For some patients it will be "considerable weeks" before they head off again for surgery, she said.
"It isn't like a one-off event where we can plan the resumption - we need to continue to monitor it and ensure we a delivering acute services first."
She said patients will be kept informed and all affected patients had been contacted directly by phone, text or letter.
Aitcheson said with roughly 80 per cent of junior doctors striking, senior doctors were being called in to work extra shifts over the 48-hour period.
A Waitemata DHB spokesman, who was speaking on behalf of all Auckland DHBs, said he did not know exactly how many surgeries in the region were impacted as they were still working through it.
"That information isn't available to us yet but patients affected will be kept informed," he said.
Auckland District Health Board spokeswoman said the DHB promised patient safety would remain a priority but non-urgent and non-acute services have been rescheduled.
"Patients should still come to their scheduled appointment or surgery on the strike days unless we have contacted them directly to say their appointment is being rescheduled," a Auckland DHB spokeswoman said.
The DHB will continue to provide emergency and life-preserving services throughout the strikes - this includes all acute services and some cancer treatments.
Dr Michael Roberts, chief medical officer at Northland DHB, said people could help take the pressure off emergency services by always making their general practice team the first port of call for their health-care needs.
"Our emergency departments will remain open throughout, and you shouldn't hesitate to dial 111 in a life-threatening emergency."
For most other health care, patients were advised to call their own general practice team first, or call Healthline on 0800 611 116.
Calls to Healthline are answered by registered nurses who provide free health advice after hours and, if urgent, will advise where to go.
Union, Resident Doctors' Association, said their members were striking to keep the terms and conditions in their collective contract that prevents them from working 16 hours in a row without guaranteed breaks.
Following MECA (Multi-Employer Collective Agreement) negotiations, the union's senior advocate David Munro says RMOs could also be moved to any hospital in the country as the DHBs see fit.
"RMOs could lose access to education and training, jeopardising the quality of care we are
able to deliver to our patients, and a whole lot more," Munro said.
However, DHBs say they "strongly dispute" these claims.
DHB spokesman Dr Peter Bramley said it was untrue for the union to say they wanted to move junior doctors around the country at will.
"Rosters across multiple hospitals in non-urban areas and any combined duty and on-call period of more than 16 consecutive hours currently requires the approval of the RDA.''
He said DHBs would prefer affected employees make decisions about rosters locally, rather than the union.
"DHBs are committed to being good employers supporting safe care and safe working conditions,'' he said.
All you need to know:
Why are junior doctors striking?
Following MECA (Multi-Employer Collective Agreement) negotiations, RDA members say they are disputing "clawbacks" to their terms and conditions. The union says as part of the new collective agreement junior doctors could be moved to any hospital in the country as the DHBs see fit, they could work 16 hours in a row and they could lose access to education and training. However, DHBs "strongly dispute" these claims.
How many are striking?
Around 3300 DHB-employed junior doctors are striking for 48 hours from 7am today.
What happens next?
Mediation between DHBs and the union will continue but a second strike action is planned for 48 hours on January 29 and 30, unless an agreement is meet.
Any concerns who should patients contact?
Unless urgent, patients were advised to call their own general practice team first or call Healthline on 0800 611 116. If urgent, call 111.
