Surgery was also becoming more complex and patients were spending longer in theatre as procedures became less invasive, but took more time, the hospital advisory committee heard yesterday.
Jean-Claude Theis, who is also associate professor of orthopaedic surgery, said he had worked in hospitals overseas where surgeons finished operating on one patient and went straight to another theatre to begin operating on the next patient, who was already draped and anaesthetised.
However, in Dunedin there was down time between operations as the operating theatre was used to anaesthetise patients and set up surgical equipment.
Modern theatres had set-up and anaesthetic rooms attached to them, which saved time between operations.
Prof Theis said he could do about three hip replacements a day, but with a more efficient system he could probably do about five.
"We are really limited by the layout and number of theatres, and staff as well, of course."
Committee member Louise Carr asked if it had been worked out how quickly money spent on upgrading theatres could be recovered in efficiency savings.
Chief medical officer Richard Bunton said there would be significant increased costs to achieve such efficiencies, as not only would more infrastructure be needed, but more nursing and anaesthetic staff and "our current funding model does not allow for that".
Committee member Susie Johnstone said there "must be some tipping point where the numbers stack up".
Prof Theis said elective surgery rates were also affected by acute, or urgent, surgery lists becoming "unmanageable", forcing elective surgery cancellations.
Some hospitals kept acute surgery "completely separate" from elective surgery, but he was not sure if Dunedin Hospital was big enough for that to be an option.
Less invasive procedures were often more time consuming and more theatre time was being used to do less work, he said.
Mr Bunton gave the example of taking out a person's appendix, which used to take about 20 minutes when he was a registrar, but now took about three hours with a laparoscope.
Better access to elective surgery is one of six health targets Health Minister Tony Ryall is demanding of district health boards.
