Whanganui's DHB refused to comment on the matter.
In the lead-up to the strike that was withdrawn, the Whanganui DHB did say it would delay non-urgent surgeries to manage demand on the day of the strike.
About 84 per cent of the DHB's 560 nurses, midwives and healthcare assistants are members of the NZNO.
The chief executive of the Whanganui Regional Health Network, Judith Macdonald, said the decision from nurses to strike came as a bit of a surprise to her.
She said it was likely non-urgent care would be put on hold for the day.
"The planning for strike starts long before the actual event so contingencies will already be in place to stop those services that can be, like elective surgery," she said.
"The strike is limited to DHB nurses so the primary care nurses will be working business as usual.
"For primary care we generally experience a quiet day on the actual strike day and then services get very busy for the following days."
Macdonald was confident there would be life preserving services still in operation at the hospital and the ambulance service would be unaffected.