Carmen Walker died after an isolated limb infusion at Waikato Hospital in 2010. Photo / Stuart Munro
The death of Carmen Walker was a medical misadventure according to the pathologist who performed her autopsy following a melanoma procedure that went wrong at Waikato Hospital.
Dr Ian Beer has told an inquest into the 78-year-old Whanganui woman’s death he was only given a clinical note and not Walker’s complete medical record when he was tasked with the coronial post-mortem on August 4, 2010 - 12 hours after she died.
Beer concluded Walker died of cardiogenic shock - shock caused by a failing heart - but in 2021, after reviewing an expert’s advice to the Health and Disability Commissioner written in 2013, he changed his conclusion to hypovolaemic shock caused by massive blood loss.
When Beer conducted the autopsy he was unaware Walker’s haemoglobin dived to 28, a level incompatible with life, and that she underwent significant blood transfusions during the 90-minute resuscitation, after suffering a cardiac arrest at the end of the isolated limb infusion (ILI).
Beer told the inquest in front of Coroner Alexander Ho in the Hamilton District Court, it was not the first time the full hospital notes had not made it to the mortuary and autopsy findings were often corrected or refined after the notes arrived.
In Walker’s case, the clinical note indicated a massive gastrointestinal (GI) haemorrhage as the cause of blood loss, suspected by doctors as the reason the left ventricle of her heart was found “very empty” after the patient “crashed”.
Beer said the notes were “clearly incomplete” and his working diagnosis of “hypovolaemic shock from a massive gastrointestinal haemorrhage” changed when he found no evidence of any haemorrhage or source of internal bleeding.
This was contrary to the intensive care nurse’s notes that Walker suffered melena - a rectal discharge indicative of internal bleeding more than 12 hours old - and her ICU discharge summary that noted the great-grandmother’s “terminal event” was a massive rectal bleed.
“My mistake that day was that I failed to speak directly with the clinical team when I could not find any evidence of the massive gastrointestinal haemorrhage that the referral note said was suspected,” Beer said.
“That may have given them the opportunity to point out the factors pointing to hypovolaemic shock due to blood loss. That would have then led on to answering the next question of where all of Mrs Walker’s blood went.”
In April 2011 Coroner Gordon Matenga relied on Beer’s finding and suggestions from the surgeon to conclude without inquest that Walker’s death was due to cardiogenic shock.
Beer said he was not asked to contribute to the hospital’s internal investigation into the cause of death later that year.
He said the surgeon, who has name suppression, contacted him in 2013 as then Health and Disability Commissioner Anthony Hill investigated, and asked whether there could be any lesion that might cause massive GI haemorrhage that might have been missed.
Beer could only think of angiodysplasia, a common age-related lesion that causes rectal bleeding in the elderly.
What Beer didn’t know was that Royal Adelaide Hospital Associate Professor Dr Susan Neuhaus, a surgical oncologist with a speciality interest in melanoma, advised Hill Walker died of massive blood loss due to leaking tourniquets.
Neuhaus said the tourniquets failed to properly isolate the right leg that was being bathed in the concentrated chemotherapy drug melphalan, and as a result most of the blood circulating in the rest of Walker’s body drained out of her into a bucket meant to be collecting tainted blood and drug waste from the limb.
That volume was not monitored or measured, she said, “and the team failed to realise the extend of the problem until her cardiac arrest”.
Beer said one lesson from Walker’s tragic demise should be the insistence that complete medical records are available before an autopsy begins.
The other lesson was the “silo mentality that has occurred in this case has undermined the preferable collegial way of sharing information”.
Beer said not only did he not know about the low haemoglobin, empty left ventricle and substantial blood transfusion during the autopsy, he also did not know Walker had been given heparin.
The blood-thinning drug prevents clotting during surgeries. Nor did Beer know about the 30ml of the highly anaphylactic drug protamine given to begin reversing the heparin moments before Walker “collapsed”.
He claimed the silo effect was demonstrated by:
He said this silo was “certainly not” the usual collaborative way doctors exchanged information in managing patients.
“This case was always an iatrogenic death. In simple words, death resulting from misadventure in a medical procedure.”
However, Beer was questioned about whether he did actually have the full notes, how many autopsies he had performed without them, and why his descriptions in Walker’s case had changed with the passage of time. It was also acknowledged he was not an expert witness.
Earlier in the inquest the surgeon contradicted the anaesthetist, who also has name suppression, when he said observing surgeon Dr Adam Greenbaum was “banging on” about the amount of blood in the bucket during the procedure, before Walker’s blood pressure collapsed.
When asked why the volume of blood was not measured the surgeon said up until about 2003 the waste was suctioned into containers with precise measurements but following a complaint from an anaesthetist the system was changed and what the ILI team ended up with was “a crap measuring system”.
He said the case had “mystified” him because if the tourniquet was leaking continuously there should have been evidence of that in Walker’s leg and also in her condition.
“Why was she not showing problems at the time of losing the blood?”
The lawyer assisting the Coroner, Chris Gudsell, KC, told the surgeon accurate measurement of what “you are taking from the limb was critical in this procedure”.
“You’re in charge of the surgery. Do you put your hand up and say ‘We mucked up here’?” Gudsell asked.
The surgeon said yes. “We should have had a much better measuring system.”
But the surgeon, who earlier admitted he was not properly trained in ILI, blamed bureaucracy and public hospital underfunding on his inability to access an appropriate measuring container.
“We were just clinicians trying to help people who had a terrible problem.”
The inquest continues next week.
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.
The prisoner was there for 'medical oversight'.