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Comment by simonh | Hacker News Reader

These are only used by doctors and nurses when treating patients with open airways at very close range to protect from direct splatters with body fluids. Eg when intubating a patient that’s having explosive coughing fits. They are also part of a complete protective system including a mask, elasticated hair cover, full body wrap aprons and long arm gloves. There is no point using a shield without the rest if the gear because if you are in a situation where you need the shield, you also need the rest as well.

Most medical professionals don’t even wear this full kit routinely in hospitals, let alone when they are out in public, so there’s no need for the public to use them in general working conditions.

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> There is no point using a shield without the rest if the gear because if you are in a situation where you need the shield, you also need the rest as well.

This is the same class of bullshit the WHO, CDC and FDA were pushing about face masks less than a week ago. There is no way this is worse than nothing. If a face shield used with no other PPE reduces the viral load the average healthcare worker is exposed to by 1% fewer people will be infected and those who do will be more likely to recover as their immune system has more time to ramp up defenses.

This will reduce R0. There is no plausible mechanism of action for a face shield to work as PPE together with a respirator, or as part of a full suit of PPE, under which it provides no protection when used alone.

> There is no way this is worse than nothing.

correct. it's not worse than nothing. it's literally not possible to be "worse than nothing".

However to your point it only protects against spray. So, yes, it's better than nothing if you're in front of someone coughing / vomiting directly on you.

BUT it doesn't do much of anything for the aerosolized particles. Better masks has coverings above the top to prevent those from coming in from above, but in this case apple appears to be going for quantity and speed over quality.

> if a face shield used with no other PPE reduces the viral load the average healthcare worker is exposed to by 1%

If you are practicing social distancing then a face shield really provides essentially zero protection. I have seen no evidence or even suggestion by a medical professional that wearing these while keeping a distance from infected individuals would provide ANY protection.

The main problem is aerosolized material (also direct contact but gloves and not touching your face address that). These don't help with aerosolized material. It just floats around them and gets inhaled anyway.

You want these if you are up close to someone who is infected or potentially infected because mouths spew forth bad things: vomit, coughing, etc. and you frequently don't have time to jump out of the way.

> it's literally not possible to be "worse than nothing"

(I upvoted you. I don't think you deserve downvotes).

It is worse to be better than nothing if it increases risk, and if people don't know how to take it off.

If it's only for that narrow use case then a million per week seems excessive and unnecessary.

There are about a million infected individuals right now, and climbing, and each hospitalised patient in ITU may need these procedures several times a day. An ITU team performing the procedure might consist of 2 to 4 people and the shields should be discarded every time. The number of patients is also rising rapidly, so demand is very high.

When you see doctors and nurses in full scrubs with face shields doing their shopping, then you know you need this equipment. However if you're really concerned there are other options[0].

[0]https://www.amazon.com/Sinoocean-Astronaut-Spaceman-Costume-...

> and the shields should be discarded every time

Maybe I'm missing something, but the page literally has a section titled "Clean and reuse your face shield" and lists the chemicals that should be used to clean it.

Thats because demand is so high and supply so short that they are being re-used.

The doctor or nurse probably won't be able to do that process everytime they use the mask. Like other reusable hospital supplies it will be collected somewhere to be cleaned in bulk. The point above is that so many will be used in a short span of time that even a 24 or 12 hour cleaning rotation will not keep up without large numbers being available.

Mask => Shield

(Like many, I think I've got "masks" on the brain...)

this should only be done when you're so screwed that you don't have clean ones available. This is literally war-time thinking. It's also completely impractical to do at hospital scale, but if it's your only option...

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