A new report has revealed a serious deterioration in emergency department overcrowding at a number of major hospitals around the country.

The biggest increase in trolley patient numbers recorded last year was at Tallaght Hospital, where numbers more than doubled in nine months. The report shows a major deterioration in the ED situation at Tallaght and three other hospitals from the spring of 2013.

And the report had identified poor systems management, in addition to increased patient volume and reduced capacity, as factors behind the ED crisis in some hospitals.

A report from the HSE's Special Delivery Unit has shown what while there was an overall decrease nationally in 2013 in the number of emergency patients waiting on trolleys for bed accommodation, the situation actually worsened in some individual hospitals.

The report says there was a significant performance deterioration in terms of ED patient management at Beaumont Hospital; Cork University Hospital (CUH); Tallaght Hospital and Waterford Regional Hospital.

At Beaumont, the report says there was a significant high volume of ED patients waiting on trolleys throughout 2013, with an average daily trolley count of 23. The hospital recorded a 30% increase in trolley numbers in the second half of 2013 compared to the same period in 2012.

The main factors behind the trolley crisis at Beaumont included delayed discharge patients awaiting alternative community accommodation.

At CUH, there was a 54% increase in trolley patients in the second half of 2013 compared to the same period in 2012. Factors behind this increase included rising patient numbers and less than optimal patient processing and discharge, according to the report.

At Tallaght Hospital, a massive 145% increase in trolley patient numbers was recorded from March to December 2013 compared to the same period in 2012.

Factors behind the overcrowding at Tallaght included less than optimal patient processing and less than optimal usage of the acute medical unit to take pressure off the emergency department, the report said.

At Waterford Regional, there was a 51% increase in trolley patients from March to December 2013 compared to March to December the previous year.

Factors behind the ED pressure at Waterford included 'less than optimal operational control and patient pathway progression', and limited surgical bed capacity.

The report shows there was a 24% reduction in national trolley numbers between 2011 and 2012 and 14% reduction last year

The report notes an improved ED performance by a number of hospitals last year, including Our Lady of Lourdes in Drogheda. However, Lourdes Hospital had 57 emergency patients awaiting an inpatient bed earlier this week.

The four hospitals identified as having a worsening trolley crisis in 2013 have continued to suffer ED trolley problems into 2014.