A record number of patients visited NSW public hospital emergency depts in the quarter to March, the AMA is calling for the federal govt to reverse cuts.

NSW hospital staff have "reached the limits" of efficiency and need the federal government to reverse funding cuts, Australian Medical Association says.

According new Bureau of Health Information figures released on Wednesday, more patients arrived at the NSW public hospital emergency wards than ever before in the quarter to March 2016.

More than 672,000 patients visited the emergency department over the quarter, up four per cent on the previous year.

Wait times and admissions also spiked, while the number of patients leaving emergency departments within four hours fell slightly to 74 per cent.

"The BHI report shows that while NSW hospitals had been holding the line, and even improving up until recently, they're starting to slip backwards," AMA NSW president Brad Frankum said.

"Even though on-time treatment in emergency has remained stable, there has been a dip in performance against the four-hour rule."

Some 97 per cent of patients received their elective surgeries within clinically recommended timeframes, a dip of one per cent.

The number of emergency services performed over the quarter dropped to 49,000, while the amount of elective surgeries performed on time also slipped.

Professor Frankum said substantial cuts to health funding from the federal government would make a bad situation worse.

"NSW hospitals are already slipping backwards in the face of unprecedented demand for health services," he said.

"The doctors, nurses, and allied health staff have reached the limit of the amazing work they have done in finding efficiencies.

"The future of health will be longer waiting times and poorer patient outcomes unless the federal government reverses its funding cuts."

Despite the increased demand for hospital services, 91 per cent of patients arriving by ambulance were transferred to emergency staff within 30 minutes.

Health Minister Jillian Skinner said hospitals were performing at a high standard despite the enlarged patient load.

"Nowhere is the incredible work of our doctors, nurses and hospital staff more evident than in NSW emergency departments, where presentations have increased steadily year on year over the last five years," Mrs Skinner said in a statement on Wednesday.