The DHB said Hawke's Bay Hospital would provide essential and urgent services including emergency departments, acute surgery, intensive care, cancer treatments, maternity services and acute wards at reduced capacity.
Wairoa Hospital would provide ED services for essential and urgent cases.
The Central Hawke's Bay Health Centre inpatient ward would be closed.
General practices and most other health services across the region would not be directly affected.
Hawke's Bay Hospital chief executive Kevin Snee thanked staff, the contingency planning team, general practice and other health providers for the support they were offering to the DHB.
"We apologise to our patients whose operation or appointment will have to be deferred and we will rebook them as soon as we can."
The strike comes after NZNO members voted to reject the latest DHB Nursing and Midwifery Multi-Employer Collective Agreement offer.
Industrial services manager Cee Payne confirmed that industrial action would go ahead this Thursday and continue until early Friday morning.
Nationwide, at least 30,000 NZNO members were involved.
Many staff covered by the DHB MECA agreed to provide life-preserving services during the strike.
"Life-preserving services and contingency plans are coming to completion with the 20 district health boards. We are confident that these will be in place as patient safety and public safety is paramount."
DHBs requested a reconvening of facilitation and Payne said the NZNO had an obligation to respond without knowing the outcome of the ballot.
"In response we have stated that the unavailability of additional funding to support an improved offer has led NZNO to the conclusion that facilitation is not the appropriate forum to address the current difficulties in the DHB/NZNO MECA at this time.
"The issues faced and reported by our members have arisen from a decade of severe underfunding of our public hospitals which have failed to keep pace with growing community need, the ageing population and workforce, and increased costs."
In case of emergencies during the strike, patients should go to the Emergency Department. For non-emergencies people should to contact their GP or urgent doctors.
Healthline 0800 611 116 would continue to be available for medical advice as well as 111 for emergencies.
