The unanswered questions about her death have been hanging over many for a long time and I’m hopeful this inquest can help with that.”

Natalie Akoorie is the Open Justice deputy editor, based in Waikato and covering crime and justice nationally. Natalie first joined the Herald in 2011 and has been a journalist in New Zealand and overseas for 27 years, recently covering health, social issues, local government, and the regions.