Wednesday, 15 April 2020

How letting patients in intensive care lie FACE DOWN boosts their chances of surviving

Lying intensive care patients with coronavirus face down on their beds could make them more likely to survive, doctors say.
Prone positioning, in which patients who struggle to breathe are laid on their front instead of their back in a hospital bed, works by reducing pressure on the lungs.
Doctors in the UK, US, Italy and Portugal are all known to be using the technique to try and boost the survival odds of patients on life-support ventilators.
A study published in 2013 by doctors in France and Spain who were treating a different type of lung infection said patients' survival was 'significantly higher' if they were laid face down.
Medics using it in the COVID-19 outbreak now say it is 'simple' and 'saving lives' simply by virtue of reducing pressure on the lungs.
The technique is being used within the NHS and one doctor in Essex, who said it is the 'only way' to get air deep inside the lungs, explained how people with mild breathing problems can even help themselves by doing it at home. 
It works, experts say, by reducing the amount of pressure put on the lungs by the chest and opening up larger sections of the airways, lessening the damage caused by air being forced in by the ventilator and also improving oxygen uptake.
Medical workers in Santa Maria Hospital, Lisbon, are seen flippin a ventilated patient into the prone position to help with his breathing
Medical workers in Santa Maria Hospital, Lisbon, are seen flippin a ventilated patient into the prone position to help with his breathing
Images emerged of coronavirus patients lying face down in intensive care in the Cremona Hospital in northern Italy
Images emerged of coronavirus patients lying face down in intensive care in the Cremona Hospital in northern Italy
Only the most seriously ill patients are taken into intensive care and put on a ventilator, a life-support machine which forces purified air into the lungs. 
Although the machines can save a dying patient, they also cause irreparable damage to the lungs because of the way they force air into the failing airways.
The lungs' inability to expand naturally means that air pushed in by the ventilator may be contained in only a small section of the airways, leading to a ballooning effect known as 'overdistention', in which the elastic tissue stretches. 
This can cause permanent damage my making the smallest parts of the airways burst or by tearing previously healthy tissue.
If people are laid on their backs, downward pressure from the fat and muscle in the chest may reduce the already-weakened lungs' ability to expand, raising the risk of this damage and in turn making the process more deadly.
Flipping the patient over may relieve some of this pressure, doctors say.
And one NHS doctor, Dr Sarfaraz Munshi, who works at Queen's Hospital in Romford, Essex, said there is a greater surface area in the back of the lungs than at the front, meaning oxygen absorption is more efficient if air can reach those parts.
One team from France and Spain published a detailed study about the procedure in 2013 in the prestigious New England Journal of Medicine.
They wrote: 'Prone positioning, as compared with supine positioning [belly-up], markedly reduces the overinflated lung areas while promoting alveolar recruitment.
'These effects (reduction in overdistention and recruitment enhancement) may help prevent ventilator-induced lung injury by... the distribution of stress and strain within the lungs.'
The technique is now being used for COVID-19 patients, the most seriously ill of whom suffer devastating lung failure caused by severe pneumonia.
'We're saving lives with this, one hundred percent,' one regional critical care director working in New York, Dr Mangala Narasimhan, told CNN.  
'It's such a simple thing to do, and we've seen remarkable improvement. We can see it for every single patient.'
In the UK, doctors' guidance given by the Intensive Care Society and the Faculty of Intensive Care Medicine says prone positioning 'should be considered' for people who have very low levels of oxygen in the blood (hypoxaemia). 
Low blood oxygen level is one of the most noticeable effects of the coronavirus and is what leads many patients to needing intensive care in the first place. 
It is caused by lungs being so damaged by the virus and the body's own immune response that patients cannot draw enough oxygen out of the air to circulate it round the body.
The Intensive Care Society's guidance says: 'Over the last two decades randomised controlled trials have consistently demonstrated that oxygenation can be significantly improved in patients with acute respiratory distress syndrome (ARDS) when ventilated in the prone position.'
Acute respiratory distress syndrome is the medical term for when someone's lungs fail to get enough oxygen into the blood and it becomes life-threatening.
One NHS doctor said flipping a patient onto their front is, in some cases, the 'only way' to get air deep into their lungs.
Dr Sarfaraz Munshi said the practice is used on intensive care patients but can help anyone fight off infection - even if they only have mild problems and are still at home.
Dr Munshi explained in a video that his nursing colleagues rely on the technique to help patients in intensive care every day.
But patients who are self-isolating at home suffering symptoms can also benefit if their condition is only mild. Anyone who has serious trouble breathing should call NHS 111 if it is tolerable or 999 if they are struggling to breathe at all. 
Dr Munshi said to do the breathing technique twice before lying flat on the stomach and breathing deeply for ten minutes.
He said: 'The majority of your lung is on your back, not on the front. By lying on your back you're closing off more of the smaller airways and this is not good during a period of infection.
'[It can] lead to atelectasis. This can then lead to a secondary pneumonia.'
Atelectasis is a complete or partial collapse of the entire lung. It occurs when the tiny air sacs, called alveoli, become deflated or filled with fluid.
Dr Munshi went on: 'The most important thing is laying in bed for prolonged periods, on your back, is going to close off the small airways.
'[It will] increase your risk of secondary pneumonia, that can make your condition deteriorate much further - bearing in mind the patients that are deteriorating are deteriorating because of respiratory problems.'

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