A 70-year-old woman’s breathing sounded like a “lawnmower engine” yet there was not a nurse in sight in the hours before she died at a residential aged care home in Sydney, a royal commission has heard.

The aged care inquiry on Monday examined the quality and safety of care given to the woman – known as DE – who lived in the Bupa Willoughby facility for one month before she died.

DE’s daughter told the royal commission in Sydney that she found her mother alone in her room and fighting to breathe before she died in August 2017.

“We walked in the corridor and it sounded like there was an engine or a truck or a lawnmower engine running,” she said on Monday.

“No one was with mum, she was in her bed and I can only describe it as someone who had run a marathon and couldn’t catch their breath.”

The daughter told the inquiry she was “frantically” running about the nursing home looking for staff. It took up to half an hour for anyone to come to her mother’s room.

When the after-hours doctor arrived, she said, he was in the room for “less than one minute”.

When she asked the doctor what was happening, he said: “This isn’t really my area of expertise.” He then walked out, the commission heard. DE died later that night.

When she first moved into the Willoughby facility, DE had to be fed by staff and supervised because she had difficulty swallowing food.

In one incident, DE was admitted to hospital and paramedics found unchewed food and medication in her mouth, the commission was told.

The daughter told the hearing she noticed her mother getting thinner and trays of untouched food being left in front of her.

“We knew the appetite was there, one day she devoured three cups of ice cream,” she said. “Every time we would go, mum’s face was more sunken and she was becoming a lot more unwell.”

Bupa Aged Care’s executive clinical director, Maureen Berry, told the commission on Wednesday the “right care” was given to DE “most of the time”.

Berry admitted she expected staff feeding DE to make sure the 70-year-old had swallowed her food and cleared her mouth.

The commission heard that staff at the aged care home stopped using a pain scale to help determine how much pain DE was in on July 22. “Someone stopped doing it,” Berry said, conceding that was a “serious failure”.