PATIENTS faced lengthy waits, relatives had to wait outside because corridors were full of trolleys, and ambulance crews were delayed for up to two hours during one of the Royal Gwent Hospital emergency department's busiest nights of the year.

At one stage on Monday evening, there were nine ambulances and two rapid response vehicles parked outside the department, with not enough bays to contain them - a scene photographed by a patient's relative.

Her brother had been injured in a road accident in Caerleon, and after treatment at the scene by paramedics, arrived by ambulance around 7pm.

"There were five or six ambulances when we got there, but by about 9.30pm there were nine and a couple of response cars," said the woman, who did not wish to be named.

"There were no proper spaces left, it was so busy.

"My brother came off his motorbike and they suspected he'd broken a leg and an arm - and there were eight or nine patients on trolleys.

"It was so busy at one point, relatives or friends were asked to wait outside because the corridors were jam-packed."

The woman's brother was later confirmed with a broken arm and ligament damage to a leg, and was able to go home at around 1.30am yesterday morning.

"There were people who had a long time, and ambulance crews who had been there a couple of hours because of delays handing over patients," said the woman.

"One told me his shift should have finished at half past seven and he was still there at 10.

"The crew who dealt with my brother were brilliant and I just think it's wrong that the ambulance service gets criticised all the time when there are delays like that at hospitals."

Though figures are not available, an Aneurin Bevan University Health Board spokesman said Monday night was among the busiest of the year for emergency departments, not only in Gwent but across the region, and the emergency department was busy again yesterday.

"The picture appears to have been much the same across South Wales, with reports from WAST (the Welsh Ambulance Services NHS Trust) that it was their busiest day since the New Year," he said.

"There was a high volume of ambulance crews bringing in very poorly patients throughout the day.

"The (emergency) department at the Royal Gwent Hospital has remained busy, and we wish to apologise to any patient who has experienced a long wait for treatment."

Predicting peaks and troughs of demand, and staffing A&E units appropriately, is an inexact science, and there remain occasions on which demand outstrips capacity.

The target of dealing with at least 95 per cent of attenders inside four hours remains challenging and elusive across Wales, though figures show that performance at Gwent units was the best in Wales for much of the first four months of 2014.

Much improvement remains to be made however, on ambulance handover times, and to eliminate A&E waits of longer than 12 hours.