£200,000 appeal: Grounded planes could be trialled as oxygen chambers for Covid-19 patients, says Lungfish Dive Systems
Could grounded aeroplanes be used as makeshift oxygen chambers to help Covid-19 patients?
The idea is being explored by South Cambridgeshire business Lungfish Dive Systems, which specialises in breathing systems for scuba divers.
A clinical trial using hyperbaric oxygen therapy (HBOT) in a chamber is planned in Canada - and if it proves successful, Lungfish wants to help make the approach widely available. It is helping to raise £200,000 towards the trial of the approach.
“The disease interferes with people’s ability to get enough oxygen into their body,” Lungfish founder Dr Daniel Reynolds tells the Cambridge Independent.
“Even ventilation is not sufficient. In theory, by breathing oxygen under pressure, that will squeeze more in to get through the difficulty in the lungs.
“But you cannot just pressurise the lungs. You have to pressurise the whole patient because you can’t breathe compressed air.
“We believe this has not been explored much because there are inadequate numbers of pressure chambers available for such a treatment.”
With so many planes on the ground, Dr Reynolds believes the idea of converting them for medical use is feasible.
“At the altitude at which aircraft fly, there’s not enough oxygen to breathe. So the pressure inside the plane must be maintained at near ground level pressure.
“As a result, any commercial aircraft can operate with an overpressure inside it,” he explains.
The company, based in Litlington, has held discussions with aerospace companies about the conversion required to enable planes to operate with a pressurised cabin at ground level, and for seats to be removed as required to create the necessary space.
“We’ve established that it could be done. What we need to establish is whether it should be done, and how,” he says.
“We’ve consulted with Robert Marshall of Marshall Aerospace in Cambridge, and planes are available and could be adapted. For instance it would take about a day and a night to remove every single seat from a typical airliner. But far less would be needed. Initially, you would probably use business class because the seats recline.
“Experts are now devising the procedures for it, and our hope is that this work will be done simultaneously with the clinical trials.”The Canadian trial, planned at a hospital-based hyperbaric chamber, still requires some funding and volunteers must be recruited once the concept has passed through an ethics committee. But the aim is to explore conditions that could be replicated in an aircraft.
“After the first 20 people have been through, they will have an idea if it’s doing any good. The trial will go to larger numbers if the protocol needs to be optimised,” says Dr Reynolds.
“The reason why we would stick our necks out is there is an enormous casualty rate. I’d rather we look silly if it doesn’t work, than allow people to die because we were too cautious.”
Two-thirds of Covid-19 patients in the UK who are placed on ventilators die. In China and New York, mortality rates for those on ventilation have been as high as 80 per cent.
The numbers have prompted some debate in the medical profession on whether the approach of using mechanical ventilation is even the right one.
Only used for the sickest of Covid-19 patients, it is an invasive procedure that requires a tube to be inserted into the airway, with medication administered to relax the respiratory muscles.
Non-invasive ventilation using facemasks, nasal masks or mouthpieces is used for those with milder symptoms, while CPAP (continuous positive airway pressure) devices that deliver oxygen into the lungs without the need for an invasive ventilator are now being trialled in the UK, after being made by Mercedes F1 and University College London.
Hyperbaric chambers could provide another option for clinicians for those whose oxygen levels are starting to fall.
Typically used to treat those with diving-related illness, and used in some countries for other medical purposes, these chambers supply almost pure oxygen under pressure. While the UK has scores of them, they are small and not always located near hospitals.
“All of the UK ones are currently closed because in the absence of a clinical trial, their experts and equipment have been moved,” says Dr Reynolds.
Lungfish hopes to secure further clinical trials in the UK to help determine efficacy and dosage, explore which patients might benefit most and learn about any complications.
He believes that to benefit, patients would need to be inside such a chamber for several 90-minute cycles a day, over several days.
“It’s a race against time to secure partners for further clinical trials,” says Dr Reynolds.
“At the current casualty rates, if the treatment proves effective, one day’s difference in response speed could mean a difference of thousands of lives saved.”
It may sound something of a departure for Lungfish, but its day-to-day work is also geared towards life support.
Its advanced closed-circuit rebreather systems enable divers safely to spend longer in the water.
“When you are scuba diving you normally have a giant cylinder which weighs a lot, produces a lot of noise and bubbles and doesn’t last all that long,” says Dr Reynolds.
“With our device, because it recirculates, no oxygen is wasted. It scrubs out the carbon dioxide, measures the oxygen level and tops it up to the desired level.
“You have a little two-litre oxygen cylinder, which will last you about four hours regardless of depth.
“It makes no noise and you can do more or less what you like, because as it’s controlling the gas mixture, the decompression can be optimised as well. We supply these for things like natural history filmmaking because they can take your time and wait for whatever it is to happen.”
The company has also worked on hyperbaric physiology, helping researchers study the effect of diving on the body.
“My perspective is from the physiology side, although I do much of the design work too,” explains Dr Reynolds, who founded the company in 2008. “We have others from avionics fields, which is the aerospace tie-in, which is why we’re in the position to do this now.”
And if Litlington sounds an unlikely location for a dive company, Dr Reynolds points out that Cambridge’s talent pool is critical for the work.
That talent could now be brought to bear on the Covid-19 crisis.
Support the £200,000 fundraising appeal at https://www.justgiving.com/crowdfunding/covid19hbot.