Seven years after hip replacement surgery a patient died from heart failure, caused by human error in diagnosing a build up of heavy metal toxicity in his system, the deputy health and disability commissioner has ruled.
Seven years after hip replacement surgery a patient died from heart failure, caused by human error in diagnosing a build up of heavy metal toxicity in his system, the deputy health and disability commissioner has ruled.
Human error at a variety of levels has been blamed after a patient who had two hip replacement surgeries died of heart failure following an undiagnosed build-up of heavy metal toxicity in his system.
The man underwent metal-on-metal hip replacement surgeries in 2006 and 2012. In 2013 had a review at the South Canterbury District Health Board (SCDHB) which included blood tests for cobalt and chromium levels.
The cobalt and chromium test results significantly exceeded the normal reference levels but, despite this, no action was taken on the results, Deputy Health and Disability Commissioner Dr Vanessa Caldwell said in a report released today.
“At the time, SCDHB had no electronic sign-off process, and it appears that the paper results were not sighted or actioned by the orthopaedic surgeon or any other clinician, and the man was not scheduled for follow-up orthopaedic review of his hip replacements.”
Between 2013 and 2019 the man, who was aged in his 50s, presented to hospital with various health issues, including heart failure, but did not receive an orthopaedic review during this period.
His cobalt and chromium levels were not tested again until he was admitted to hospital in 2019, following an increase in his heart rate, shortness of breath, and swelling. The patient was advised of the missed results.
“At this time, the results showed significantly elevated levels, indicating heavy metal toxicity, which clinicians believed could potentially explain the man’s heart failure.”
To treat the toxicity the man was given calcium disodium edetate (EDTA), which is rarely used in New Zealand, as an antidote but the only stock available had passed its expiry date.
After a safety assessment was undertaken, and, because of the urgency of the situation, clinicians treated the man with the expired stock but he died.
Caldwell found the SCDHB, now Te Whatu Ora South Canterbury, in breach of the Code of Health and Disability Services Consumers’ Rights by failing to follow-up on the man’s significantly abnormal test results.
“SCDHB did not provide the man with the timely, competent, and appropriate services he needed based on his significantly abnormal chromium and cobalt test results,” she said.
“This meant the heavy cobalt toxicity remained undiagnosed, and this contributed to the man’s eventual heart failure.”
Deputy Health and Disability Commissioner Vanessa Caldwell has ruled a radiologist had missed two opportunities to identify a mass in a 70-year-old patient's chest x-rays which turned out to be cancer.
Caldwell ruled the SCDHB was responsible for the failings in the man’s care, noting it was the responsibility of healthcare organisations to ensure robust systems were in place to minimise the risk of such errors occurring.
“SCDHB’s system for receiving and communicating laboratory test results to clinicians was inadequate and prone to human error, and SCDHB did not have safety-netting steps in place to mitigate this.”
Human error also occurred in the orthopaedic administrative process in booking the man’s follow-up appointment and no proactive steps were taken to ensure he was reviewed in accordance with the health board’s relevant policies and guidelines, resulting in no further post-operative follow-up between 2013 and 2019.
Caldwell cleared the surgeon of any culpability for the missed results and didn’t breach the code as the errors in the paper-based system did not alert them to the abnormal results.
The health board developed a form in 2014 to record when metal ion levels, X-rays, and CT scans were requested and signed off as viewed and introduced specific consultant folders to store results until they were signed off.
A register for patients who had received a metal-on-metal hip implant within Southern Canterbury (including at the private hospital) from September 6 to September 14, 2012, has been established and an audit of patients on the register occurred every three years and examined a variety of factors.
In addition, Caldwell requested the Te Whatu Ora South Canterbury provide HDC with a summary of a recent audit of the existing register of patients with metal-on-metal hip replacements, and steps taken to address any issues identified.
Caldwell also requested an update on the implementation and effectiveness of its existing protocol for long-term management of total hip replacements, and a summary of the changes implemented to ensure that diagnostic testing and investigations ordered for orthopaedic patients have been received and actioned.
Finally it was recommended Te Whatu Ora South Canterbury make an apology be made to the man’s family.
The decision came as a radiologist at another former district health board, that was not identified, was slammed for twice failing to identify a mass in a patient’s chest x-rays which turned out to be cancer.
Caldwell ruled the health professional had breached the Code of Health and Disability Services Consumers’ Rights.
“For failing to identify the mass in chest X-rays in 2018 and 2019, the radiologist did not provide the consumer with an appropriate standard of care.”
Caldwel ruled a radiologist exercising reasonable care and skill would have detected the mass in the 70-year-old man’s chest but it couldn’t be determined whether earlier detection of the lung cancer would have changed the long-term prognosis.
“Later detection meant the consumer was denied the chance for earlier treatment. By the time the consumer’s lung cancer was identified, it was inoperable.”
She recommended the radiologist apologise to the patient, the Medical Council of New Zealand to consider his fitness to practise should he return to work, and consider if a review of his competence was required.
The radiologist would be referred to the Director of Proceedings to determine whether legal proceedings should be taken.
Caldwell considered the errors to be individual and cleared the district health board of any breach of the code.
