The Nurses Union says it has been warning severe staff shortages have affected patient safety at hospitals long before a woman died after leaving Middlemore's Emergency Department because of long wait times.
The woman left the hospital in the early hours of Wednesday morning, after being told it would be hours before she could be seen by a doctor.
She soon returned and later died in intensive care.
Nurses Organisation president Anne Daniels told Morning Report health workers were aware staff shortages could cause a death.
Daniels says it has become impossible to keep everyone safe in hospitals.
