Resident doctors and their DHB bosses will be back at the negotiation table on Thursday.
A planned 48-hour strike will go ahead next Tuesday after failing to reach a settlement. It will be the second round of industrial action this month.
Junior doctors say they're sick of being rostered on for 16 hours a day, sometimes more than 10 days in a row.
The Resident Doctors' Association says any realistic opportunity to resolve the dispute ahead of the industrial action is something they must pursue.
Canterbury DHB says it is "well advanced in its contingency planning to ensure it continues to provide safe care during the strike period".
"We are prioritising essential and acute services, which means that some outpatient appointments and planned surgeries are being rescheduled," said chief people officer Michael Frampton.
"We will be re-booking those affected to the next available appointment."
The emergency department at Christchurch Hospital will remain open.
Patients who want to check if their scheduled appointments have been cancelled should call 0800 778 226.
An outcome on the mediation is expected later on Thursday.