Pulmonary Embolism Explained Clearly – Risk factors, Pathophysiology, DVT, Treatment

okay well welcome to another med cram lecture today we're going to talk about pulmonary embolism and specifically we're going to talk about the epidemiology and also the risk factors in the next lectures we'll talk about other things for instance the diagnosis and treatment but let's talk about pulmonary embolism its epidemiology risk factors things of that nature first of all what is a pulmonary embolism well to look at this we've got to look at the relationship between the heart and the lungs as we know we've got the heart which pumps blood to the lungs and also the left side which pumps blood to the rest of the body and in each side we've got the lungs which sits on the left and the right now of course we know that the venous system not only from the bottom but also from the top drains into the right side of the heart and from there from the right atrium it goes to the right ventricle and the right ventricle pumps blood specifically to the lungs because of this any blood clot in any vein is eventually going to end its way up if it breaks forth into the right side now because of that the right side of the heart pumps this clot into the pulmonary arteries and because the pulmonary artery gets smaller and smaller and smaller and smaller that blood clot is going to get caught in the lungs and get lodged and that's what's known as a pulmonary embolism now typically because blood flow typically goes more to the lower part of the lung than it does the upper part of the lung and that's a result of gravity more or less because of this you're going to see more pulmonary embolisms in the lower portion of the lungs and less in the upper of course it can happen anywhere but just as a general rule since more blood flow goes to the lower portion of the lungs you're going to tend to see more blood clots lodging in the lower portion of the lungs now is there any predilection as to what side they tend to go on now the answer is not really but it's possible for it to actually get stuck in the middle where the pulmonary artery branches that's known as a saddle embolus and that can be fatal obviously because of the large amount of blood flow that gets disturbed and that type of pulmonary embolism okay so what is the incidence of pulmonary embolism believe it or not it's about 600,000 people per year get a pulmonary embolism and this results in anywhere between 50,000 and 200,000 deaths per year that's a lot of people and so I think this is an important diagnosis to talk about okay now that you know what they are let's talk a little bit about them in general first of all we miss them a lot what do I mean by that we miss them a lot they happen a lot in the emergency room and in the hospital and we fail to pick them up because we don't realize this and how do we know that we miss them a lot because of autopsies okay we see them on autopsies and we didn't even think that the patient would have had them we also test for these a lot and what happens is they're negative so we think that they're there and we test and they don't turn out to be positive and in other cases we don't even think about them and on autopsy we see pulmonary embolism what does that tell you tells you that we're not doing a good job of picking these things up and it's probably one of the most misdiagnosis in the hospital where do these things come from well most pulmonary embolisms are from deep venous thrombosis and most pulmonary embolisms from deep venous thrombosis come from the lower extremities above the knee so they're in the legs above the knee that's where we need to start looking for these things so well what is the pathophysiology the pathophysiology specifically is is that these blood clots form down in the legs because of a number of possible risk factors they break off they go up the inferior vena cava to the right atrium to the right ventricle and then they lodge themselves in the lungs now what happens there when the blood cut gets lodged in the pulmonary artery there is no more perfusion to that area of the lung and so what you're getting there is ventilation without perfusion and that is basically dead space and more forward is that the blood that should have gone to that area that has to get diverted to other areas of the lung and then you get an increased flow of blood to the other areas and so the major mechanism is VQ mismatch if you have any questions about the mechanism of VQ mismatch please see our hypoxia lectures and the mechanisms of hypoxemia now you also get increase in resistance to blood flow especially on the right side specifically and that can cause cardiac arrest in some situations you can actually get the lungs to infarct about 10 percent of the time it's difficult because there's a dual blood supply as many of you know the lungs have a dual blood supply we know that the pulmonary artery goes to the lungs with deoxygenated blood okay so deoxygenated blood goes to the lungs that way but also the aorta which is coming off from the left side of the heart also sends branches over to the lung and so it's difficult to infer the lung completely okay so let's talk about risk factors what are the risk factors for pulmonary embolism now the reason why this is important as we'll talk about later is that there is no test for pulmonary embolism that you would order in another situation and accidentally pick up a pulmonary embolism what do I mean by this I mean the only way you're ever going to make a diagnosis of a pulmonary embolism is if you order a very specific test looking for pulmonary embolism what does that mean that means if you're not thinking about pulmonary embolism you'll never really make the diagnosis so it's very easy to miss it so what are the things that should clue you in that this is a pulmonary embolism well it's risk factors so what are some of the risk factors one it would be an ortho pivec procedure okay so what do I mean by that we're talking hip replacements knee replacements or repair of fractures these sorts of procedures cause patients to not only be laid up in bed but also the endothelial damage that occurs during these surgeries and the fact that these patients probably haven't been moving around very much in the preceding days two weeks before this procedure so if somebody has an orthopedic procedure and comes down with symptoms of tachycardia to give me as we'll talk about then you need to think about a pulmonary embolism number two patients without prophylaxis what do I mean by prophylaxis this is like DVT prophylaxis well the things that we're thinking about in hospitalized patients would be bilateral lower extremity sequential compression devices or anticoagulants things like heparin lovenox warfarin things of that nature even things during surgery so these are all possibilities what's another risk factor number three abdominal or pelvic surgery especially if it's done for cancer so cancer or abdominal pelvic surgery could increase the risk and does increase the risk number four obesity increases the risk number five women greater than thirty years of age and they are on OCPs and they're smokers this is a serious combination right here that you shouldn't forget I've seen personally in the intensive care unit in fact in one month I saw two women over the age of thirty on oral contraceptives who were smokers and they had problems they had pulmonary embolism so bad that in fact they ended up on a ventilator number six hypercoagulable state okay what do I mean by this things for instance like protein C and s deficiencies so you can have one or the other that's a possible risk factor another possibility would be something like factor v leiden that's another type of hypercoagulable state finally the last one would be pregnancy okay so think about these things when we are trying to think whether or not a patient may have a pulmonary embolism because these risk factors certainly could be involved okay what about the symptoms what will be the symptoms or the clinical findings well the first one is a high heart rate known as tachycardia the first thing you'll notice is that that is very nonspecific number two is just as bad and that's two Kip Nia these things here are very nonspecific and can be seen in a number of diseases like pneumonia like a myocardial infarction for instance so you have to be specific and circumspect when you're looking at these because these can fit into many different categories hemoptysis or coughing up a blood especially if there is a lung infection that's impossible clinical finding also signs of pulmonary hypertension so what are those types of signs well you'd sometimes see elevated liver function tests or you would see an increase in the sound of a p2 on auscultation you might also see signs of right ventricular hypertrophy both on palpation and also on the EKG so these are signs and symptoms of pulmonary embolism some of the clinical findings join us for the next lecture when we start to talk about in terms of pulmonary embolism the diagnostic modalities so how do we figure out whether or not this patient really does have a pulmonary embolism it's gonna be an interesting discussion thanks you


  1. Rest In Peace Charlie Whiting

  2. I'm 24. Was given Birth Control to help with menstruation. I questioned it so much up until my leg started going to sleep for no reason. Went back to dr & they stated, " no issues yet". Another dr gave me a lecture on not eating correctly & prescribed pain meds. I came back 2 days later. Still in pain, I just fell down my stairs because my leg gave out. They gave me more pain meds & recommended vitamins < banana >. I woke my husband up the 7th day with my entire right side numb, trouble breathing & losing consciousness. Went to the ER, where they misdiagnosed me again. Said it was pneumonia. Gave me meds but thank God they did a CT of my lungs. Finally found the blood clot. They sent me to an actual hospital & now I'm on eliquis for a year. Awful situation & traumatic! Always question everything.

  3. My husband suddenly passed away aged 59 last month awaiting double hip replacement surgery from a PE caused by DVT. We had been in to see the surgeon 2 months prior and we asked him about the swelling in his legs and he did not warn us of anything or tell us to go to ER. Same thing with his pain dr. We were concerned and no one thought it was an issue. Tell that to our 13 year old daughter.

  4. Thank you for all these videos and all this knowledge Doctor.
    More blood tests were done to try and find where the blood clots are coming from, with tests for Factor V Leiden, and turns out I have heterozygote in my DNA, and have been put on Xarelto for the rest of my life.

  5. Hi please I need urgent advice I have a dvt 20 yeas ago and I'm still havite left iliac all the vein 20cm blooked and have fews blood clot in my lower left leg i will have surgury in 2 weeks time for a stent in my blooked iliac large vein do this surgery increase the risk for PE? Please the cause of my dvt is the behects desease

  6. B

  7. Q: How long can they be in you lungs before Dr's realise they are there? I believe they have been with me for 2 to 3 years, as I started getting strange feelings in my right leg where it would go numb and tingly when walked on, had that checked for DVT and came back clear.
    Then 6 months or so later I get aches/pain behind my left should blade but inside my body area at random, not after eating anything just at random any time, then late last year or very early this year had coughing fits and at night couldn't breath very well and went to the hospital and the young Dr I had blamed smoking and was quit nasty and nothing they could do, and prescribed some pill's, but it settled and seemed normal again but was worried with the pains I was getting and finally asked my Dr what it could be, and was told I have rheumatoid arthritis.
    Thought this must be the situation and I would have to live with it….. Then recently [Three and a half weeks ago] talking to my brother on the phone started to get bad sharp pains in my chest just behind my left breast, I really thought this is it and after about 15 minutes the pain shot straight to the spot behind my shoulder like a knife straight line, wow this was intense, got off the phone and my daughter rang hubby and then I rang the Dr's to see if my Dr was on, yes she was, but when we got there she was busy and we saw another Dr whom called an Ambulance to rush me to the Hospital where they did heaps of blood tests and found nothing, 6 hours later we were sent home pain half strength next day pain gone.
    Nearly 3 weeks later I went to get tablets for quitting smoking and asked about the results from the Hospital, and then about the blood tests, to then hear she was concerned there could be blood clot in a lung as of how high one test came up, so I went to one imaging place in town last Wednesday where they did C/T scan with in to my blood, and when finished headed home thinking all was ok, to them ringing me crazily to go to my Dr for this result Immediately. So this I did to hear yes I do have blood clots to my Lungs, and I asked if he could count them and her said there are many and he wants to save my life. :O
    The other tests were of kidneys and gore bladder, they are stone free but cyst on left kidney, but other wise all organs okay. 🙂
    Now I'm taking Xarelto to thin blood and stop clotting.
    My big question is "How long can blood clots be in your lungs before you know they are there, ?? 1 week, 1 month, or many years if it doesn't kill you first?????
    Kindly Helena

  8. The most frustrating thing is that these don't show alarming symptoms in about half of cases, meaning the first symptom is either sudden death or issues breathing. So half the time you just suddenly die, and in the other quarter your only warning is that you are in the process of dying. I think this is one of those things that will continue to be a problem until there is some advancement that allows us to quickly do a full body assessment as a standard approach to every contact with a doctor.

  9. Thanks so much for this video. I never thought anything about blood clots until I was in a cycling accident on July 12 of this year that resulted in a pelvic fracture (thankfully stable and no surgery) and subsequent DVT in my right calf and clots in my lungs. The first sign for me was the left chest pain, 2 days later right chest pain and shortness of breath. I have been in the ER and hospital the past 2 months way too many times. The lack of information for clots has been frustrating to me. I am also an endurance athlete which I found out is another reason for blood clotting. Thanks again for the education.

  10. Smoking and obesity is crap

  11. What’s wrong with these damn doctors and hospitals cannot pick up something so damn simple wake up morons

  12. Hi my mother diagnosed with PE in CT scan with a contrast. There is a thrombus in the left main pulmonary artery initially given LMWH injections for 5 day’s and then shifted to PRADExa tablets. Will this thrombus go away? how many days will it takes to dissolve thrombus. Currently there’s no signs of DVT.

  13. This took my brother's life 9 months ago. Get checked guys

  14. Very clearly explained!👍

  15. I’m really scared and pregnant 😨

  16. you missed APS as another risk factor

  17. What if there are no blood clots in the knees but only the lungs I’m asking because I have about 10 clots in my lungs but none in my knees the doctor put me on warfarin to help with the clots is it possible to have them form in the chest but not the knees

  18. I just had multiple extensive pulmonary embolisms. I was first misdiagnosed with costochondritis by my pcp. I'm 33, non-smoker, and had just started using Nuvaring for BC. My only symptom was chest pain and it was severe. It hurt to breathe and,to laugh even, and the ER Dr. Promptly did a D. Dimer on me when I went in, followed by all the other tests and being admitted to ICU. I am blessed to be here still.

  19. I'm hoping somehow you read this or someone does cause this is an older video.
    About a month and half ago I started really running out of breath easily and my heart was racing. I was sent to a cardiologist and I found out today all tests turned out fine. He now wants to test and see if I have a blood clot in my lungs cause I'm not really active. Is it even possible to have a blood clot for this long? He said that if nothing shows on this test then I'm just really out of shape. I know I'm not in the best shape but I don't think it's possible to be able to go up 3 flights of stairs with relatively no breathing issues and then the next day almost dying doing the same stairs let alone walking across my 750 sq foot apartment!
    I'm alittle frustrated. I was reading about this lung blood clot and it says nothing about wether you can live with a partial blockage and still be ok? Can someone help please?

  20. Thanks a lot…

  21. Thanks

  22. Good job

  23. Great video. Need to correct spelling. It’s a lot, not alot.

  24. Woahh.. see, im not even in med school, i guess I just like watching surgery's. is that weird?

  25. Leaving this comment up, but I see that you covered CT angio in part 3 of this series. My original comment: You said that you wouldn't find a PE unless you were looking specifically for them. Mine was found through a routine CT angiogram with contrast. I understand now that this is the most common method to find PEs. In my case, my heart was being studied/checked because of family history of CAD. I do not have CAD, but they found a single PE and I am on blood thinner for at least 6 months. The cause of mine is not known yet, but I just had blood tests for the various genetic causes and waiting for results. Will also have a Doppler scan of legs to check for DVTs. I did not have shortness of breath, but I'd been extremely tired for weeks.

  26. My fiancee is getting a sleeve surgery is she at high risk of this??? She is 39yrs old. Im scared

  27. Best medical educator in YouTube … thx doc

  28. Happened to me Jan 5th, i collapsed after only walking up 1 flight of stairs. After 10 days in CCU i'm now on 40mg of Crestor, 5 mg Warfirin, 81 mg aspirin, 5mg ramipril, and 10 mg bisoprolol x2 a day. These will change as time goes on according to dr.

  29. My father just past away yesterday morning because of this. It happened so fast within 30 mins. He was 63. I wish I watched this video before it was too late.

  30. Great truth here! I survived many DVTs but nearly succumbed to a PE which the D Diomer did not verify. Damage to my right side of the heart …. BBBB.

  31. Great video! What about the MTHFR mutation, would that be a risk factor as well? being that someone with this mutation such as myself is more prone to blood clotting. I've been having sharp shooting pains where my heart is or around there anyway sometimes it'll be on the right side too and its worse if I breath in deep but it doesn't last long. I've had this issue for over a year now maybe close to 2 yrs 😞 and I get heart palpitations

  32. i just had a dvt/pe. the doctors sent me home thinking i had sprained my calf. i went back to the hospital the next day and they figured out what was happening. i am now on pradaxa and trying to stay positive. they have no idea why this happened. life is precious. stay strong!!!

  33. I'm 16 and pretty inactive but I'm built nicely and can do exercise easily but I've been having leg pain lately could that be a clot and is it a possibility at my age?

  34. Great stuff

  35. My small clinic doctor missed my PE. I told him I felt exhausted and awful, had sharp throbbing pain on one side of my ribcage. I also told him I thought I might have a clot in my calf, and that I had just flown several hours the day before. I asked him to do an EKG, and it was normal, other than tachycardia. He palpated my leg, said there was no clot, just said it was a muscle strain and sent me home. 36 hours later I called the ambulance. By then the pain had moved to the left side, and my whole ribcage fet tight. Hospital immediately suspected PE, and did CT angiogram. I had 2 large clots in each lung, and several smaller ones. They told me I was very lucky I didn't die.

  36. My mom just passed away from a pulmonary embolism at 58 with absolutely no warning. Happened all within 45 minutes. Other than being over weight, there was no indication that it might even happen.

  37. Great lecture. I just wish this was around back when I was in college!! haha


  39. PE incidence is 600,000 per year worldwide or just in the US?

  40. How about Reduced Resting Heart Rate,with High BP?

  41. she had a son in Jan this year

  42. this killed my sister on Saturday. 🙁 please get checked people. she was 31 and my second best friend.

  43. kindly tell me how much long time we can take the acitrom4 tab for blood thinner…

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