An emergency doctor has admitted "cognitive bias" led to an Indigenous man being wrongly diagnosed with a drug-related condition, rather than the ruptured stomach ulcers that ultimately killed him.
Ricky Hampson Jr, 36, died from perforated duodenal ulcers on August 16, 2021, less than 24 hours after being discharged from Dubbo hospital, in western NSW.
The Kamilaroi-Dunghutti man went to the emergency department on August 14, telling staff he'd felt a popping or tearing sensation in his abdomen and was in "10 out of 10" pain.
An inquest is examining whether racism and bias were factors in a misdiagnosis of cannabinoid hyperemesis syndrome, which is seen in drug users and features vomiting and nausea.
The emergency medicine specialist who made the incorrect diagnosis told the inquest he first considered the syndrome when Mr Hampson Jr was brought to a bed in an agitated state and showing signs of pain.
The doctor, who cannot be named, said Mr Hampson Jr told him he smoked a small amount of cannabis that morning.
Blood test results showing Mr Hampson Jr's electrolytes were depleted, possibly through vomiting, supported the initial impression of the drug-related condition, the doctor said.
The inquest has been told Mr Hampson Jr did not report vomiting or nausea, key features of the syndrome.
The doctor said the misdiagnosis and the failure to order scans was a crucial mistake.
"It is a matter of deep regret," he told the inquest in Dubbo on Tuesday, followed by a long silence in the courtroom.
He said his decisions were the result of "cognitive bias", as he had seen other agitated patients with the condition and his brain was closed to alternatives.
While he had previously treated Indigenous people for the syndrome, the doctor denied that Mr Hampson Jr's race was a factor.
"It was just the brain recognising the pattern when the patient came in," he said.
He also denied knowing about Mr Hampson's description of a popping sensation, saying that information would have led to different treatment.
"One thing emergency physicians are scared of is someone saying they've got a popping feeling ... I would have remembered that information" he said.
Deputy State Coroner Erin Kennedy has been asked to consider whether Mr Hampson Jr's treatment was influenced by several elements of bias.
Along with his race and drug use, Mr Hampson Jr's records listed his next-of-kin as the governor of a jail he left the year before.
Dr Lisa Hu, who was a resident at the hospital and examined Mr Hampson Jr, said the senior doctor diagnosed the syndrome.
She acknowledged that CT scans and X-rays were available at the hospital, but had not been recommended.
Asked what she would have done differently, Dr Hu said: "I could have considered the differentials more, (been) more assertive ... and suggested some investigations."
The inquest continues.
