EMERGENCY departments in the western suburbs are struggling to cope with demand as Western Health predicts its patient numbers will rise rapidly over the next few years.

The 2008-09 Western Health annual report, released last week, shows 118,130 people turned up to be treated at Footscray, Sunshine or Williamstown emergency departments last financial year.

While all category 1 patients received immediate attention, 629 patients were stuck in the emergency departments at Footscray or Sunshine for more than 24 hours. This compares to 388 patients found in that situation the previous financial year - a 60per cent increase.

The time that Western and Sunshine hospitals spent on bypass also increased from 2.2 per cent to 2.8 per cent. (This is when ambulances are diverted from emergency departments that are under pressure, unless the patient's condition is critical.)

Western Health chief executive Kathryn Cook said: "This winter we treated about 3000 additional emergency department patients during the peak of the H1N1 human swine influenza outbreak. This put additional pressure on our three emergency departments and their overall performance."

Board chairman Ralph Willis said Western Health recognised the health care needs of the region would grow faster than anticipated.

"The western suburbs population is expected to expand by an extra 365,000 people over the next 15 years - a population greater than that of Canberra. We are working on facilities and workforce strategies to meet this growth in demand." He said expanding the service's capital infrastructure would be critical in meeting the demand.

"Next year we anticipate receiving further funding to build a new in-patient and ambulatory care building at Sunshine. The new facility will include 128 multi-day beds, 30 same-day oncology and medical chairs for cancer and other treatments, and specialist services."

The 2008-09 annual report shows 88per cent of category 2 patients were treated at Western Health emergency departments within 10 minutes and 75per cent of category 3 patients within 30 minutes, while 3219 people were on the elective surgery waiting list, compared to 2795 the previous year.