Manufacturers work on blueprint to create 30,000 NHS ventilators

The government has asked manufacturers including Airbus, Rolls-Royce, Nissan and JCB to help produce up to 30,000 ventilators in as little as two weeks, amid concern that the 8,175 the NHS has available will not be enough to treat a surge in Covid-19 patients.

As manufacturers race to heed that call, in an effort some have likened to British industry’s effort to help produce Spitfires during the second world war, every effort is being made to support them, both by government and the broader business community.

Quick guide

What to do if you have coronavirus symptoms in the UK

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Symptoms are defined by the NHS as either:

• a high temperature – you feel hot to touch on your chest or back
• a new continuous cough – this means you’ve started coughing repeatedly

NHS advice is that anyone with symptoms should stay at home for at least 7 days.

If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home.

After 14 days, anyone you live with who does not have symptoms can return to their normal routine. But, if anyone in your home gets symptoms, they should stay at home for 7 days from the day their symptoms start. Even if it means they’re at home for longer than 14 days.

If you live with someone who is 70 or over, has a long-term condition, is pregnant or has a weakened immune system, try to find somewhere else for them to stay for 14 days.

If you have to stay at home together, try to keep away from each other as much as possible.

After 7 days, if you no longer have a high temperature you can return to your normal routine.

If you still have a high temperature, stay at home until your temperature returns to normal.

If you still have a cough after 7 days, but your temperature is normal, you do not need to continue staying at home. A cough can last for several weeks after the infection has gone.

Staying at home means you should:

• not go to work, school or public areas
• not use public transport or taxis
• not have visitors, such as friends and family, in your home
• not go out to buy food or collect medicine – order them by phone or online, or ask someone else to drop them off at your home

You can use your garden, if you have one. You can also leave the house to exercise – but stay at least 2 metres away from other people.

If you have symptoms of coronavirus, use the NHS 111 coronavirus service to find out what to do.

Source: NHS England on 23 March 2020

HSBC said on Monday it would help companies working on the project by offering fast-track loan applications, cheaper interest rates and extended repayment terms to support the unprecedented demand on UK hospitals.

This will help firms concentrate on the tricky part: satisfying the strict criteria for suitable ventilators, laid down by the Department of Health and Social Care.

The DHSC’s specifications for a “minimally acceptable” rapidly manufactured ventilator systems (RMVS) are:

• Ventilators must be reliable and able to keep working 100% of the time for at least 14 days.

• They should also be small and light enough to fix to a hospital bed, but robust enough to survive falling from bed to floor without affecting their ability to operate.

• The machines must be able to provide both mandatory ventilation – breathing on behalf of the patient – as well as a pressure support mode that assists those who can breathe independently to some extent. The machine should be able to sense when a patient stops breathing and switch from the assisted breathing mode to a mandatory setting.

• The machines will obviously have to be able to connect to hospital gas supplies and will also need at least 20 minutes of backup battery in case of mains power failure. The batteries should be swappable in case of a longer outage, or a patient transfer that could last two hours.

• This could be tricky. Buried at the end of the government’s specification document is a warning that requiring backup batteries will mean that 30,000 large batteries need to be sourced quickly. The government admits it will “need the advice of an electronic engineer with military/resource-limited experience before specifying anything here. It needs to be got right first time.”

• All of the ventilator’s parts need to be detachable so they can be disinfected manually.

• They must also be fitted with an alarm that alerts medical staff in case of a fault or some other interruption or inadequacy of oxygen supply.

• Doctors must be able to monitor the ventilator’s performance, for instance the oxygen percentage it is providing, via clear displays.

• Operating the machine must be intuitive, requiring no more than 30 minutes of training for a medical professional who already has some ventilator experience. Some of the instructions should also be included on the external labelling.

• Specifications include the ability to support a range of 10 to 30 breaths per minute, rising in increments of two, with the settings adjustable by medical professionals. They should also be able to change the ratio between the length of time for breaths in and breaths out.

• The document includes a minimum for the amount of oxygen the ventilator should be able to pump into a patient’s lungs. Tidal volume, the amount of air someone inhales during a normal breath, is typically about six or seven ml per kilogram of body weight, or around 500ml for someone weighing 80kg. The minimum requirement for a RMVS is a single setting of 450. Ideally it could move on a spectrum between 250 and 800 in increments of 50, or be set to a ml per kg setting.

• The average proportion of oxygen in the air is 21%. The ventilator should offer 50% and 100% at the very least and ideally 30% to 100% rising in increments of 10 percentage points.

• The Medicines and Healthcare Products Regulatory Agency (MHRA) is the UK body that approves medical equipment for use. It will have to give the green light to any ventilators used in the Covid-19 response. Manufacturers must show their supply chain is contained within the UK, to ensure no disruption in the event that cross-border freight movements are interrupted. The supply chain must also be transparent so that the MHRA can ensure suitability of parts.

• Ventilators must meet certain existing standards for MHRA approval, however the DHSC said it was considering whether these can be “relaxed” given the urgency of the situation.