A major incident declared at the hospital on Monday remains in force.
A meeting of the North Staffordshire Clinical Commissioning Group (CCG) heard almost all planned surgery had been cancelled.
The hospital said as well as increased demand at A&E, it had struggled to free up beds due to an outbreak of norovirus and flu.
Sally Parkin, clinical director at the CCG, said: "There are 91 cases of flu at the moment in the hospital and we have to keep patients safe, so we have to have areas that are separately nursed for patients with infections illnesses
"So at the moment we just don't have enough bed capacity for those patients and that's why we've got a bottleneck in A&E."
She said while the Royal Stoke A&E  was "very busy", patients were being cared for and dealt with in a "calm and systematic way".
Last week, the University Hospitals of the North Midlands trust, which runs the Stoke Royal recorded the worst A&E figures in England, with just 61.3% of patients seen within four hours, compared with a national target of 95%.
Almost 150 people have waited more than 12 hours on trolleys at Royal Stoke University Hospital in the last week.