But Waitaki District Health Services chief executive Ruth Kibble said not all 22 staff had left because of the changes taking place.
Four had retired, 10 had left the district and one finished a fixed-term contract, she said.
Mrs Kibble backed the change under way at the hospital, and in response to Waitaki Community Hospital Action Group claims this week that the staffing situation was increasingly unsustainable she invited the Otago Daily Times to sit down with six of her staff this week.
Those staff members said while it had been an emotional time, the hospital was striving to deliver improved services, and to be a better place to work.
Clinical director Dr Pragati Gautama said she had been shocked by the level of scrutiny the hospital had endured recently and it had been hard on the people who worked there.
"Oamaru is actually the last level 3 rural hospital to actually start addressing rural health the way places like Dunstan, Queenstown, Kaitaia, Greymouth, Gore, Balclutha [have] - we're the last hospital to really embrace that change," she said. "And we need to get on board with that."
Nursing director Yvonne Thomas said as staff left there had been periods recently when there were "gaps in rosters", which had been stressful, but the hospital was now fully staffed with registered nurses.
Some stress for staff had also come with the challenge of "embracing new change and new practices".
The resignations had also been "really awful for some people", who grieved the loss of colleagues they had worked with for a long time.
"What [Dr Gautama] and I did, we made a contingency that when staffing became an issue ... we capped the bed numbers, we closed the HDU (high-dependency unit) and we said they'll have to go to Dunedin - and that was all in order to make sure the staffing remained safe," she said.
"That was during a time when we were recruiting and people had resigned or left.
"You've got to remember you're dealing with a culture where people have stayed for 30, 40 years, so anything slightly out of the norm is `this is totally unsafe'.
"We've actually got a really well-covered, experienced amount of staff here."
Clinical trainer Paul Brown, a registered nurse who has been in Oamaru for three months, said that the reaction to the changes under way had been "really emotional".
"There are some issues with safety here, but it is not life-threatening - there is no threat to the patient care, to patient safety, to staff safety. It is ... housekeeping stuff, but we're tightening it all in. At no time in the last three months have I seen unsafe practice, unsafe equipment, anything like that. It's all very emotive. And that's what I think the community is seeing."
Yesterday, Waitaki Community Hospital Action Group member Marcelane Ballantyne, a registered nurse, said she felt for staff at Oamaru Hospital.
She said the hospital's management had been putting nurses in unsafe situations as recently as the start of this month.
She also provided nursing rosters to back up her claims.
"If you were to work outside of your scope, for example, working in the emergency department without level 6 life support training, then you would be working outside your scope, which would put your practising certificate on the line," she said.
