Intensive care services at one of Scotland's main children's hospitals risk becoming unsafe unless action is taken to address critically low staffing levels, a report has warned.
A review of heart surgery at Glasgow's Royal Hospital for Sick Children, also known as Yorkhill, found that more than half of the areas studied had a poor standard of service and one was classed as inadequate.
The experts who carried out the review said: "Of concern was a sense that the provision of paediatric intensive care may be unsafe if critical staffing problems are not addressed."
At the time the assessors visited the paediatric intensive care unit (PICU) at Yorkhill in November 2011 staffing problems in the PICU had been worsened by the departure of two consultants. So far only one of those posts has been filled.
The report said: "The panel was of the view that urgent remedial action is required in PICU to prevent care from becoming unsafe."
Even if the consultants were replaced, hospital staff acknowledged that "this may still leave the PICU stretched to a degree that may be unsafe", the experts noted.
Out of 31 areas of paediatric heart surgery reviewed, 19 were judged to be poor as well as one that was inadequate.
The report found that the three surgeons working at Yorkhill did not share the workload evenly, with one surgeon performing about 140 procedures during the year, roughly half the total.
The fact that the hospital only employed three surgeons itself "impeded an ability to deliver a safe surgical rota around the clock".
While there was a high degree of trust between patients and staff, patients and parents did not appear to be actively involved in decision making.
The experts were "left with an impression that the senior leadership team were not operating as a cohesive team and that there was a lack of clear strategic leadership".
The report also identified a "poor working relationship between members of the cardiology and surgical teams".
Dr Jim Beattie, associate medical director of women's and children's services at the health board, said "significant progress" had been made to address short-term staffing issues.
He said: "At the time of the review there were two consultant vacancies within the PICU. One of these posts has already been filled and we are working hard to recruit to the remaining post."
Dr Jennifer Armstrong, medical director of NHS Greater Glasgow and Clyde, said the review "confirmed many areas of good practice as well as highlighted areas where we need to improve".
She said that a recent audit showed that the outcomes for children at the unit were "among the very best in the UK".
She said: "I am satisfied that the service we provide is both safe and sustainable."
Scotland's chief medical officer Sir Harry Burns praised the "excellent children's cardiac service" and said the outcomes for patients there were "as good if not better than anywhere across the UK".
"This life-saving service is a vital part of our NHS in Scotland, providing care day-in and day-out for children who need it, and we are determined to keep it that way," he said.
Health Secretary Nicola Sturgeon said the PICU provided a "high-quality service" and the health board was addressing the staffing issues.
She said: "The staff of the RHSC provide excellent care to the children and parents who rely on them and this report shows just how much the service is valued by those who need it.
"Our service treats around 300 children each year, working with three surgeons who will each undertake 100 operations each year.
"The fact that this unit provides a high-quality service is backed up by UK published data that show the Yorkhill results and outcomes are just as good as other centres in the UK. This is why I believe that the current provision at Yorkhill should be maintained."