Ventilation Perfusion (VQ) Mismatch Explained Clearly

[@jennifertorresyee7887]

best 14 minutes ever spent! your video summarized in 14 minutes what 2 hrs of ventilation lectures didn't at my school... THANK YOU!!!

[@Medcram]

+Jennifer Torres Glad the video was helpful- thanks for the feedback!

[@jennygonzalez1281]

I'm studying to take my Step one next month and never understood this, after a youtube search on V-Q mismatch I stumbled upon this, thank you so much! It's so clear now, better late than never! :)

[@Medcram]

Jenny Gonzalez Glad we were able to clear up VQ mismatch for you- thanks for the feedback

[@buyornot543]

wow, compared to the PhD teaching at my medschool............ this is pure gold.

[@RavishingSailor]

Thank you so much for all your videos. I'm in my third month as a first year pulmonary/CC fellow and have been using your videos to reinforce concepts that during residency I found very confusing. You have such a talent. Thank you

[@amandanifong7903]

Came here to grasp it for nursing school... And DANG. This was fantastic! Exactly what I needed. Thank you!

[@johnmichael5135]

ur lectures go hand in hand with your picture - you explain so clearly that it is like you are spoonfeeding us the exam answers :) so glad to be subscribed.

[@emilysummer1373]

I have stage IV COPD with VQ mismatch and PH and nobody ever explained what this meant to me. Thank you!! Now I realize why I must keep 02 on always and monitor with pulse oximeter.

[@Cypher1210]

You are a god! Pulmonary Physiology exam coming up & this explained it so much better than my professors rambling!

[@gautammure]

Incredible illustration, Doctor. Bravo! The best I have ever seen. Crisp, eloquent and to the T.

[@shakhirrt5188]

You got a very rare talent that many people dont have..thanks a lot...

[@madheehmohamed9093]

shakhir rt

[@ruannelynch9912]

After reading over the same 3 paragraphs about 4 times in my text book, i bounced up this you tube explanation and i can finally read on. Thank you very much.

[@Medcram]

Ruanne Lynch Good to hear the video made the textbook more readable- thanks for the comment

[@artiepie]

I am a pulmonary hypertension patient and have to have a double lung transplant. This lecture really helped me understand what the docs are talking about when they say my pressures are at certain levels. Thank you

[@lobarita]

ICU nurse here: hard to keep up with, but still very helpful. Thank you guys.

[@jasmac84]

your lectures are great I finally understand so easy to follow... I have been to several lectures on VQ mismatch over the years and could not get my head around it... I listen to your lecture and bang I finally understand it. I'm glad our Uni lecturer suggested to watch your videos..

[@Medcram]

Jason MacAskill Thanks for the feedback- glad the video helped clear things up

[@ashmano23]

Hallelujah !!!!!!!!!!!!!!!! May God bless you million times million. I completely understood the concept, I was so lost before i watched this video. :') Thank you

[@charlotteportzen3337]

You are helping me get through nursing school. Thank you so much for these videos.

[@uzairjavaid219]

Way of your explanation is matchless... A big applause for you

[@Medcram]

Thank you

[@jae89latina]

Blew my mind how simply it was explained! Loved the illistrations

[@ischupak6767]

Legend. If only you were my lecturer! So clear & easy to understand! THANKS A MILLION!!!

[@myprettygirl91]

this is absolutely amazing. I've been trying to understand this concept for literally hours. i get ittttt

[@Medcram]

Thank you for watching!

[@rburdman87]

I was just diagnosed with this today and my head was spinning. Thanks for an easy to understand tutorial.

[@paydenaronson524]

You can not be diagnosed with v/q mismatch... You can be diagnosed with pneumonia or asthma or anything else but not v/q mismatch...

[@rburdman87]

Payden Aronson Interesting...I have documentation stating VQ mismatch from a Cardiologist and a pulmonary team. Had 2 right heart cats done and one was a stress cath ... I am not contradicting you, I don't know enough about it to say who is correct.

[@jennigiatroudakis4240]

Very helpful! But one suggestion: Khan's professors are great at using different colors to help organize paths ways or thought. I would have appreciated that especially in the beginning of the video.

[@singleswomen3929]

Doc am grateful for all your materials.have learnt a lot Anaesthestist resident in Nigeria

[@xinfam0usxplayax]

Wow. ICU presentation today covering MOA hypoxemia. This was the only thing i had trouble explaining. Thank you!!

[@hyrum_abiff4325]

Love the analogy of ' air goes in and out and blood goes round and round' - this is what I jokingly tell people my bachelor of paramedical science taught me. However, essentially keeping a VR and HR going is one very good end goal for treating acute patients, generally speaking. I'm sure you know where I am coming from. Peace

[@gonzojed1]

Straight forward, concise and in layman's terms. Very well done, thank you for your time and effort.

[@captainvdog6871]

Dude! You are a rockstar at explanations!!

[@bluesapphire471]

Words cannot describe how grateful I am for this video! Dr. Seheult did an EXCELLENT job in breaking down the concepts. I am clearly able to grasp the concepts!!

[@hotfoot214]

DR you are a genius.i know understand hypoxema better than after reading all those stuffy texts.thank you

[@jennaisrael7091]

Very Helpful!! I would love to you go through a few more examples of pathology that lead to V/Q mismatch for example when V/Q is low like in bronchospasm or something like COPD/Asthma that affects both lungs in their entirety.

[@Medcram]

+Jenna Israel Thanks for the comment and suggestion!

[@fatboy117]

Finally a well explain concise video with ways to apply this concept

[@prantikachakraborty7330]

you are unique at making difficult concept easier..god bless you

[@Drexelle]

Great video! Now (just to tie it all in) I gotta go find the one where you describe and explain "Shunt". I am a Trauma/Burn ICU RN who loves to understand the rationale behind what we do. Thank you!

[@KBearRawrRawr]

This is a really thorough and clear concise explanation of V/Q mismatch thank you so much!

[@drbirendrakishorenayak1037]

Excellent for the biggner and really very talented explanation which makes easier

[@itsssmenil7287]

thank you! very informative!Please make a video also for respiratory failure.

[@natalielouise2865]

Absolutely awesome! Why can't clinicians just explain it like this? Thank you ever so much for making study easier

[@vinnyfrancio23]

Very good explanation of quite difficult topics for the USMLE step 1. Thank you Sir.

[@Twelvesteps]

Thank you for helping me on my National Respiratory Therapist exam.

[@hillcat2008]

Love this series! I may pass this exam after all!

[@simonbarry6582]

Very good tutorial, very well explained. One thing you do that is soo--o-o often done badly in medical tutorials/discussions is that you have made sure the basic terminology and concepts are explained along the way. Btw this video also taught me PE fundamentals better than anything I've read on PE!

[@Medcram]

+Simon Barry Good to hear- glad this helped in your understanding, and thank you for your topic suggestion. We look at all topic suggestions like yours in planning for new videos

[@judochopthefed]

My understanding of V/Q in the different Lung Zones. where the alveoli get smaller as its gets to the lower zones of the lungs are high V/ Q since the alveoli are smaller and easier to ventilate and perfuse but in the higher zones have larger alveoli has less V/Q since the alveoli are larger in the higher zones of the lungs. Your video showed me a total opposite of what I understand or think I remember with respect the V/Q in the Alveoli in the different Lung Zones.

[@padersam2012]

thank you for such a clear explanation of V/Q mismatch

[@Shaf2010]

Thank you so much.For the first time,I can say that I understand Hypoxemia.

[@marygraham8120]

@Tye, Aa refers to alveolar-arterial gradient and the concentration of oxygen of both areas.

[@cocokrisp8967]

Fabulous! great visuals and clear instruction!

[@Hernandez877]

Thank you so much. My professor didnt even let me know that Q was perfusion

[@hornet011]

One thing, V/Q mismatch doesn't necessary mean that part of lung has lower rate and other part higher than usual, it means that V/Q is different than normal for lungs. In pneumonia for example there aren't pulmonary segments with higher ratio. Only lower, and result is hypoxic blood.

[@MijntjeV]

Wauw, this is soooo incredibly helpful! My test is tomorrow and I have higher hopes now haha! Thanks a lot!! X

[@leiying]

Great explanation! Just need some clarification. I was taught that: - in lobar pneumonia, a portion of the lung has gunk in it and therefore is effectively a partial shunt (for that part of the lung) - V/Q ratio is very low - in pulmonary embolism, a portion of the lung cannot not be perfused and therefore is effectively in dead space ventilation (for that part of the lung) - V/Q ratio is very high SO when you say breathing 100% oxygen will correct a decreased arterial PO2 caused by V/Q mismatch but NOT shunt, are you referring to the shunt as being a very large shunt that blocks off an entire lung like widespread "white out" pneumonia? Is there a gradient for when V/Q mismatch becomes a complete shunt or complete dead space when the V/Q ratio reaches extremes?

[@rjt6765]

I believe the principle he is speaking to is blood flow through a shunt, either from a pneumonia (blocked alveoli with mucus) or physiologic (like deoxygenated blood from the lung parenchyma) will not be exposed to oxygen at all (very low V/no change in Q). Increasing the PiO2 will have no effect on shunted blood because it is never within diffusion distance of blood. Hope this helps.

[@cnmacias1]

You explained things wonderfully! Thank you for making this topic simpler for me.

[@skizaftis]

Fantastic explanation. You are doing great job!

[@danielalexander8643]

very good explanation.. V/Q mismatch isn't difficult again with this lecture..

[@7r1n3santiago]

great video and easy to understand! please keep posting

[@hasanabad9141]

Thank you for your video. I just have one question regarding pneumonia and pulmonary edema, i.e. In those states, is it that you have increased fluid in the alveoli resulting in impaired ventilation but normal perfusion, creating an intrapulmonary shunt? So why would supplemental oxygen improve oxygen status in this case? Thank you in advance.

[@elizabethallen3751]

These have been great, thanks for posting. Everything is clearer now!

[@aldys2005]

You have a great way of teaching. Simple and precise! Thank you!

[@rody2022]

Thank you so much for your clear explanation. I finally understand V/Q balance and imbalance, yay!

[@Medcram]

Roddy Gee Good to hear- Thanks for the comment!

[@JelliBaby780]

Lifesaver please continue doing this!!!!

[@Medcram]

+JelliBaby780 Thanks! More videos coming soon

[@Medcram]

See the whole series at www.medcram.com along with other top quality videos including reviews in pulmonary, cardiology, infectious disease, and hematology!

[@cherie-chufeiwong2212]

@12:35 You said that blood will go from high V/Q to low V/Q area. But I think it should be opposite. Decreasing ventilation and increasing perfusion will cause the terminal arterioles constrict and redirect blood to the respiratory area where PO2 is high. Therefore, the blood should go from low V/Q area to high V/Q area.

[@Medcram]

+Shirley King Thanks for commenting. What I was trying to communicate was that when there is a physicial obstruction in the pulmonary artery, this is going to cause blood to go from that area to anywhere else it can. Because of this it will cause an area of low perfusion to the affected area (high V/Q) and an area of high perfusion to everywhere esle (low V/Q).

[@laryssablunt8299]

GREAT demo! Clear and informative!

[@sanj5026]

Roger. Thank you for all the videos. Please keep them coming!! Very helpful for a respiratory therapist student that's just entering his/her clinical practice :D

[@chrisjauregui7308]

Great material, simple to understand.. thank you

[@Medcram]

Chris Jauregui Thank you- glad it was helpful

[@simonl6151]

Very helpful thank you! Luckily I found this video. Have physiology test tomorrow :)

[@1joseoliveira]

Why does VQ mismatch apply in Pulmonary Emboli? If there isn't any blood flow to that section of the lung shouldn't it be marked as dead space? Earlier in the video you said VQ mismatch works only for lung that is both perfused and ventilated (no matter the balance or mismatch between them).

[@kasahunbentimerga3006]

You are my favorite, as usual!

[@DaNamesScruffy]

Very good video, but would APO be another cause of V/Q mismatch

[@jamalulazizi_MD]

Great lecture. Would like a topic "cardiopulmonary exercise testing Explained Clearly. Tq

[@dlong9562]

Made it very easy to follow and understand. Thanks

[@Medcram]

D Long thanks for the feedback- glad the video helped

[@dropsdrops]

Could you please explain why hypoventilation is not considered a type of a V/Q mismatch (low V/Q) if there is lowered alveolar ventilation (V) with normal perfusion (Q) in this condition ? (e.g. the alveolar ventilation 2,5 l/min and the perfusion 5 l/min -> V/Q = 0,5) This is the thing I cannot understand so i'd be grateful for some clarification on this matter. (sorry for posting this question under your hypoventilation lecture too :) )

[@katyaa7865]

Great video has made it all a bit clearer!

[@kristinruttan5451]

great explanation! this made V/Q very easy to understand. thank you!

[@pallavirao4127]

Beautifully explained.. Thank you

[@nicollepicton3208]

Thank you! This is super helpful.

[@patppiot]

Great! Any cardio lectures?

[@timhardcastle5428]

Resp test next wednesday.......thank you from New Zealand :)

[@summerbreezenight]

I have a question: Isn't the blood sent to alveoli that are better ventilated, so the perfusion increase in the area? Thank you for answering.

[@sofiauz]

great videos! would be interesting to watch EVLP related topics

[@Medcram]

sofia uz Thanks for the suggestion

[@lutfinurfarid9176]

Very helpful, the explanation is very clear. Thanks!

[@kheeters]

this was incredibly helpful!! one topic of interest (may already be covered, havent looked to see yet) differentiating PA02 from Pa02 from percent saturation from Fi02, and the different pathologies impacting all of these values (CO poisoning, altitude sickness, methemglobinemia, etc)

[@Ghadeer88KSA]

Thank you for the great and easy demonstration that was very interesting .. You made every's clear so far .. Thanks again

[@kevinfacemyer7796]

Perhaps a "clarification" is needed to explain the mechanism for why mismatch causes hypoxemia. When two blood samples are mixed, each with a known condition of SaO2, Hb, and PaO2, the oxygenation of the mixed blood is defined by the oxygen content (CaO2 in mLO2 per dL). CaO2 is the concentration of total O2 in the sample. When mixing two samples, the calculation is (CaO21 x Vol1 + CaO22 x Vol2)/ (Vol 1 + Vol 2). From the oxygen content equation, most of the CaO2 is due to the SaO2 and the [Hb], not the PaO2. In the case here, the Hb is constant. So the major determinant of the differences in CaO2 between the two blood samples is the SaO2. Therefore, the CaO2 of the mixed blood can be estimated by (SaO21 x vol1 +SaO22 x vol2)/(vol1 + vol2). Another way of saying this is that the O2 composition of two samples of blood after mixing is the flow-weighted average of the two SaO2s. Consider the case where the two volumes (perfusion or flow) of the two respiratory units happen to be the same, but the ventilation to each is different, there will be a V/Q mismatch. Each unit will have blood leaving it with a different SaO2. The resulting mixture of the two will be defined exactly by the average of the two SaO2s (because the two volumes (perfusion rates) are the same). So to make the general comment that the mixture will NOT be the average of the two SaO2s, as did Dr. Seheult, does not lead to any understanding of the mechanism involved and is not always correct! Another point I can make is that this video does not explain why there would be a P(A-a) difference in a V/Q mismatch situation. That requires an understanding of the relationship between SaO2 and PaO2, and the shape of the Hb-O2 dissociation curve. The curve is very flat at high PaO2 region, so the PaO2 can drop precipitously with very little change in SaO2. So when you get that flow-weighted average of the two SaO2s, even if if is only depressed a little bit by the poorly oxygenated unit, the end result is a large decrement in the PO2, much more than if you were to take the average PaO2. If the PaO2 is much lower, this will lead to the A-a difference being much larger. The major point here is students should understand that the CaO2 is what defines whether or not your patient has enough O2. Some people define hypoxemia as low PaO2 for a persons age, but a better definition is a lower than normal CaO2 of the blood.

[@bdbaker4493]

so how much should an EMT know about V/Q? the Emergency Care book barely mentions it but I find it hard to follow in the video

[@DanielWilliamHancock]

Thanks, you made it very simple, my lecture was shocking in comparison

[@rizkiadrianhakim]

Very clear explanation, thanks !

[@markprice9726]

Hi MedCram, I'm almost certain you get asked this all the time but what is the name of the whiteboard software are you running to create videos like this one?

[@maveille]

Extremely helpful and concise. Thank you very much!

[@AlexTarazona]

you did a better job than my patho teacher

[@IndyaBeerens]

from the bottom of my heart..... thank you

[@Mregmee]

Excellent video, very helpful

[@Medcram]

Manoj Regmi Thank you for the comment

[@jts3793]

I am still new to this but wouldn't pneumonia be grouped under the shunt subcategory since the inflammatory mediators cause vasodilation even though there is consolidation hence no ventilation?

[@lrybal]

Thank you this is a great video series. What if you are not given enough information on a question, but have to differentiate between shunting and V/Q mismatch. ie a patient is in a 55% oxyhood..ventilating fine (Co2 32 torr), but oxygenating poorly (Pa02 45 torr).Would you assume this is V/Q mismatch or shunt? Would this be considered ventilation without perfusion?It would be helpful to know the response to 100% Fio2. How would you answer this? Any help offered would be appreciated.Thanks

[@m33rebus]

Loving your videos, it made applications of medicine much more easier to understand! Also, just wondering, how does hypocapnia play out in the compensating of this situation?

[@11zen45]

Thank you sooooo much. Bless you. I appreciated your simple & clear explanation.

[@Medcram]

+Vanessa James Thank you for the feedback

[@yellobra6452]

Wonderful explanation ++ Thank you very much!! (from France)

[@Medcram]

+Yellobra Merci beaucoup!

[@craigkalin9517]

Can you do a video on V-V ECMO dealing with pO2 and Sats in the systemic circulation

[@rakeshkiru1232]

firstly thanks so much for such a nice video . just one question is there chance of V/Q mismatch in case of hemothorax ?

[@ahmedghanem1983]

what i know is that both shunting and dead space are disorders of V\Q mismatch and both resulting in hypoxemia but dead space effect ( ^ V\Q mismatch) is responding to 100% O2 therapy while shunting effect (low V\Q mismatch) is not. also, hypercapnia is more evident in high V\Q mismatch (dead space ) than low V\Q mismatch (shunting) greetings,

[@valeriea4453]

Can VQ mismatch be caused by a lower amount of ventilation (though not low enough to be a shunt) rather than an increased perfusion in one area?