The nurse was due to be discharged today after being treated for a non-life threatening stab wound.
The patient was arrested and taken into custody by Counties Manukau police.
Ms Young said a review into the incident had been launched.
Counties Manukau District Command Centre Senior Sergeant Miles Horsnell said police were called to a property on Brady Rd, Otahuhu yesterday evening.
"Following an incident there, we have arrested a 25-year-old male who has been charged and will be appearing at the Manukau District Court tomorrow.
"He's been held in custody. He's been charged with wounding with intent to cause grievous bodily harm."
Police carried out a scene examination at the property during which several objects were taken, Mr Horsnell said.