PATIENTS admitted to intensive care units in Scotland are more likely to survive than ever before, but auditors have warned that bed shortages at some hospitals are driving clinicians to discharge patients too early.

A report on critical care found higher than average rates of early discharge at the intensive care units in the Royal Infirmary of Edinburgh and the Inverclyde Royal Hospital in Greenock.

Early discharge is defined as “a transfer that is not in the best interest of a patient but necessary due to pressure on beds or staffing”.

In Scotland as a whole, two per cent of discharges from intensive care and combined ICU-high-dependency units were classed as “early” in 2016. But this rose to just over 13 per cent at Inverclyde Royal and just over 12 per cent at Edinburgh’s Royal Infirmary. The discrepancy was only considered to be statistically significant in the case of the Royal Infirmary - which handled nearly 13 times as many patients - but both hospitals were advised to “reflect carefully” on the findings.

The Audit of Critical Care in Scotland report states: “For [the Royal Infirmary of Edinburgh] ICU in 2016 the reason given for the vast majority of the early discharges was ‘shortage of beds’. This is consistent with the rest of Scotland as the main reason recorded for early discharges.

"High rates of early discharges are a concern as they reflect a discharge that is felt by the clinical team not to be in the patient’s best interest. This is usually due to underlying pressure of beds or staff reflecting a lack of available resource.

“[Inverclyde Royal Infirmary] ICU and [Royal Infirmary of Edinburgh] ICU have rates of more than 10 per cent while in the overwhelming majority of units the early discharge rate is very low at less than five per cent. While this is only statistically significant in [the Royal Infirmary of Edinburgh] unit, both units should reflect carefully on this data.”

Tracey Gillies, Medical Director for NHS Lothian said that most of the the patients discharged early from ICU had in fact been moved to the High Dependency Unit where they continued to receive critical care. She added: "The Royal Infirmary Edinburgh’s Intensive Care Unit has the highest number of night time admissions and it is sometimes necessary to move patients at night so that we can safely treat incoming patients - we are implementing changes to reduce night-time discharges, including expanding our bed capacity."

A spokeswoman for NHS Greater Glasgow and Clyde said: "The ICU beds in Inverclyde Royal Hospital are part of a combined critical care unit, encompassing HDU and CCU level 2 care and these patients are stepped down into these adjacent beds under the care of the same medical and nursing teams but only when it is safe to do so."

The annual report is believed to be the most detailed audit of critical care in the world. Overall, the report found an "encouraging" fall in mortality among patients admitted to intensive care, from 20 per cent in 2007 to 13 per cent.

It said: “There has been a continued small but steady improvement in the number of patients surviving ICU in Scotland. However, there are still challenges. The changing pattern of health service provision and increased ward bed utilization means that limited critical care beds are occupied by ward level patients, and that more patients are discharged out of hours. This has implications for both emergency patients and planned admissions (usually for elective surgery).”

Peter Bennie, chair of BMA Scotland, said: “It is good to see that there has been a small but steady improvement in the survival rates of patients admitted to ICU in Scotland.

"However the report on critical care also highlights the pressures that the system is under; above average levels of early discharges at some hospitals blamed on bed shortages; high rates of delayed discharges resulting in many occasions when vital critical care resources are tied up unnecessarily, while other patients may have care delayed.

"When resources are stretched in this way it affects the ability of units to plan effectively- this is bad news for patient care.

“On average 25 per cent of admissions to ICU and HDU occurred at night. This demonstrates the demand on these services to provide emergency care out of hours. Discharges at night were also occurring in both ICU and HDU.

"With rising demand across the NHS in Scotland steps must be taken to ensure adequate funding and resources are in place to meet the needs of our sickest and most badly injured patients, and reduce the pressure on units delivering such vital services"

It comes as Scotland's emergency departments met the waiting times target during the final week of July, with 95.5 per cent of A&E patients seen and either admitted, transferred or discharged within four hours. The figure is up slightly from 95.3 per cent the previous week.