[irdevanand]

Requesting doctors in team-bhp to spare a moment and share some light on oxygen concentrators. Have the following questions in mind. Kindly excuse me for taking your precious time away but i think this would also be helpful to many. Thanks a ton in advance


1. What is LPM ? My dad was given 6 LPM oxygen when he was admitted in hospital. Which means 6 liters per minute of O2. That means for 24 hours he should have inhaled 6liters per min * 60 mins * 24 hours = 60480 liters of oxygen. Is that right? But the cylinder they used in the hospital which is about my height is about 350 liters size. How is that a 350 liter cylinder can give 60k liter oxygen? What am i missing? They changed the cylinder only once a day.

2. Can a covid patient use oxygen concentrator to surive? Assuming there are no beds in hospitals can we use an oxygen concentrator + home nurse/doctor to give steroids and other treatments at home? Will it work? If yes will a 5LPM machine suffice? Or do we need 10LPM? Doctors round table in india today has suggested that 5LPM is not enough as they cant keep 94% continously.

3. Nidek, Philips, Oxymed - what are the safe and reliable brands? I am seeing new brands in amazon now. https://www.amazon.in/Concentrator-w...dp/B093LTTW86/ retails for 80k. I spoke to them. 10 months warranty. Made in china. Zero reviews in amazon. But looks like amazon has booked 800 units in bulk. What is your opinion about such models?

4. Oxygen Concentration:30%-93% (Adjustable) - what does this mean? The above company person mentioned that if i want 93% oxygen concentration i have to keep flow as 1L and if i keep flow as 7L oxygen concentration will become 30%. What is the meaning of this? For covid patient needs maximum concentration at maximum flow right? Like 93% and 5LPM?

5.From a post covid scearnio will these machines be useful for elders who have cardiac problems, parkinsons, or any other problems? Assuming we spend 1lakh on such a device and if it can help our parents for several years then there is no second thought about buying it. Might help some relative during covid and once it is over can be useful for parents. In china i heard that people above 65 use such devices normally. Is that true?

6. Customs duty is waived for such devices now. But any reliable websites from where we can order such devices from other countries?

Links i have collected so far
- Best 5 LPM oxygen concentrators

https://youtu.be/DgYjPQEw5JE

- Nidek the best brand outthere https://www.amazon.in/Nidek-Nuvo-10-...dp/B07KYS82BT/
- Oxymed https://www.amazon.in/OXYMED-OXYGEN-.../dp/B08JCMSKKQ
-

https://youtu.be/zGOw13BZKv0

Regards
Dev

[drrajasaravanan]

Originally Posted by irdevanand

Requesting doctors in team-bhp to spare a moment and share some light on oxygen concentrators.

Hi,
Kindly go through the attachment which will provide a brief idea of how and when you should be looking for Oxygen concentrator for home use.
Their is a very narrow window for actually utilizing the oxygen concentrator and it has to be decided case by case. Unless a medical professional reviews and of opinion that your elderly folks need long term oxygen support I urge you not to consider such a equipment. Though this is NHS standard it would be similar to our situation. To add to this we have discharged umpteen number of patients and yet to consider asking them to purchase concentrators.

[Trust_In_Thrust]

My dad age 67 is a Diabetic with three times insulin per day. He got infected on 16th April , two day later my mom age 65 and next day me age 39. We all three are under recovery and my dad and mom sp02 was hovering around 90 for many days. We are extremely lucky we have no loss. There is no support from Delhi government and we are lucky to have managed it with home isolation with lot of prone position time. My dad was feeling very low and I was very down so I said I can drive down to every hospital on a route to next state to next state until we find a ICU bed and hopefully you can endure it. We didnot need to take that travel but I know few who have travelled thousands of kms for a ICU bed from Delhi . One night I could not sleep with the thought what if oxygen dips below 90 and I for the fear of what if I had ordered oxygen concentrator from Tushti store who popped on Google shopping. It costed me 1.25lacs with upto 8ltrs per min and dual outlet . I was told delivery by 6th May .


Apart from routine RTpcr , ESR , CRP test D Dimer test was done on 1st May for dad and Mom. Value was 950 and 906 for mom and dad respectively. Family doc asked administration of 4 injection each of blood thinner for which I travelled for two days in every chemist shop I could find in Delhi. I am lucky I found 8 x of these and have been able to given it to my mom and dad.

I donot know what will work or what will not but I pray no-one has to go through the helplessness feeling that I endured for nearly 15 days .

[irdevanand]

Originally Posted by drrajasaravanan

Hi,
Kindly go through the attachment which will provide a brief idea of how and when you should be looking for Oxygen concentrator for home use.
Their is a very narrow window for actually utilising the oxygen concentrator and it has to be decided case by case. Unless a medical professional reviews and of opinion that your elderly folks need long term oxygen support I urge you not to consider such a equipment. Though this is NHS standard it would be similar to our situation. To add to this we have discharged umpteen number of patients and yet to consider asking them to purchase concentrators.

Thanks a lot Doc. Good read. Got some of my doubts clarified from that pdf. Especially on liquid oxygen litres in the cylinder vs O2 flow litres/min. A 30/40 litre cylinder can give 2litres/min for 8-10 days. So essentially 1 litre of liquid in the cylinder translates to 500-600 litres of O2.

Regarding concentrator for my Dad. By looking at the document. Looks like my dad might not be needing this equipment as long as his SP02 stays above 88. Regarding how his other ailments are connected to oxygen therapy i need to investigate further. His SpO2 right now is 94. So if i buy, it will be more of buying the equipment and keeping it ready in case any one else in the extended family / friends circle needs it for covid just like what the gentleman from Delhi reported in this thread in the next page. Will continue my search in this angle for now.

Thanks again Doc
Dev

[GTO]

Guys, moving out the oxygen concentrator posts to a new thread in case it helps other BHPians (new thread = 1000X easier to find via forum search or Google).

[irdevanand]

Originally Posted by irdevanand

4. Oxygen Concentration:30%-93% (Adjustable) - what does this mean? The above company person mentioned that if i want 93% oxygen concentration i have to keep flow as 1L and if i keep flow as 7L oxygen concentration will become 30%. What is the meaning of this? For covid patient needs maximum concentration at maximum flow right? Like 93% and 5LPM?

Got the answer for the above point from a Nidek demo video. When you buy an oxygen concentrator for covid make sure it has the ability to give maximum oxygen concentration/purity at higher flow rate. For example see the video below. In 3:07 mins you can see the machine giving out 95% O2 purity at 7.6 LPM. This is great. This is what can match hospital level o2 for covid patients.

https://youtu.be/HNlO5YZpI0w

[dgoyle]

Originally Posted by irdevanand

Thanks a lot Doc. Good read. Got some of my doubts clarified from that pdf. Especially on liquid oxygen litres in the cylinder vs O2 flow litres/min. A 30/40 litre cylinder can give 2litres/min for 8-10 days. So essentially 1 litre of liquid in the cylinder translates to 500-600 litres of O2.

Please note: The cylinder for home use in India does not contain liquid oxygen. It has gaseous oxygen at 2000psi pressure (138 bar) and is regulated (through the pressure regulator) to bring the pressure down to 50 PSI (3,5 bar) before the oxygen is fed to the flow meter (the device where you note the flow rate as 2 or 6 or 10 liters per minute) and thereafter downstream to the patient.

There is a pressure monitor that is fixed to the cylinder which measures the pressure of gas in the cylinder. As the gas is used up, the pressure in the cylinder reduces. This pressure reading can be used to calculate the cylinder duration.
(Current Cylinder Pressure × Conversion factor) /Flow (L/min) =
Duration of flow (min)
e.g:
(A) 1000 psi x .28 (for a 625 lt cylinder) / 10 L/min = 28 minutes
(B) 2000 psi x .16 (for a 350 lt cylinder) / 2 L/min = 160 min
*the conversion factor for a 350 ltr oxygen cylinder is 0.16 and for 660 ltr cylinder is .28
Conversion Factor is calculated by dividing the max volume by the
Max pressure.

This is a rough guide we use.
Hope this helps.

[lemedico]

The most important fact is to understand COVID-19 patients may require 90% Oxygen concentration at 1 to 5 litres per minute (lpm) flow and above 10 lpm when they are suffering from acute respiratory discomfort.

90% oxygen concentration is the most important point here.

1. We can classify oxygen concentrators into small (5 to 10 kg) oxygen concentrator suitable for COPD (Chronic Obstructive Pulmonary Disease) patients, medium (15 to 19kg) and large (20kg and above) oxygen concentrators are suitable for critical care and for COVID-19 patients.

2. Small oxygen concentrators can have options from 1 lpm to 9 lpm flow but this does not mean you get 90% oxygen at a higher flow like at 5 lpm. In small oxygen concentrators, 90% oxygen concentration is achieved only at lower flows of 1 lpm to 2 lpm. At higher flows, the oxygen concentration drops to 30% as you increase the rate. This is adequate for COPD patients but not for COVID-19 patients.

3. Check the specs of the oxygen concentrator and if you see 90% - 30% or ( 1L/min, 2L/min) means 90% oxygen is available only at 1 lpm or 2 lpm respectively and on higher flow rates, the oxygen drops to 30%. The air we breathe is with 21 % oxygen. So small (5kg to 10kg) oxygen concentrators at higher flow rates give an output of 21 to 30% oxygen means it's mostly blowing air.

4. Weight is the best indicator to understand the oxygen production capacity.

A 5kg to 10kg oxygen concentrator means it has a small compressor, which will only manage to give an output of 90% oxygen at 1 lpm to 2 lpm.

A 15kg to 19kg oxygen concentrator will have a compressor that can easily give an output of 90% oxygen at flows from 1 lpm to 5 lpm (Ideal for COVID-19 patients and critical care patients)

A 20 kg and above oxygen concentrator will have a large compressor, which can give an output of 90% oxygen from 1 lpm to 10 pm. (Ideal for COVID-19 patients and critical care patients and for two patients to use the same machine with accessories)

Please do not only see the output flow of an oxygen concentrator like 5 lpm, 10 lpm or so on. The most important thing is to make sure you get 90% oxygen at the highest flow level.

For a small family with no senior citizens, a 5 lpm at 90% oxygen concentration should be adequate.

For 2 senior citizens or for a big family 10 lpm at 90% oxygen concentration should be good enough as it can support 2 patients at once if the need arises.

Please read the specifications properly, and if required please ask your supplier to show you the oxygen output on an oxygen analyzer at the higher flow rate of 5 lpm or 10 lpm.

POINTS TO BE NOTED:
1. You'll need to crack a window open to allow fresh air to enter the room, as the oxygen would soon deplete in a closed room. -VERY IMPORTANT

2. Do not consider these devices are the ultimate treatment for breathlessness. If one remains unwell, please refrain from consulting the University of Whatsapp, and contact a doctor for further advice. Which sadly for most would be hospitalisation and intensive care.- VERY IMPORTANT

3. Regarding the pricing, in today's Times of India(8th May 2021), Phillips India has released a statement clarifying they are not responsible for the various other no-brand devices being sold under their false name. And also the cost of their device is around the MRP of Rs. 68,000.

4. I am a frontline doctor all throughout the pandemic, serving the patients (In Delhi) directly in the wards since March 2020. I am up to date with the guidelines and treatment strategies. I have recently been felicitated for my services by my alma-mater in the UK. Please feel free to consult me if anyone is unwell and requires a targeted management. I'd include my number here if the admins give me a green light.

Please do NOT copy-paste prescriptions for each other, it is dangerous and an incomplete management of one's condition.

take care

[dgoyle]

The two pressure regulators are seen. One shows the pressure of the cylinder (right) and the other (left) shows the pressure of the gas being supplied to the patient

[shashi792]

I understand every patient and every scenario is different.

I would suggest a page similar to the 'what car' be created and TBhp doctors/frontline workers provide only the basic instructions to mildly symptomatic/asymptomatic patients or their caretakers.

Eg.
Patient ID : (Just a serial number)
Patient Place:
Symptoms:
O2 Level:
Current basic parameters:
Food Requirement:
Current status:

Plus some phone numbers (of frontline workers) to talk to during the panic mode.
I think we need to shift gears for now.

[lemedico]

Originally Posted by shashi792

Plus some phone numbers (of frontline workers) to talk to during the panic mode.
I think we need to shift gears for now.

Count me in, are we permitted to write phone numbers on the forum?

[docsr]

Oxygen Concentrators concentrate ambient air by removing nitrogen by adsorption and thereby increase concentration of Oxygen in air that is output. As the air we breathe has about 21% oxygen and about 70% nitrogen, removing nitrogen increases the portion of oxygen in the output.
The efficiency of this is flow dependent - higher the flow across the adsorption medium, lower is the efficiency and hence the percentage of oxygen in the output air falls as the flow increases. While most concentrators should provide 80-90% concentration of oxygen at flows of 1-2L/min, this concentration rapidly falls as the flow rates increase. Oxygen concentrators have been used for a very long time in home care of patients with chronic lung disease such as COPD etc.

It's use in the COVID situation was born more out of desperation than any specific design. Due the changes in the lungs due to the COVID infection, they are no longer supple and are difficult to inflate (poorly compliant). Hence progressively higher and higher are pressure is required to expand the lungs and get air into them. This can be compensated for, in early cases, by giving high flows of air, that to an extent increases the pressure of air delivery and helps expand the lungs. Eventually though, if the problem continues, a positive pressure is require to open the lungs and the patient ends up needing a ventilator.

The increased oxygen concentration in the inspired air is because the lung membranes become less porous to oxygen because of fluid collecting within it due to the COVID infection. Thus higher oxygen proportion is required to get more oxygen into the blood (a factor measured using pulse oximeter). So COVID patients need BOTH a high flow (and higher pressure) and high oxygen concentration. Now you can see why traditional concentrators are only a stop gap.

The market is literally flooded with very overpriced devices at present. However, there is really no standardisation and you really do not know whether the patient is getting what you are setting the machine to deliver. Quite likely, not!

Originally Posted by irdevanand

2. Can a covid patient use oxygen concentrator to surive? Assuming there are no beds in hospitals can we use an oxygen concentrator + home nurse/doctor to give steroids and other treatments at home? Will it work? If yes will a 5LPM machine suffice? Or do we need 10LPM? Doctors round table in india today has suggested that 5LPM is not enough as they cant keep 94% continously.

Yes, there are several home care based companies that are lending machines and nurses to set up such care facilities are home or in apartment complexes. They definitely offer residents of such complexes some mental security, some buffer.But if someone is truly sick, these kind of setups will be of limited use. Ultimately, the patient will require a hospital!

Using medications such as steroids, oxygen cylinders etc without adequate supervision and care are potentially very very dangerous. So please do not self medicate. Most large hospitals today are offering web based consultation and medical supervision, and this is the optimal first choice.

Unfortunately , there is only so much DIY one can do in this situation. Public pressure on the administration and government to do their jobs is vital.

[kaps454]

Originally Posted by irdevanand

Requesting doctors in team-bhp to spare a moment and share some light on oxygen concentrators. Have the following questions in mind. Kindly excuse me for taking your precious time away but i think this would also be helpful to many. Thanks a ton in advance


1. What is LPM ? My dad was given 6 LPM oxygen when he was admitted in hospital. Which means 6 liters per minute of O2. That means for 24 hours he should have inhaled 6liters per min * 60 mins * 24 hours = 60480 liters of oxygen. Is that right? But the cylinder they used in the hospital which is about my height is about 350 liters size. How is that a 350 liter cylinder can give 60k liter oxygen? What am i missing? They changed the cylinder only once a day.

The volume discrepancy is easy to explain and you can use Boyle's law (high school physics) to go about. It gives a rough idea as oxygen is not an ideal gas. Not sure which cylinder has 350 L as intrinsic volume, measured by volume of water, as different gases occupy different volumes at similar pressure.
As for treating a covid patient, try to find a bed in a hospital because the patient needs medical supervision. Oxygen concentrators can buy one some time I guess but not a panacea (infact nothing is). Also cylinders are risky to keep at home, one topples over and you have had it. Oxygen cylinders are usually filled till a pressure of 1600 - 1900 psig. They have a service pressure of around 2200 psig. So it is a missile waiting to be launched.

[De-Veer]

There has been a general confusion in the capacity of the oxygen cylinders. As someone involved in importing these right now, I have gone through the ISO standard ratings and talked with multiple ICU attendents and doctors.

The 10l and 40l, grade b and grade D type cylinders are the most common in India. The 10l and 40l is the maximum water volume available in the cylinder. This is at 1 bar. The cylinders for oxygen are rated at 150 bar, currently being filled at ~140 bar. At that pressure, we are able to store 164L of oxygen in a 10l cylinder. This is fine for personal use of a patient in transport but not for critical patients. A jumbo d type can hold 680l of oxygen.

Note: will add more information at a convenient time

[irdevanand]

Originally Posted by lemedico

4. Weight is the best indicator to understand the oxygen production capacity.
A 5kg to 10kg oxygen concentrator means it has a small compressor, which will only manage to give an output of 90% oxygen at 1 lpm to 2 lpm. A 15kg to 19kg oxygen concentrator will have a compressor that can easily give an output of 90% oxygen at flows from 1 lpm to 5 lpm (Ideal for COVID-19 patients and critical care patients) A 20 kg and above oxygen concentrator will have a large compressor, which can give an output of 90% oxygen from 1 lpm to 10 pm. (Ideal for COVID-19 patients and critical care patients and for two patients to use the same machine with accessories)

Thanks a lot Doctor for giving everybody the simplest indicator to look for in a O2 concentrator. Much needed information.

Originally Posted by lemedico

4. I am a frontline doctor all throughout the pandemic, serving the patients (In Delhi) directly in the wards since March 2020. I am up to date with the guidelines and treatment strategies. I have recently been felicitated for my services by my alma-mater in the UK. Please feel free to consult me if anyone is unwell and requires a targeted management. I'd include my number here if the admins give me a green light.

Thanks a lot for your service to our country Sir and thanks a lot for taking time to reply.