The number of intensive care beds in Scotland is to increase four-fold ahead of an expected surge in critically ill coronavirus patients.

Health Secretary Jeane Freeman said work was already “well advanced” to double intensive care capacity, but that plans are now under way to create more than 700 intensive care beds.

HeraldScotland: Camley's Cartoon: Coronavirus lockdown.Camley's Cartoon: Coronavirus lockdown.

The Herald understands that clinicians in intensive care units (ICU) across Scotland were asked by the Scottish Government late last week to draw up urgent plans on how to ramp up capacity even further.

It follows alarm over the huge death tolls from Covid-19 unfolding in Spain and Italy, and reports on Friday that a London hospital’s ICU was already full.

However, one medic told The Herald that providing enough competent and experienced staff to run the hugely expanded ICU capacity “will be a major challenge”.

On Monday, Scotland’s Chief Medical Officer, Dr Catherine Calderwood, said there were 23 people in intensive care in Scotland with the virus.

This is expected to increase rapidly in April, in line with patterns seen elsewhere in Europe.

In Scotland, there are now 584 confirmed cases of the new strain of coronavirus and 16 patients who tested positive have died.

London and the south-east of England are seeing the highest concentration of cases in the UK , however, with the ExCel Centre in London now set to be transformed into a temporary hospital to accommodate 4,000 patients.

Addressing the Scottish Parliament, Ms Freeman said she had now received mobilisation plans from all of Scotland’s health boards detailing how they will “maximise intensive care capacity whilst seeking to maintain essential services such as emergency cancer and maternity care”.

Under normal conditions, around 60-70 per cent of Scotland’s ICU beds are occupied at any one time.

NHS Scotland has already suspended all planned operations such as hip and knee replacements, but freeing up extra space to be converted into intensive care means any surgery which can be delayed – such as non-urgent cancer or some complex operations with longer recovery times – are likely to be shelved.

There are also hopes that social distancing will contribute to a fall in trauma, such as road crash casualties, with fewer people leaving home.

Ms Freeman said: “We are well advanced in our work to double ICU capacity to 360 beds. “Facilities have been repurposed, staff are being trained, and beds are being freed up. Our response to double ICU capacity is the international standard in response to a pandemic.

“But given the scale of the challenge, we’re now planning to quadruple our ICU capacity to over 700 as quickly as we possibly can.

“A pipeline of ventilators is slated to come to Scotland in the coming weeks to enable this increase, and we are working with suppliers to do all that we can so that they can be brought here as quickly as is humanly possible.”

Ms Freeman had previously talked of doubling intensive care capacity “from 190 to 380 beds” – not 360 – which would mean creating 760 ICU beds.

The Scottish Government on Tuesday night declined to say exactly how many beds it was aiming for through a quadrupling of capacity.

Ms Freeman also confirmed that parking charges would be scrapped from Monday at Scotland’s three privately owned car parks at Glasgow Royal Infirmary, and Edinburgh Royal Infirmary, bringing them into line with NHS sites.

Ms Freeman added that some 3,300 retired NHS staff had also responded to an appeal to return temporarily as part of efforts to beef up the workforce as coronavirus cases peak.

Meanwhile, the UK Health Secretary Matt Hancock announced the ExCel exhibition and conference centre in London is to be converted into a temporary hospital, the NHS Nightingale hospital, to take an overspill of patients as hospital wards fill up.

It will ultimately comprise two wards, each of 2,000 people, and has been set up with the help of the military.

However, initially it will provide about 500 beds equipped with ventilators and oxygen.

Similar ad hoc facilties have been created in Madrid and New York using convention centres, and in France one hospital has turned its car park into a field hospital.

It came as it was revealed that the number coronavirus deaths in the UK had reached 422, a jump of 87 in a single day – the largest increase since the outbreak began.

Mr Hancock issued an appeal for NHS “volunteer responders” to assist with the national effort to tackle coronavirus by shopping, delivering medicines and supporting people with high-risk conditions who have been told to shield themselves from the virus at home for 12 weeks, without going out.

Mr Hancock’s announcement comes after the Government faced criticism over its policy on workers, with pictures of packed London Tube trains appearing for a second day in a row on social media.

In measures announced on Monday, Prime Minister Boris Johnson told people to only go to work if “absolutely necessary”.

But on Tuesday, Mr Hancock said those who cannot work from home, including key workers in the NHS and social care, should go to work “to keep the country running”.

Mr Hancock said construction workers were among those who could continue to work as long as they could remain two metres apart at all times.

In Scotland, First Minister Nicola Sturgeon said construction sites should down tools immediately unless what they were building was “essential”, such as a hospital. She added that staying at home is “the only way of saving lives” as the number of people infected with Covid19 continues to grow.

Under the UK-wide lockdown, people should only leave their house to exercise once a day, to go to work if they