It is "remarkable and inexcusable" that a design flaw which delayed the opening of the new sick kids' hospital in Edinburgh by 20 months went undetected for years, lawyers have said.

In their final submission to the Scottish Hospitals Inquiry (SHI), the legal team representing parents and families affected by problems at the Royal Hospital for Children and Young People (RHCYP) said it was "bewildering" that potentially dangerous errors in the ventilation system were only flagged in an eleventh hour inspection days before the facility was due to open in 2019.

The faults meant that critical care areas had only four air changes per hour instead of the required 10, increasing the risk of infections for highly vulnerable patients.

The hospital finally fully opened in July 2021, following £16 million of remedial works.

READ MORE: 'Human error' led to ventilation flaws which could have exposed patients to a range of infections  

The inquiry previously heard that a "human error" in a technical spreadsheet known an Environmental Matrix, dating back to 2012 and provided to project bidders by NHS Lothian, led to the incorrect air changes being applied.

However, NHS Lothian and IHSL - the private consortium awarded the contract to build the RHCYP - have blamed one another for the failure to detect and remedy the mistake.

The Herald:

However, in their submission, Thompsons Solicitors said it was "clear from the evidence" to the inquiry that NHS Lothian "failed to make the key requirements for the ventilation system clear to those who were bidding for the construction contract" which "led to confusion among all parties involved".

They state: "It is utterly astonishing that patient safety was dealt with in such a slack and haphazard fashion.

"There can be no doubt that it was for NHSL to specify, with absolute clarity and accuracy, the ventilation requirements for the patient rooms within their hospital.

"They failed to do so.

"It was also for the NHSL, and their expert advisors, to consider, assess and have regard to the readily available technical guidance for the ventilation requirements for different types of rooms within the hospital.

"If guidance specified that certain types of room should have a specific number of air changes per hour then that should have been abundantly clear to those designing and bidding to build the hospital.

"It was, or ought to have been, obvious that any failure to follow guidance could give rise to a real danger to the health and wellbeing of patients attending the hospital, principally an increased risk of infection."

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The Herald:

The submission added: "How such an obvious error was allowed to occur/missed in a high cost project involving significant public expense has not been explained by any witness, whether from NHSL or any of their advisors.

"That is both remarkable and inexcusable."

IHSL signed a deal in 2015 to design, build, finance and maintain the new children's hospital over 25 years as part of a PFI-style Non-Profit Distributing (NPD) system.

The total cost now exceeds £430m.

The consortium includes Brookfield Multiplex, the company behind the construction of the Queen Elizabeth University Hospital in Glasgow whose design, build and maintenance is also being investigated as part of the inquiry to determine whether there is any link to patient infections and deaths.

In its response to the inquiry in relation to the Edinburgh hospital project, lawyers for Multiplex said it was the firm's "understanding" that the matrix document "contained the board's desired environmental requirements".

During the preferred bidder phase, it said the matrix was "reviewed and discussed in detail with NHSL" but "at no point was IHSL or Multiplex advised that the Environmental Matrix provided by NHSL could not be relied upon or contained an 'error'".

The Herald: The Scottish Hospitals Inquiry is being chaired by Lord BrodieThe Scottish Hospitals Inquiry is being chaired by Lord Brodie (Image: PA)

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However, in its own response to the inquiry NHS Lothian insisted that its brief to tenderers "made it overwhelmingly obvious that [the company appointed] was going to be required to provide facilities that complied with all relevant guidance".

It said that the Environmental Matrix was "not a fixed client brief", adding: "Even if there was any uncertainty or ambiguity around the status of the Environmental Matrix provided to tenderers, it was incumbent on the tenderers during the dialogue phase, and IHSL during the preferred bidder stage, to flag up any issues.

"They did not do so."