Saturday, January 16, 2021

Zoom Meeting on the Melbourne Isolation Hood to stop spread of Covid in Hospital


You are invited to a  Zoom meeting on the Melbourne Isolation Hood
Time: Jan 28, 2021 09:00 London time

The Isolation Hood is designed to cut the risk that Covid-19 patients in hospital spreading the infection to fellow patients or to Nurses, Doctors and other front-line health care workers.
It does this by capturing all droplets and aerosols breathed out by the patient and drawing them through a High Efficiency Particulate Air (HEPA), where the virus is trapped and inactivated.

The Isolation Hood (also known as the McMonty Medihood) is in production in Melbourne, Australia, and 80 units are in use in six Australian cities, all within ICUs and wards.

It has been welcomed by front line health care workers, who feel more secure when the Hood is in use.

One unit has been kindly donated free of charge to the NHS by the manufacturers, Evan Evans of Melbourne, and is being installed in the renal unit of a hospital in the South West, since if patients on renal dialysis contract Covid-19 they are at risk, on account of being on immune suppressant medication.

The speaker at the Zoom meeting will be Dr Forbes McGain, a consultant anaesthetist, who developed the Medihood in collaboration with Prof Jason Monty, Professor of Engineering at the University of Melbourne. He will speak for 30 minutes, leaving plenty of time for questions.


Medihood website

Aerosol generation relative to respiratory interventions and the effectiveness of a personal ventilation hood McGain F et al, Critical Care and Resuscitation

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Friday, January 01, 2021

We Can Cut the Number of Hospital Acquired Covid Infections

The virus that causes Covid-19 is spread mainly by inhaling droplets from infected people who are within two metres or less, and by aerosols of virus particles, which may persist in air for 30 minutes or more.

10-20% of hospitalised  Covid-19 cases caught the virus in hospital.

This situation can be improved with some pretty basic technology.  

The transmission risk from Covid-19 cases

People in hospitals who are known to be infected with Covid-19 are putting out droplets containing the Sars-CoV-2 in large amounts when they cough, speak and breathe , especially in the first week since symptoms began.

People with Covid who are receiving oxygen delivered via mask or cannula will be continually exhaling droplets into the hospital environment. The air in their vicinity and in their room will contain a considerable quantity of virus, both as droplets and as aerosols.

Bed coverings and the floor within a couple of metres will be hosting significant amounts of virus. This virus will feed back onto the patient, continually re-infecting them every time they breathe in, or when they touch their face after letting their hands rest on their sheets. The floors can be cleansed at frequent intervals, but the bed linen presents an infection risk to anyone who handles it.

The health and safety of health care workers needs to be protected

The air in the vicinity of the patient poses a health and safety risk to anyone who enters the room or indeed breathes air in the vicinity of the room. PPE is used to reduce this risk, but PPE does not present an impenetrable shield, and 649 healthcare workers (including 36 doctors) have died from Covid-19 contracted while giving care.

The simplest way to capture expired air is by means of a hood positioned over the head. Air will be withdrawn from the hood through a tube positioned above the head at a rate greater than 6 litres/minute, which is the volume of air that is exhaled by a human at rest. The material of the hood will be of transparent plastic that can be sterilised. This hood will produce an upward flow of air across the face, and all expired air will be safely collected.

I produced Figure 1 below with the help of a professional artist friend, (thanks Stephan Marjoram). It shows one configuration of an air management hood. In this embodiment, the hood is open, and the body of exhaled breath is managed by the flow of air. This was my concept, and is very similar to the NIOSH hood (below) but I have abandoned development in favour of the market-ready Medihood.

Figure 1

Friday, December 04, 2020

JCVI has not thought through their vaccine prioritisation

My letter to the Guardian today

"NHS staff no longer top priority to receive coronavirus vaccine" (p1, 4th December). This is because the Joint Committee on Vaccination and Immunisations (JCVI)  advises that the first priority should be prevention of mortality, and to do this they have opted for immediate protection of very vulnerable elderly people in care homes, rather than general prevention of mortality by using the vaccine to reduce the reproduction rate (R-number)  of the virus.

JCVI did model the use the vaccine to interrupt transmission of the virus in society, but decided that this would only take place when a majority of the general population had been vaccinated, which would take many months to come about. It appears that they did not model giving the vaccine to potential super-spreaders, to people who encounter scores or even hundreds of other people during the course of their working day. People like doctors, nurses and other front-line health care workers, teachers,  police officers, postal workers, shop workers, delivery drivers and many other groups who keep the real economy actually turning over. The key point is that these workers are at increased risk both of contracting the disease and also of transmitting the disease.

If Government chose to vaccinate these public-facing workers, they would not only be reducing the R-number and therefore lifting the curse that the nation is under, but they would also be assuaging the concerns of those on the political right of their party and further afield who argue that the "cure is worse than the disease". This lobby has a real influence on people's behaviour in terms of non-compliance with the rules and guidelines.

It is not too late even now for the Government to allow NHS staff and other front-line workers to be vaccinated against the disease that poses such a threat to their work, their lives and the national economy.

Dr Richard Lawson


Thursday, December 03, 2020

The Changing of the Shared Narrative

 In his excellent book, Sapiens, a Brief History of Humankind , Yuvak Noah Harari shows how humans cooperated on the basis of shared myths. These stories enabled increasingly large empires to evolve from modest towns such as Jericho about 8500 BC to the Qin dysnasty in China 225BC that organised some 40 million subjects. 

These myths were sufficiently powerful to motivate people to accept order and discipline prescribed by the elite. The myths to a greater or lesser extent explained how the world came into being, why things happened in history, why things are the way that they are, and where things were ultimately heading for. 

Early myths were primarily theological. They began with strictly limited gods who were primarily there to protect a town or kingdom provided the right rituals were observed. Later, the gods became interested in protecting whole cultures of their devotees, be they Christian, Muslim or Jewish.

Although these myths persist into modern life, the operative myth of our times since the mid 18th century is, of course, Money. "It's the economy, stupid" in the oft-quoted phrase of Bill Clinton's campaign manager. Money makes the world go round. 

Money, in the modern myth, is not just a means of exchange and a store of wealth, it is a commodity that can be created out of nothing, on a promise of future returns. Money is created in the act of making an interest-bearing loan, and need to repay interest is the key driver of Economic Growth, which is the patently absurd belief that it is possible for material human constructs to grow indefinitely in a finite planet.

The creed of Money can be summarised as "Fallible men, competing against each other for the sake of material greed, in the absence of any restraint or regulation, will produce the best of all possible worlds".

This belief is quite obviously false. The devotees of free market fundamentalism  trumpet their success in creating enormous wealth, but their success is at the expense of global heating, mass extinctions, and growing armies of impoverished people.

The myth of the free market has run its course. It is finished, dead. 

What then will take its place?

We need not an imagined myth, but an accurate narrative of how we got here, why things are the way thing are, and where we are going. Not a made up myth, but a true and scientific account of the situation.

The narrative exists already. It is the ecological account of reality. It is the realisation that we humans are a social mammalian species who have evolved on this planet in an amazingly successful way using technology that has released stored solar energy. Unfortunately the process has had a severe and unacceptable side effect of altering the energy balance of the planet, so that the continuation of our human civilisation depends on making a very rapid transition away from using up the energy capital represented by fossil carbon, towards using the energy income offered by the Sun. At the same time we need to change our attitude to other species, from seeing them as resources to be exploited to seeing them as a network of life to be respected and protected.

This change of world view, and the technical changes associated with it, is a huge challenge, but it is possible for us to succeed in it. We have changed world views before and we can do it again.