An orthopaedic surgeon says measures introduced to improve the trolley crisis have had a detrimental impact on waiting lists.

Yesterday it emerged almost half a million adults and children around the country are waiting for hospital procedures.

Peter O'Rourke (pictured), a surgeon in Letterkenny Hospital in Donegal, said theatre lists were being put on hold to free up beds for people in emergency departments.

He said nobody considered the impact of the so-called escalation policy to help tackle the trolley crisis.

"The whole emergency department (and) trolley crisis gets knee-jerk reactions," he said.

"You read 500 people are on trolleys and nurses in emergency departments are threatening to go on strike (and) a deal was done to appease the emergency departments' staff because of all the people on trolleys, but the consequences were not looked at," he said.

"I don't know if anyone working inside the hospital (but) outside of the emergency departments had any input into this policy."