USMLE Step 1: How to solve V/Q mismatch questions, the A-a gradient
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- Опубликовано: 26 сен 2024
- V/Q mismatch USMLE Step 1 up and down arrows.
Hey guys, in this video I'll show you an easy way to think about V/Q mismatch questions that have those up and down arrows. You have to understand that an A-a gradient is a representative metric of a mismatch between ventilation and perfusion; V/Q mismatch. Keep watching to learn more!
Instagram: / sugarnoor101
Thank you so much- you literally explained most of resp physio in such a short video!
I'm so glad you found it helpful!
Am speechless whatever u touch turns into gold. Best explanation ever for this crap! Now I get it. Thanks lots Noor, and keep up the good work. You deserve an award in my opinion! Now I see why u had a 265, it’s the extra brain u got that most people lack!
Your comments always leave me speechless Solomon. Thank you so much, Looking forward to hearing that you got the score of your dreams! 💪🏻
Best explanation! thank you very much for sharing this.
Glad it was helpful!
proud of you 🔥👏
Thank you so much Malak!! ❤️
Very helpful!
Glad you think so!
Hey, can you make another video explaining the changes of PaO2 , SaO2 and HbO2 with CO and Meth hb? This video is great !
Sure Viraj, will add that to requests
High Yield video! Thank you very much for all the great content! I have a question, Dr. Ryan says that in hypoxemia with a High A-a gradient there is no increase in CO2, how is that possible?
Great video. Thanks!
Anytime!
Uff.... Finally understood this topic.... Thanks alottttt.
You’re welcome I’m glad it helped!
Wonderful, Thank you.
Anytime!💙
الله يرضى عنك
🤲 امين و عنك
Thank you for sharing this 🤩🤩
Glad you liked it!
What’s your concept for the difference between A-a gradient and VQ ratio ? Because if I listen to only the first 2 mins of this video it looks like they’re both the same
A-a gradient is an index of V/Q mismatch. Because there's a disconnect between ventilation [how much air goes in the lungs] and Perfusion [how much of this air reaches the blood], the PAO2 becomes much higher than the PaO2, thus creating a gradient [which is called the A-a gradient]. I hope that makes sense.
@@acingmedicine yes indeed ! Thanks : )
V/Q is focused on the rate for air exchange, please note
What about atelectasis and can you explain DLCO
Atelectasis is a form of shunt due to decreased ventilation in the collapsed alveolus leading to low V/Q ratio
DLCO is the diffusion capacity of Carbon Monoxide. We use this as an index to assess how fast diffusion occurs across the alveolar-capillary barrier. The thicker the barrier, the slower the gas exchange; hence, lower DLCO
Very good video, thank you! May I ask what type of V/Q mismatch we would see in a patient with late stages of COPD? Would we have both increased/decreased and shunt?
With COPD the main problem is ventilation so V/Q is expected to be low resulting in shunt and hypoxemia.
@@acingmedicine Thank you so much Noor. in case we have damaged areas with damaged pulmonary capillaries preventing perfusion, could we also be presented with a high V/Q ratio?
@@octaviablink5706 in that case yeah, that would be a deadspace
Thankkkk uuuuuuuuu❤
you're welcome
Amazing
Thank you Mahmoud!
Does pnemonia cause a shunt or a vq mismatch?
it causes a VQ mismatch where ventilation is lower relative to perfusion. The extreme of the VQ mismatch in pneumonia would be a shunt. for example, If the entire alveolus collapses or is fully filled with pus then this part will be a shunt (as ventilation becomes zero so V/Q is zero)
This is what I have an issue with unfortunately..I associate V/Q mismatch with anything that obstructs the blood flow and I associate the shunt with alveoli obstruction.. how can pneumonia be a v/q mis mismatch if it does not obstruct the blood flow? Thank you so much for helping
Hi Mahmoud, a V/Q mismatch means Ventilation (V) doesn't match Perfusion (Q), whether V is more than Q in case of deadspace or Q is more than V in case of shunt. If V is zero then this is a shunt. If Q is zero then this is a deadspace (wasted ventilation because of no perfusion). However, it's not always a zero value. These are two extremes. it could be reduced but not to the extent of zero. In such a case we call it a mismatch. So, shunt and deadspace are the two extremes of V/Q mismatch.
you mentioned nothing regarding v/q
Can you do a similar video explaining the pathophysiology of the heart and major concept in cardiac physiology, especially pediatric Congenital conditions like tetralogy of Fallot, tricuspid atresia, VSD/ASD etc.? 😮
Alright sure
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