The way Dr Sean Ng Yung Chuan treated a patient who died following total knee replacement "goes beyond mere human error", said the coroner at the conclusion of a seven-day hearing.
State Coroner Kamala Ponnampalam said on Monday (Sept 16) that a coroner "does not make a determination of guilt or negligence or attribute legal or moral culpability".
Nevertheless, she flagged Dr Ng's behaviour which "demonstrated a clear departure from the standards expected of a physician who had primary care of a post-surgery patient".
She criticised the doctor for failing to make detailed notes or to hand the patient over to another specialist when he had planned to travel after operating on her. If he had done so, the other specialist might have noticed tell-tale signs that something was wrong, and taken action earlier.
Dr Ng, who has been a practising orthopaedic surgeon since 2011, said he had told Mrs Yuen about the conference in Tokyo and had suggested performing the surgery upon his return.
“According to Dr Sean Ng, Mrs Yuen was quite insistent on having the surgery done before his departure but did not say why,” the coroner recorded.
Dr Ng said that prior to his departure, he had checked how Mrs Yuen was progressing and was told “everything was fine”. He said it was not mentioned to him that her lower left limb was cold.
Dr Ng said that while he was in Tokyo, ward nurses told him Mrs Yuen complained of leg numbness and he called the anesthetist who assisted him on the knee replacement surgery Dr Adrian Ng to review her. Dr Adrian Ng told him to continue with his trip, Dr Ng said.
When the elderly woman’s condition worsened, the surgeon said he cut his trip short and returned to Singapore on Nov 5, 2016.
“Dr Sean Ng stated that he did not hand over care of Mrs Yuen to another specialist during his absence because there were no post-surgical complications prior to his departure and her progress was acceptable,” the coroner wrote in her findings.
“He added that he was unable to comment if there would have been a significant difference to life and death if the vascular damage had been identified and managed intra-operatively.”
In addition, Ms Ponnampalam found that Dr Ng had documented his reviews of Mrs Yuen's condition retrospectively in the case notes, instead of at the time of the reviews on Nov 1, 2016 and Nov 2, 2016.
"The making of retrospective case notes is a clear contravention of SMC guidelines," the coroner wrote.
According to the coroner’s report, the hospital also had concerns about the nurses who cared for the patient, with one being given a “verbal warning” for having documented circulation as normal in the care pathway chart when she did not personally assess the patient.
In her conclusion, Ms Ponnampalam said the evidence showed that an artery and vein were likely transected during the initial knee replacement operation conducted by Dr Ng, and that although a “relatively rare complication”, it was a known risk and should have been accounted for during the surgical approach.
Ms Ponnampalam also said: “Dr Sean Ng leaving the country on post-operative day two after performing a major surgery with a failure to hand over the patient’s care to an appropriate specialist was injudicious and may have resulted in the delayed recognition of the ischaemic limb.”
“The decision not to arrange for a covering specialist during his absence was short-sighted,” she said.
The coroner also said that the documentation of Mrs Yuen’s post-surgery care was “less than ideal” and “found to be unreliable” by the medical expert.
There was a “dire lack of details” in Dr Ng’s notes and that the retrospective entries days after were “unhelpful” as the patient’s condition had “severely deteriorated”.
The nurses’ notes were also “brief and in some instances, inaccurate”, and one nurse had relied on Dr Ng’s observations instead of making independent checks.
Ms Ponnampalam noted that an inquiry is not meant to make a determination of guilt or negligence, but it does assess "if an act has fallen short of reasonable standards".
She said there was no basis to suspect foul play.
A scan found that severed blood vessels had caused an ischaemic limb, which is a lack of blood flow to a limb.
An emergency operation was conducted successfully but Mrs Yuen continued to deteriorate. Dr Chin decided on emergency high above knee amputation to save her life but post-surgery, Mrs Yuen went into cardiac arrest and developed multi-organ failure.