A service engineer who had surgery for obstructive sleep apnoea at the National University Hospital (NUH) was pronounced brain dead two weeks later.
An inquest into the death of Singapore permanent resident Yeow Mun Wai, 38, heard that he had elected to undergo palate surgery with removal of his palatine and lingual tonsils on April 21 last year due to worsening choking sensations during sleep.
He had a moderate degree of obstructive sleep apnoea.
Dr Ong Yew Kwang, senior consultant, otolaryngology, head and neck surgery, testified on Monday that he had performed 15 such operations at NUH and Mr Yeow's was the first fatality.
Mr Yeow saw Dr Ong in March last year, 21/2 years after the doctor had performed surgery on his nose at NUH to relieve nasal obstruction.
Mr Yeow was still bothered by his condition which was attributed to the narrowing of his upper airway in the throat by the palatine tonsils and prominent lingual tonsils at the tongue base.
Despite explaining the risks of bleeding and swelling of the airway to him, Mr Yeow opted for surgery rather than continuous positive airway pressure, or CPAP, therapy.
Tongue-base surgery was performed on April 21 to remove his uvula and for shortening of the soft palate. Upon completion, the wound bed was checked and no bleeding was evident.
Mr Yeow was at the surgical intensive care unit the next day when he told his wife, Madam Teoh Lay Sim, 37, that he had "vomited a large quantity of blood" and his throat still hurt. She told him to inform the doctor. She also told a nurse about the development.
Dr Ong testified that the coffee-coloured material vomited would have been the residual fluid that had accumulated from the initial surgery, and was not fresh bleeding.
Two days later, Mr Yeow coughed up blood and suffered a cardiorespiratory collapse.
Code Blue was activated and his pulse returned after about 30 minutes of resuscitation. By then, the court heard that he had begun to show signs of hypoxic ischaemic encephalopathy - lack of oxygen and blood flowing to the brain - which eventually caused his death.
Mr Yeow was noted to have a bleeding vessel from the left side of the tongue base wound. A procedure was performed to stanch it.
He was intubated and returned to the surgical intensive care unit where he was pronounced brain dead on May 5.
After a close review of his case, NUH will now implement measures, including a preventive tracheostomy (an opening surgically created through the neck into the windpipe), to allow diversion of any sudden bleeding from such procedures.
Finding Mr Yeow's death to be a tragic medical misadventure yesterday, State Coroner Marvin Bay said perhaps the most apt lesson to draw would be that treatment choices should always be collaboratively explored between doctor and patient.
Patients must be made aware that the choice to undergo any invasive surgical procedure may not be free of risk.
Madam Teoh said that although she had asked her husband to seek a second opinion in Johor Baru where they lived, he declined as he trusted Dr Ong.
State Counsel Stella Tan Wei Ling assisted the court in the inquiry.