SINGAPORE - The state coroner has called for stricter procedural safeguards when patients dependent on ventilation equipment are moved from one place to another, following a "medical misadventure" that led to the death of an elderly patient a year ago.

These include closely monitoring the patient and devices tracking his vital signs when he is placed on the equipment, instead of other "subsidiary" tasks, and retesting the machine on-site beforehand.

Neither had been done before Madam Ramasamy Krishnama, 83, went unresponsive while being transferred to Mount Elizabeth Novena hospital on the evening of July 8 last year.

Shortly after being moved from her Tan Tock Seng Hospital bed to an adjacent trolley and put on a portable ventilator, her level of oxygen saturation became "unrecordable" because a transfer team had failed to turn on an oxygen tank that was supplying the ventilator.

But the team first checked for other problems, as they assumed the tank had been switched on after hearing a gushing sound when the two pieces of equipment were connected.

Three to four minutes had passed before they realised this and flipped the switch.

Madam Ramasamy's condition did not improve even after the ventilator was turned to the maximum setting. She was moved back to her bed, where cardiopulmonary resuscitation was unsuccessfully attempted on her.

She died from lack of oxygen to the brain later that evening.

On Wednesday, State Coroner Marvin Bay found that the grandmother's death had been caused by a failure to ensure she received sufficient ventilation.

No foul play is suspected.

Coroner Bay said that patients in Madam Ramasamy's situation would be too frail to say or gesture if they were in distress.

"They are therefore utterly dependent on the vigilance of the doctors and nurses of the transfer teams to spot if anything is amiss," he said.