''In the ENT service, we have made hard decisions to return patients to the GP untreated.
''Currently, more than 25% of patients assessed who would clinically benefit from surgery are returned to the GP, as we are unable to provide surgery within the four-month period.''
The letter reveals the service is on ''probation'' with the Royal Australasian College of Surgeons, the body responsible for training accreditation.
The department will be inspected by the college early next week and could lose one of its trainee positions, Mr Fields' letter warns.
''If we are unable to show a significant increase in the appropriate types of surgical experience, we will lose one of our trainee positions.
''If we lose a position, it will be very difficult to provide on-call cover and staff to travel to Invercargill as they will need to be in Dunedin to cover calls.
''This will have a significant impact on our ability to provide a service, attract and train junior and senior staff [myself included].''
Mr Fields said the patients denied surgery had attended a pre-admission clinic and made arrangements for their stay in hospital.
''To then be told that they were being cancelled at that stage for elective cases from another service, just because they have been waiting a long time, is unreasonable.
''If it was for a more urgent cancer or airway case within our service, it is still not ideal, but more acceptable,'' Mr Fields said. The ENT department was effectively penalised for sticking to the four-month rule, he said.
''If we did not do this, then we might have more leverage to get more access to theatre.
''It seems a perverse incentive to penalise those services that have made the effort to comply by removing more of their operating [time].
''The SDHB are now paying two surgeons to do nothing for four hours on a Monday morning.''
The service was experiencing increased demand for skin cancer surgery because of the ageing population.
In her response to Mr Fields, which was also released under the OIA, Ms Heatly said the urology cases had to be done by the end of March, and the day in question was the only day they could be done.
Alternative arrangements had been made for affected patients, Ms Heatly said.
Dunedin GP Dr Phil White said the situation in ENT and some other specialties was placing more burden on GPs and patients were suffering.
''We're seeing people who are struggling with daily life because they can't be seen or have their operation,'' Dr White said.
''There's certainly more suffering in the community because of it.''
''Anything that's not cancerous'' was frequently turned away from ENT; sinus problems, recurrent childhood tonsilitis, and glue ear were examples.
''Certainly, ENT is one of the departments that seem not to be coping with the demand for [specialist] appointments and for surgery.''
Yesterday, the board's surgical directorate medical director, Stephen Packer, said the board treated the most urgent patients first, which included those who had waited for longer periods of time.
''Our ENT department is working very well and, thanks to the efforts of that team, patients who meet the criteria receive surgery when they need it,'' he said.
The Ministry of Health is working on a project to measure the ''unmet need'' created when patients are turned away without treatment.
At present, the level of unmet need is not quantified.
• Are you affected by the overloading of the ENT department at Dunedin Hospital? Contact eileen.goodwin@odt.co.nz