Reiner Wilhelms-Tricarico The PaO2 is typically measured by drawing and analyzing a sample of arterial blood in a test known as an arterial blood gas (ABG).
TheAncientScholar Thanks for a quick answer. The reason I asked this question is because often oxygen saturation levels are just measured by these little clamps one can stick on a finger. And apparently there was this problem that often people had Covid19 and showed values of 60 percent or less on their oximeters, but felt basically fine even though they had dangerously low levels of oxygen. So I was wondering if these oximeters might not really show the right numbers when you’re infected with this virus. Many people have these clamps now at home and rely on them. And of course they can’t validate the measurements by ABG - which requires a real lab. Since the measurements with those hand clips are indirectly based on spectral properties of blood that change with oxygenation (comparing two spectral lines) I wondered if there could be other changes in the blood due to the infection that might influence spectral changes of blood by causes other than change of oxygen concentrations. I know, it’s a wild speculation.
For non-invasive ventilation you can count P/F ratio... First get paO2... I do that by fitting pulseoxi meter and convert SpO2 to PaO2 chart (and hope my machine is functioning fine).. for FiO2 = O2 in inspired air/ minute ventilation. Count minute venti= Respi. Rate x tidal volume...[ say rr is 25/minute and tidal volume is assumed in between 500-750...say its 500ml...so Minute venti= 25*0.5=12.5L/min...means patients is breathing total 12.5 L of air per minute,] Now for O2 in that air..look at flow meter above patient and it says he is getting 5L .....so 5L is 100% O2 every minute...so out of that 12.5L.. = (5 * 1.0) + (7.2 * 0.21) = 6.5 Now your patients FiO2= 6.5/12.5= 0.52... And patients pulse oxi is showing 90% spO2...which is converted to PiO2 of = 58 mmHg.. P/F ratio= 58/0.52= 111....means you need to do something immediately.
30 minutes in class for the professor to get to the point of this video, which took you only 1 min 30 sec.. Thanks for the video.
God, this was so helpful. You made it very understandable for me.
Thank you so much for the great lecture.
"Thanks for hanging in there guys" Love it
very well explained and simply
Thank you, sir!
Very comprehensive
Thanks!
Excellent explanation, it was very helpful for my critical care class
T treestu
Thank you very much sir🙏🏼
very nice
Nice explanation
subscribed
Best
How do you measure partial pressure of O2 , I.e. PaO2 in a clinical setting, that is in an ICU for example?
Reiner Wilhelms-Tricarico The PaO2 is typically measured by drawing and analyzing a sample of arterial blood in a test known as an arterial blood gas (ABG).
TheAncientScholar Thanks for a quick answer. The reason I asked this question is because often oxygen saturation levels are just measured by these little clamps one can stick on a finger. And apparently there was this problem that often people had Covid19 and showed values of 60 percent or less on their oximeters, but felt basically fine even though they had dangerously low levels of oxygen. So I was wondering if these oximeters might not really show the right numbers when you’re infected with this virus. Many people have these clamps now at home and rely on them. And of course they can’t validate the measurements by ABG - which requires a real lab. Since the measurements with those hand clips are indirectly based on spectral properties of blood that change with oxygenation (comparing two spectral lines) I wondered if there could be other changes in the blood due to the infection that might influence spectral changes of blood by causes other than change of oxygen concentrations. I know, it’s a wild speculation.
@@TheAncientScholar But ABGs often don't include the pAO2! How do you get this figure???
How to caluculate FiO2 if patient is on a NRB mask/Nasal cannula?
For non-invasive ventilation you can count P/F ratio...
First get paO2... I do that by fitting pulseoxi meter and convert SpO2 to PaO2 chart (and hope my machine is functioning fine)..
for FiO2 = O2 in inspired air/ minute ventilation.
Count minute venti= Respi. Rate x tidal volume...[ say rr is 25/minute and tidal volume is assumed in between 500-750...say its 500ml...so Minute venti= 25*0.5=12.5L/min...means patients is breathing total 12.5 L of air per minute,]
Now for O2 in that air..look at flow meter above patient and it says he is getting 5L .....so 5L is 100% O2 every minute...so out of that 12.5L..
= (5 * 1.0) + (7.2 * 0.21) = 6.5
Now your patients FiO2= 6.5/12.5= 0.52...
And patients pulse oxi is showing 90% spO2...which is converted to PiO2 of = 58 mmHg..
P/F ratio= 58/0.52= 111....means you need to do something immediately.
th-cam.com/video/zoGK2AEKbK0/w-d-xo.html