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Coronavirus: What are ventilators and why are they important? Coronavirus: What are ventilators and why are they important?
(2 days later)
The government has ordered thousands of ventilators to help ease the pressure on hospitals caused by the coronavirus crisis. The government has said it will buy thousands of ventilators to help ease the pressure on hospitals caused by the coronavirus crisis.
For patients with the worst effects of the infection, a ventilator offers the best chance of survival. For patients with the worst effects of the infection, a ventilator can offer the best chance of survival.
What is a ventilator and what does it do?What is a ventilator and what does it do?
Simply put, a ventilator takes over the body's breathing process when disease has caused the lungs to fail.Simply put, a ventilator takes over the body's breathing process when disease has caused the lungs to fail.
This gives the patient time to fight off the infection and recover.This gives the patient time to fight off the infection and recover.
Various types of medical ventilation can be used.Various types of medical ventilation can be used.
According to the World Health Organization (WHO), some 80% of people with Covid-19 - the disease caused by coronavirus - recover without needing hospital treatment.According to the World Health Organization (WHO), some 80% of people with Covid-19 - the disease caused by coronavirus - recover without needing hospital treatment.
But one person in six becomes seriously ill and can develop breathing difficulties. But one person in six becomes seriously ill.
In these severe cases, the virus causes damage to the lungs. The body's immune system detects this and expands blood vessels so more immune cells enter. In these severe cases, the virus causes damage to the lungs, causing the body's oxygen levels to drop and making it harder to breathe.
But this can cause fluid to enter the lungs, making it harder to breathe, and causing the body's oxygen levels to drop. To alleviate this, a ventilator is used to push air, with increased levels of oxygen, into the lungs.
To alleviate this, a machine ventilator is used to push air, with increased levels of oxygen, into the lungs. The ventilator also has a humidifier, which adds heat and moisture to the air supply so it matches the patient's body temperature.
The ventilator also has a humidifier, which adds heat and moisture to the medical air so it matches the patient's body temperature.
Patients are given medication to relax the respiratory muscles so their breathing can be fully regulated by the machine.Patients are given medication to relax the respiratory muscles so their breathing can be fully regulated by the machine.
People with milder symptoms may be given ventilation using facemasks, nasal masks or mouthpieces which allow pressurised air or mixtures of gases to be pushed into the lungs. People with milder symptoms may be given ventilation using facemasks, nasal masks or mouthpieces which allow air or an oxygen mixture to be pushed into the lungs.
University College London engineers have worked with clinicians at UCLH and Mercedes Formula One to build what is known as the Continuous Positive Airway Pressure (CPAP) device. This is known as "non-invasive" ventilation, as no internal tubes are required.
Following trials at several London hospitals, the Mercedes-AMG-HPP group produced nearly 600 of them on Monday 6 April, and hopes to increase that to 1,000 a day. Another form of ventilation - continuous positive airway pressure or CPAP - keeps a patient's airways continuously open,
Early reports from Lombardy in northern Italy suggest about 50% of patients given CPAP have avoided the need for invasive mechanical ventilation. Early reports from Lombardy in northern Italy suggest about 50% of patients given CPAP have avoided the need for full mechanical ventilation.
However, the use of CPAP machines in patients with contagious respiratory infections has raised some concern, as any small leaks around the mask could spray droplets on medical staff. A type of CPAP ventilation using a hood, where pressurised oxygen is pumped in via a valve, reduces the risk of airborne transmission of the virus.
Hoods, where pressurised oxygen is pumped in via a valve, are also being commonly used to treat Covid-19 patients, partly because they reduce the risk of airborne transmission of the virus from droplets in the breath. Intensive Care Units (ICUs) would generally put patients suffering acute respiratory distress on mechanical ventilation quickly, to ensure oxygen levels in the body stay normal.
These are known as "non-invasive" ventilation, as no internal tubes are required. However Dr Shondipon Laha, from the Intensive Care Society, told the BBC that unless they become seriously ill, most patients with Covid-19 would not need a mechanical ventilator and could be treated at home or with supplementary oxygen.
However, Intensive Care Units (ICUs) would generally put patients suffering acute respiratory distress on mechanical ventilation quickly, to ensure oxygen levels in the body stay normal. Although there were risks when using ventilators, such as not knowing who would suffer long-term effects, he said, sometimes a ventilator was "the only way of getting oxygen into the patient".
Dr Shondipon Laha, from the Intensive Care Society, told the BBC most patients with Covid-19 would not need a mechanical ventilator and could be treated at home or with supplementary oxygen. Another issue, Dr Laha explained, was having enough trained staff to operate the ventilators correctly.
But although there were risks when using ventilators, such as not knowing who would suffer long-term effects, he said, sometimes a ventilator was "the only way of getting oxygen into the patient".
Another issue, Dr Laha explained, was having enough of the right staff in place to manage all the ventilators expected to be needed.
"A ventilator is a complex beast - it can cause a patient trauma if not set up properly," he said. "The technical aspects are challenging. People have knowledge on varying types of ventilator in other specialities, but may need support in using them in intensive care if they're unfamiliar with this."
How many ventilators does the UK have - and how many might we need?How many ventilators does the UK have - and how many might we need?
Health Secretary Matt Hancock told the BBC's Andrew Marr Show on 5 April: "At the moment we have between nine and ten thousand ventilators within the NHS right now and we have the 2,000 spare that are critical care beds with ventilator capacity ready, should people need to come into them." The UK is understood to currently have about 10,000 ventilators having added to the previous stock of just over 8,000 by increasing production and sourcing other machines from overseas.
Mr Hancock said there should be another 1,500 of them by 12 April, which would take the total to between 12,500 and 13,500. A number of ventilators have also been acquired from private hospitals.
The government has reduced its target from 30,000 ventilators to 18,000 "over the coming weeks". Health Secretary Matt Hancock has said the country needs 18,000 machines for when the virus peaks, down from an original estimate of 30,000.
An order has also been placed by the government for 10,000 newly-designed machines from technology firm Dyson. Mr Hancock told the BBC's Andrew Marr programme on 5 April that projected demand had come down because social distancing measures were working.
Company insiders have told the BBC Dyson has a working prototype, designed and built from scratch, which has been tested on humans and is "ready to go". The exact type of extra ventilators needed, and who makes them, is still being finalised.
A further order of 5,000 machines could come from Luton-based Smiths group, possibly its portable ParaPac model. The delay is linked to a changing understanding of how to treat patients requiring ventilation, according to the Financial Times.
Another British company, Gtech, has designed a prototype which can run entirely off the hospital oxygen supply without the need of a power source. A consortium of UK manufacturers is leading efforts to produce a version of a machine built by Oxfordshire company Penlon. On 16 April, it was announced that the Penlon Prima ESO2 devices had been approved and that hundreds are expected to be built for hospitals over the next week. By the start of May, it is hoped that 1,500 a week will be made.
A number of other companies - including a consortium of Airbus, Meggit and GKN - are also lining up to supply further ventilators based on existing designs. As part of that same initiative, the first ventilators - portable ParaPac devices from Luton-based firm Smiths - have been delivered to wards over the last few days.
Meanwhile, a team of scientists and engineers from Oxford University and King's College London has unveiled its own low-cost design, which it says could be quickly put into production. The consortium includes Airbus, Rolls Royce and a number of Formula One racing teams.
And researchers at the University of East Anglia are looking at using 3D printing to quickly produce ventilator parts, as well as masks and other essential equipment. A separate machine being designed and built from scratch by Dyson is also being considered by the government.
Production of other types of non-invasive ventilator is also being scaled up, with a government order of some 10,000 Ventura CPAP devices designed by University College London Engineers with industry partners Mercedes-AMG-HPP.