"I determine that the emergency care afforded to Russo fell short of best practice and resulted in a reduced prospect of her surviving and as such amounted to circumstances constituting a contributing factor in her death," Robb said.
The emergency started on February 17, 2012. As a diabetic, Russo's blood-sugar levels were checked each morning at 6am, and it was shortly before this time on February 17 that registered nurse Michelle De Leon checked in on her.
Finding Russo unresponsive, De Leon briefly set off an emergency bell to call for assistance before turning it off and going to the nurse's station to retrieve a patient file on Russo, Robb said.
De Leon then returned to Russo's room and initiated CPR before stopping it to make a 111 emergency call 10 minutes after she first set off the alarm.
De Leon argued she had continued CPR during the call but Robb said it was more likely she had stopped because CPR was a strenuous activity and he could not hear evidence of De Leon straining in the call's recording.
Robb said it was preferable to perform CPR on hard, flat surfaces and was critical of how De Leon administered CPR to Russo while she was in her bed, rather than arranging for her to be transferred to the floor.
He said CPR should have been undertaken from the moment Russo was found unresponsive and continued until ambulance staff arrived.
He was further critical of how De Leon's call to 111 did not "portray urgency".
As a result, the paramedics' arrival was delayed because they did not drive to Trevellyn under flashing lights.
When they did arrive, they were further delayed by about 10 minutes when they could not gain entry into the rest home, Robb said.
He said the rest home staff should have worked as a team to ensure the paramedics were given immediate access to Russo.
As a result of the incident, Robb recommended all Trevellyn's nursing and healthcare assistant staff undertake training in real-life emergency situations and working as a team.
This should include practising how to correctly convey information on 111 emergency calls and understanding the need to start CPR immediately, perform it on a hard and flat surface and continue it until paramedics arrive.
He said Trevellyn had advised him that they had already started ongoing training in these areas.