CORONA Improvised vents - question for healthcare providers/Lawyers/politicians/backwood engineers

[Old Gray Mare]

Dad was a pneumatic control specialist. At one time I was a lifeguard trained to administer oxygen in cases of a near drowning incident. So that's my background. Yes, basically ignorant.

Question: How come vents are not being improvised for the emergency? I'm not and never will be an expert that's why I'm asking. It's known at what PSI(pounds per square inch) pressure that it's needed to stay below or at not to blow someone's lungs out. As far as I know the valves/gauges are available at some plumbing supply stores. Tubing I would suspect could be gotten at a plumbing supply or auto supply shop. Dad used bottled oxygen for welding. It's not as clean as what is used for healthcare but can't it be filtered prior to delivering it to the patient? I wouldn't be surprised if many on this board have most of these supplies out in the barn or workshop.

This is an emergency not business as usual. If a vent is needed for a patient to live and it's sure death without one with a higher probability of death on a cobbled together vent than a approved for medical use vent, but still a higher chance of life than no vent at all? I'd want the cobbled together vent rather than sure death.

I know a healthcare provider would still have to monitor the patient and check oxygen levels, pressure and delivery etc.

Thoughts?

 

[moldy]

There have been suggestions about using one vent for multiple patients. The problem with that is that they must have the same settings (tidal volume, pressures, breaths per minute, amount of o2, etc). Also, if one patient can't keep up, or starts struggling, the extra pressure or volume goes to the other patient on the circuit.

I imagine there are those out there who could troubleshoot it or cobble together a vent out of the pieces you mentioned. The problem comes with administration and risk management who would shoot this down, even if it means deaths; because the 'off label' option would be more of a liability, if families sued.

 

[Creedmoor]

See AvE’s latest on YouBoob.

 

[Old Gray Mare]

The problem comes with administration and risk management who would shoot this down, even if it means deaths; because the 'off label' option would be more of a liability, if families sued.

It always comes back to the $%^& lawyers, even during a pandemic with fatalities that some project will be high.

 

[Old Gray Mare]

See AvE’s latest on YouBoob.

Very interesting. I wish Dad was still with us.

 

[Dozdoats]

I've been wondering about CPAP/BIPAP machines … from the standpoint of something being better than nothing, especially for home use.
==========

A pilot study of improvised CPAP (iCPAP) via face mask for the treatment of adult respiratory distress in low-resource settings - International Journal of Emergency Medicine

Background Continuous positive airway pressure (CPAP) is a mode of non-invasive ventilation used to treat a variety of respiratory conditions in the emergency department and intensive care unit. In low-resource settings where ventilators are not available, the ability to improvise a CPAP system...

intjem.biomedcentral.com

• Published: 05 March 2019

A pilot study of improvised CPAP (iCPAP) via face mask for the treatment of adult respiratory distress in low-resource settings

• Brendan H. Milliner,
• Suzanne Bentley &
• James DuCanto

International Journal of Emergency Medicine
/snip

 

[Old Gray Mare]

I've heard there are manual vents that can be purchased but they are only for temporary use as after about twenty minutes of squeezing the bag the operator would be exhausted or so I've been told. Not an expert. Not a licenced healthcare provider.

 

[moldy]

The problem with biPap is that it allows the dispersal of aerosols in a major way. In normal times, we would try to keep a patient on biPap instead of intubating them and putting on a vent. Due to coronavirus, we are skipping biPap and going straight to intubation.

 

[Dennis Olson]

And what about using CPAP machines?

Oops! I see that’s already been discussed. My bad.

 

[night driver]

Having bagged people for limited periods of time, I'd rather not have to bag someone for more than several minutes. Damn soon after 5-10 minutes your hands and arms fall off (ok, not really) but you lose feeling in the hands and arms...

The issue with "Admin and Lawyers" is that EVERYTHING you are using in a Hospital Setting has been type and function aproved by long term testing and such. Without that testing and certification, you don't have anything to hang your hat on if the person dies even POTENTIALLY due to the function of the machine.
Would i cobble together one?? Not really.


Now, because I'm a fossil, I remember having in my hands what we then called "manual Resuscitation Masks) where we wrere able to deliver breaths by hand triggered mask.
Laerdal used to make them but they have evaporated due to the propensity to blow out lungs because there was no limit on delivered tidal volume or pressure.

 

[night driver]

OGM, you are talking about a BVM, Bag Valve Mask.

CPAP won't help because it is Continuous Positive Air Pressure. Not gonna help when you need to deliver breath pressure and VOLUME, and allow exhalation, and do it in a timed manner. Plus CPAP won't deliver the needed pressure to inflate lungs PARTICULARLY where there is not a lot of lung compliance with ventilation.

 

[LoupGarou]

I'm playing with the idea of a modified CPAP that basically has it's impeller RPMs at about 70% of max, and on the output port, two valves letting air escape to the outside (one is servo controlled, one is a maximum pressure limiter valve) that are inline and then off to the mask, where there is a restriction exhaust port (say 3/4 inch in from the CPAP, but only 1/2 inch exhaust port) with pressure limited exhaust valve. The inline max pressure valve is just the safety valve that limits maximum fill pressure to something tolerable. The exhaust valve on the mask is what keeps the air flowing through and out the mask no matter if the patient is filling their lungs during a forced inhale (servo is letting less air from the CPAP escape before the mask), or during an exhale (servo opens up it's valve and allows the lungs to depressurize). Run the exhaust port out with a second flexible hose to a HEPA filter so that no viri were dispersed into the air.

Add in a few pressure sensors, a temperature sensor and link to the Pulse Ox sensor on their finger and the system could run on anything from an Arduino, to a full Raspberry Pi and even send alerts and stats back to a monitoring system. The Arduino could control everything from the main impeller speed, to the pressure and volume regulation as well as breath rate and CFM easily.

Loup

 

[Old Gray Mare]

OGM, you are talking about a BVM, Bag Valve Mask.

CPAP won't help because it is Continuous Positive Air Pressure. Not gonna help when you need to deliver breath pressure and VOLUME, and allow exhalation, and do it in a timed manner. Plus CPAP won't deliver the needed pressure to inflate lungs PARTICULARLY where there is not a lot of lung compliance with ventilation.

So hypothetically it would require some sort of regulator/governor providing for an intermittent delivery? Hypothetically speaking....

 

[hunybee]

i know someone with a family member that received a letter telling them they had to relinquish their cpap machine to be used as a ventilator for coronavirus patients.

yes, it works, but what about the person they are taking the cpap machine from? they need it as well.

 

[ComCamGuy]

If it’s improvised time, then the flow restricted oxygen powered ventilator device (FROPVD) mentioned earlier (push the button and inflate or explode the lungs) can be somewhat improvised with scuba gear. It has a push to inflate on the regulator and is available in a full face scuba mask. Then, the biggest limiter is the scuba tanks. Scuba certified compressors have come down significantly. With a couple of tanks to cycle between, you could provide positive pressure ventilation. The biggest problem then is it is bone dry air. You would have to figure some method of humidifying it in the mask. Yes the wife and I have been discussing this, we are both divers and have several tanks and a couple full face masks

 

[night driver]

Loup, I encourage you to take a REALLY good look at the required controls and variables on a good vent.

Pressure sensed pop-off limits for delivered inhalation are cool UNTIL the vent has to fight lung response compliance (ability to be inflated) at which time it isn't the delivery pressure that should DROP at a pop-off setting but VOLUME has to be limiting variable while the pressure keeps going up. PLUS the timing has to be settable (How long for inspiration, how long for exhalation how long between the two, breaths per minute etc.).

There is also the issue of PEEP and a couple other therapeutic settings as well.

I'm almost sure we have an RT here (perhaps lurking) who can explain what he has to be able to control.

 

[HDC]

Just a thought, since I grew up in that era, Would an Iron lung be modified to work to help a person breath? I know they are no longer made, just a thought.

 

[Old Gray Mare]

i know someone with a family member that received a letter telling them they had to relinquish their cpap machine to be used as a ventilator for coronavirus patients.

yes, it works, but what about the person they are taking the cpap machine from? they need it as well.

So coronavirus victims are more worthy of life than a Cpap user whose life may also depend on the machine?

Why would they have to "relinquish" their Cpap if their insurance which they paid for paid for the machine? Hunybee is your family member residing in a country with socialized medicine?

 

[WalknTrot]

They ARE improvising. Anesthesia ventilators in hospital surgeries are being converted over to pure ventilators with a few minor tweaks.

I just got an email from the Minnesota Veterinary Medical Association last night advising veterinarians to comply promptly to the survey the state is sending around to it's veterinary clinics so to inventory what is available from that angle and others. Yes... a veterinary anesthesia/ventilator for a large companion animal or medium sized livestock would serve for humans just peachy keen.

 

[night driver]

And you can probably dial it DOWN from large livestock, though it'd need to be dialed down a LOT.

Like my brother-in-law doing an arm X-ray with his non-destructive aircraft X-ray machine using a LOT of Kentucky Windage to get the exposure at least close.

 

[LoupGarou]

Loup, I encourage you to take a REALLY good look at the required controls and variables on a good vent.

Pressure sensed pop-off limits for delivered inhalation are cool UNTIL the vent has to fight lung response compliance (ability to be inflated) at which time it isn't the delivery pressure that should DROP at a pop-off setting but VOLUME has to be limiting variable while the pressure keeps going up. PLUS the timing has to be settable (How long for inspiration, how long for exhalation how long between the two, breaths per minute etc.).

There is also the issue of PEEP and a couple other therapeutic settings as well.

I'm almost sure we have an RT here (perhaps lurking) who can explain what he has to be able to control.

Yes, I was planning on getting with a few local doctors and mid levels that understand that end WAY better than I do. I just wanted to get the bulk of the project and coding done before contacting them. I plan to add a lot of sensors to this project, including this little gem: SprintIR®-W 100% CO2 Sensor so that I can watch the blood gass O2 levels via the Pulse Ox, as well as the exhaled CO2 levels to see if things are right or need to be adjusted.

Loup


Loup

 

[teneo]

Speaking as a non-medical person and hopefully non-patient either, vents scare the heck out of me.
My understanding is that a doctor or similarly trained person threads a tube down your throat, past your vocal cords and deep enough to (maybe?) enter the lungs. Then the tube is left down your throat and the other end is hooked up to a machine that artificially inflates the lungs and gives air/oxygen to the patient. All of this is last resort efforts to save a patient who would otherwise die of lack of oxygen. Patients who wake up while intubated freak out from the tube in their throat and may need to be sedated? This is way beyond a CPAP and not surprising that ICUs don’t have a lot of them as it sounds very labor intensive to manage and probably not something that’s easy to improvise. I’ve never had this, has anyone here had it done?

 

[night driver]

If you have had serious surgery you have had it done.

If the patient wakes up either they PLANNED on him being awakened slowly and were there to handle the patient worries **OR** someone screwed up the dosage of Ver- or Pan-curomium, Fentanyl and Versed.

 

[WalknTrot]

I've been seeing preliminary numbers (been watching for these as well as others intently) that 70-80% of people put on ventilator with this virus die. Also seen talk/rumor of instituting universal DNR's if it comes to that. No soup for YOU.

Anyway...in this case, ventilators are last ditch, baby.
Expend your energy on prevention.

 

[Sportsman]

Loup, ,look into APAP, and BiPAP devices as well as generic CPAPs. After a few years of CPAP use requiring multiple sleep studies every so often to determine pressure needed, I was moved to an APAP- Automatic positive airway pressure device. Like a BiPAP that senses when I exhale and pauses for the exhalation, the APAP also ramps up the pressure until it senses it's high enough to move the volume of air and keep the airway open and stays at that pressure value for that breath.

On the CPAP or BPAP, one sets the pressure and that's always the pressure during inhalation. With the APAP, one sets the maximum pressure, and if it senses proper breathing at a lower pressure, it stops well below the max. Mine runs about 70% of the max configured value most of the time.

Once I got the APAP, I haven't had to go through another sleep study. It just works automagically.

Also, most of us that have been on CPAP machines for a few years tend to accumulate an old unit or two. I have a couple. One is in my travel kit (also works of 12 Volts), one in the bedroom, and I'm sure other people have multiple units on hand. They can't be legally purchased without a Rx, but old ones do show up on Craigslist as they make a great low pressure clean-air pump for hobby uses.

The issue of exhalation of fluids isn't as important in a home setting, everyone in the family room is already contaminated. I don't think this option wouldn't be appropriate for a severe case or hospital setting.

I could see this being useful for "home treatment", either medically authorized or DIY for those who are willing to try it as a last resort when that time comes that there are no more hospital rooms available or for milder cases.

Obviously I'm not a doctor and my explanations are not necessarily accurate. But, I've depended upon my APAP machine to keep me breathing all night long for quite a few years.

 

[night driver]

The new "Smart CPAP" do this in a similar fashion, as they ramp up or down during the night. I've awakened at 20 and at 5 on the same night.

 

[night driver]

James Dyson may have beaten you to it, Loup.... Dyson designs ventilator in 10 days, plans to make 15,000 of them to combat pandemic

Gotta read at site. Copy locked.