Pulmonary Embolism (PE)

hey guys it's medicos is perfection a

loss for medicine just seems to make

perfect sense we continue our discussion

in both pulmonology topics today we'll

talk about pulmonary embolism by the way

in the previous video we discussed DVT

or deep venous thrombosis

now it's PE a medical emergency here's

the story you start with DVT deep venous

thrombosis your leg is gonna be hot warm

tender with positive Homans sign this

was DBT then the clot will dislodge

probably at the femoral vein level and

then it becomes an embolus goes to your

pulmonary artery to block it and this is

pulmonary embolism the patient is


he may have shorts of breath and he

might even have him up toises or

coughing of blood he's also gonna have

tech accordion cough and/or dyspnea is

lung disease and you have one of five

options today we're talking about

pulmonary vascular abnormalities and

here it is clinically there are three

types of Fleury embolism there is low

risk PE there is sub massive PE and

there is massive P which is rapidly

fatal and the patient is hemodynamically

unstable one example of massive embolus

is the saddle embolus it's like the sale

of the donkey and you're sitting like

this right and you're smiling same thing

with the ambos the embolus is saddling

the pulmonary trunk and both pulmonary

arteries and this can kill you in a

second what's the difference between low

risks of massive and massive PE low risk

has normal blood pressure and normal

serum biomarkers sub massive has normal

blood pressure but biomarkers will show

RV dysfunction myocardial necrosis high

tripping and I B and P massive will have

hypotension RV's function Michalek rosa

high troponin high brain natriuretic

peptide absent poles called

pulselessness and severe bradycardia

this is hemodynamic instability

nephrotic syndrome can lead to pulmonary

embolism why because in nephrotic

syndrome you are losing proteins

including antithrombin 3 protein c and

protein s those are ant

i coagulation in a sense when you lose

anticoagulants you are becoming Pro

coagulation so you'll form thrombosis

what is the most common location of

thrombosis it's actually the renal vein

Ward because in the kidney which has

nephrotic syndrome antithrombin 3

protein CM protein s has just passed

down the toilet what is the next step

after you lose these proteins the next

step is the renal vein until you go back

to the heart that's why renal vein

thrombosis is the most common just by

the location or the logistics of the

place which condition can happen only in

case of left renal vein but not at the

right because as you know the left

testicular vein drains into the left

renal vein but the right testicular vein

drains directly into the inferior vena

cava so if you have a left renal vein

thrombosis like this one blood cannot

actually drain to the inferior vena cava

it's gonna pull down here and accumulate

and you will end up with left-sided

varicocele which is a bag of warm kind

of a sensation and this can lead to male

infertility why not the right side

because the right side drains directly

into the IVC so even if you have a right

renal vein thrombosis it's not gonna

matter what is the most accurate test to

diagnose DVT it's actually contrast

venography it's very invasive and it's

rarely done but what's the gold standard

that we actually use it

it's called compression ultrasound or

compression Doppler sometimes there is

something called duplex and duplex as

you might imagine has two things number

one it has ultrasound to review the

structure and also has an ultrasound for

the flow so structure and floats called

duplex and yes you can use it to

diagnose DVT when should you rely on the


only if the patient has low pretest

probability because only then will the

d-dimer have a high sensitivity and

therefore a high negative predictive


and a high ability to exclude DVT and

I've talked about this before in the

previous video what's the definition of

PE sudden blockage of a pulmonary artery

or one of its branches by an embolus

it's a dislodged thrombus what is the

most common site of thrombosis deep

veins of the light what is the most

common site of embolization femoral vein

where is it coming from from DVT what

exactly some of you think that DVT only

happens in the calf not true it could

happen in the Lord half of the body or

in the upper half of the body lower half

such as deep veins of the cap yes this

is the most common but not the only one

it could be in the popliteal vein from a

vein pelvic vein and even renal veins or

upper half of the body especially

because today we use a lot of IV

catheters and pee I see sea lions you

can find them in the upper extremity

veins internal jugular veins and

subclavian vein DVT which is a thrombus

and the deep veins of the lower leg will

go to the femoral vein and then start to

dislodge embolus plug the pulmonary

artery leading to ventilation without


this increases the VQ ratio to the point

of infinity going to VQ mismatch this is

called dead space physiology not to be

confused with shunt physiology this will

lead to less oxygen going to the

pulmonary artery hypoxemia hypoxia

billing - reflex vasoconstriction in the

pulmonary blood vessels this

vasoconstriction will lead to loss a

function of the type to nuuma site loss

of surfactant and eight Alexis's and

this is the most common finding on chest

x-ray in a patient with pulmonary

embolism less blood supply to the lung

ischemia and in fortune in the lung and

in the lung it's triangular because of

the branches of the arteries


and it's red in fortune because the lung

has multiple blood supplies such as

pulmonary artery bronchial arteries and

pulmonary veins through back diffusion

decreased radius will lead to increased

vascular resistance increased pressure

in the pulmonary artery is a secondary

pulmonary artery hypertension increase

work on their right ventricle of the

heart but your right

or pulmonary circulation has a great

capacitance this will lead to nothing

even if you include the your pulmonary

artery up to 50% of the vessels but if

you include more than 50% of the vessels

or you include the trunk of the

pulmonary trunk bad news this can kill

you and this saddle embolus can be fatal

in a second clinically the symptoms

include sudden onset of shortness of

breath also has Disney pleuritic chest

pain hemoptysis and productive cough

productive of what blood-tinged sputum

so it could be just blood team sputum or

it could be frank hemoptysis signs

includes sudden onset of tachypnea

tachycardia respiratory distress

what is pleuritic chest pain Florida

chest pain is when you feel pain when

you breathe in like this it hurts but

then if you hold your breath it's not

hurting question can we use chest x-ray

to diagnose pulmonary embolism you are

so naive you are more naive than the

b-lymphocytes before they recognize the

antigen now we cannot use just extreme

diagnosis the best that you can hope for

is to rule out other diagnoses what's

the most common finding on chest x-ray

okay you're still insisting on using

this stupid thing eight electus

some of your books that your guys are

reading they say the most common finding

on chest x-ray is normal and not true

what other findings other than intellect

assist could be seen on chest x-ray

Hamptons hump which is a wedge shaped in

part again the triangular in fourth

Wister mark sign which is a leukemia

because there is no blood it's called a

perfusion defect guys plus blood is

going to the lung lack of vascular

markings on chest x-ray those markings

that you see on chest x-ray

you will see fewer of them because there

is no blood palace sign enlargement of

the right descending pulmonary artery

pulmonary consolidation due to eight

electives and when we say consolidation

it means it has involved the alveoli

elevated hemidiaphragm due to eight

electors of course let's say it happened

in your in this long which is the right

lung and now the right lung is

like this the diaphragm instead of being

here it's gonna go up to compensate

because nature hates either question

number two can we use aspirin hay to

treat pulmonary embolism that's another

naive presumption no anti platelets at

best may prevent a clot from happening

and even then the number needed to treat

is ridiculously low but in PE you

already have a freakin clot in the

polynomial prevent what you already have

the stinking thing so for DVT or PE

aspirin is total BS to miss that you

should not believe myth number one chest

x-ray can diagnose PE

it cannot number two aspirin should be

used to treat no it should not okay how

to diagnose DVT or PE we have welds

criteria for DVT which are different

from Welles criteria for PE we have

talked about Welles criteria for DVT in

my last video here are the world's

criteria for DVT again watch my previous

video please

now Welles criteria for PE here is the

criterion and here is the score and the

interpretation if you have clinical

signs of DVT give the patient three

points any alternative diagnosis is less

plausible than PE give the patient

another three points because now PE is

the most likely diagnosis if there is

take a card he would buy tachycardia I

mean heart beat greater than 100 beats

per minute give one point and a half

history of recent major surgery or

immobilization in the last four weeks

again one and a half points previous

medical history of DVT or PE one and a

half points hemoptysis one active cancer

or at least in the past six month

another point then the interpretation if

the total is zero to one this is low

probability of Lemuria mole isn't to the

six moderate more than six is high

probability here is my mnemonic for

Wells criteria for DVT which was

discussed in the previous video Wells

criteria for PE on the other hand are

here clinical signs and symptoms 3p is

the number one diagnosis three to Cordia

one and a half emulation one and a half

history of DVT a one and a half I'm up

to this one malignancy one here is my

visual mnemonic to remember

wels criteria for PE everything here is

a joke but it works because I want you

to remember this on your exam and in

real-life situations so that you can

save people's lives here you have a room

in a hospital with four people a patient

is grandma a competent nurse and a crazy

doctor question which one makes the most

money and the answer is the doctor so

everything the doctor says gets you the

highest score which is three points each

who is the second highest income earner

the competent nurse so everything the

nurse utters will give you a score of

one and a half points who is the Baroque

hist one sweet grandma she's retired and

her salary depends on the government

pension plan who is run by people who

cannot even add let alone subtract so

everything grandma mentions yields 1.0

then you add the points together to form

a Wells score for pulmonary embolism if

the result is 0 to 1 low probability if

the total is 2 to 6 moderate probability

if the net is more than 6 high

probability for pulmonary embolism and

this is a freaking medical emergency so

you should get your head out of your

helmet and act fast let's start with the

doctor everything is three points first

the doctor found the clinical signs and

symptoms of PE only a doctor can say

that not granny so this is three points

second pulmonary embolism is the most

likely diagnosis in this patient at this

moment so we have DVT we have to keep

here we have this meal we have him Optus

we have Florida chest pain maybe cough

okay add another three points now let's

talk about the competent nurse because

the doctor is not always there he is

busy driving his Ferrari because he

earned so much money the nurse can and

should measure the vital signs therefore

tachycardia one and a half she has been

with the patient since he has got into

the hospital he has been bedridden for

three days one and a half for

immobilization and the nurse has access

to the medical records so if he has a

history of DVT or PE another one and a

half points last sweet grin

says while this nurse was busy talking

to her boyfriend on facebook messenger

my grandson cuffed up blood hemoptysis

one point and now I want to talk to her

supervisor don't pay attention to granny

now and just add one point to your notes

because you can get the supervisor and

the four of you will keep yelling at

each other while the patient dies from

an embolus because he was high

probability but the doctor didn't count

and was busy talking to granny patients

come first so here is what you should do

- grandma you say this okay madam before

I get you the supervisor does your son

have any history of any cancer yes you

add one point at this point grandma will

be mad at you because you're not looking

at her and not paying attention and now

she demands to talk to your supervisor

so you should tell her while starting

heparin and oxygen I will get you my

supervisor and the head of the hospital

and we'll give you the number of the

American Medical Association - the hell

with it I'm gonna save your grandson's

life before the saddle embolus trials as

pulmonary trunk at the bifurcation with

while giving the two main pulmonary

arteries and that's how you remember the

world's criteria for pulmonary embolism

score is more than six high probability

to the six-month probability less than

two low probability after diagnosed PE

step number one clinical Wells criteria

and wells criteria step two go to the

lab if wells criteria for DVT use low

probability for DVT order d-dimer

intermediate - hi Parvati compression

ultrasound of the light high probability

of DVT plus ultrasound actually showing

a freakin clot above the knee trait for

PE but I have not confirmed PE yet it's

going up to the PE it's gonna reach the

pulmonary artery soon act quickly doofus

intermediate to high probability plus

ultrasound that did not show a clot say

T pulmonary angiogram or C TPA which is

non-invasive but if the patient is

morbidly obese or allergic to the

contrast or iodine or has

fear cannot give contrast to people with

renal failure

then you do VQ scan which is

non-invasive and does not use the

freaking contrast if CT pulmonary

angiogram and or the VQ scan are not

clear and are not diagnostic you do

pulmonary angiography and this is

freakin invasive so CT pulmonary

angiogram is non-invasive it's just city

scan with contrast that looks at the

pulmonary artery and its branches but

pulmonary angiography is in vase if you

actually poked the patient with this

sting goes this probe this probe is

going up until it reaches the pulmonary

trunk and the pulmonary arteries and

their branches and then you take x-ray

pictures called fluoroscopy to see the

actual clot and this is super invasive

so this is last resort and nowadays we

do not use pulmonary angiography that

often because CT pulmonary angiography

is better faster and less invasive so

here are the lab investigation or the

radiological investigations to diagnose

PE ABG with pulse oximetry it's

nonspecific the a gray is gonna be

widened pao2 is loads called hypoxemic

about chest x-ray again this cannot

diagnose PE it can exclude but cannot

include PE what should you see you can

see it electus which is the most common

finding consolidation Hamptons hunt West

amok sign or Palace sign ECG you can

suggest PE but cannot diagnose it you

will see sinus tachycardia which is the

most common finding on ECG s-one q-three

t3 and this is a sign of right

ventricular stress strain what the flip

is s-one q-three t3 it means

s wave is large in lead 1 the Q wave is

large in lead 3 and the t wave is

inverted in lead 3 CT pulmonary

angiogram which uses a helical CT

formerly known as spiral CT is standard

non-invasive modality contains iodine

contracts to avoid in case of iodine

allergy or renal failure VQ scan

it's the modality of choice if you have

a patient who is allergic to the iodine

has renal failure or morbidly obese and

this is of choice for recurrent

pulmonary embolisms because CT scan

again and again again is not the best

thing to do

compression ultrasound if the patient

has welds criteria for DVT and the

ultrasound is again very specific

d-dimer is only used for low pretest

probability it can roll out but it

cannot rule in pulmonary angiography is

called standard it's very invasive it

uses for rasca which contains x-ray and

only use it if the CT Pommery

angiography is equivocal and if the VQ

scan is not diagnostic echo is a piece

of garbage it might show RV strainer or

V dysfunction MRI or magnetic resonance

angiography troponin troponin

troponin t may be elevated in sub

massive or massive pulmonary embolism

such as the famous saddle embolus how to

diagnose PE step 1 clinical the world's

criteria step 2 lab tests again please

memorize this my favorite part of the

lecture Turco's try it increases your

risk of venous or arterial thrombosis

polycythemia vera which is a frickin

myeloproliferative neoplasm as well as

paroxysmal nocturnal hemoglobinuria

which is a flippin hemolytic anemia both

can increase your risk of thrombosis

it could be DVT or PE PE is the most

common preventable cause of death in

hospitalized patients that's why I'm

always yelling at you because I want you

to be a good doctor not a doofus with a

stethoscope PE is the third most common

cardiovascular cause of death number one

is ischemic heart disease alternate

heart attack or myocardial infarction

number two is stroke the most common

site of thrombus formation in case of

DVT is deep veins of the leg most common

site of embolization not from BOCES but

embolization is the femoral vein most

cases of PE came from a DVT which

happened above the name most calf vein

thrombosis do

not embolize about one out of every ten

patient with PE die within the first

hour again don't be a doofus and act

quickly and save the patient's life and

don't care about granny right now sorry


the world's criteria determined the

pretest probability so if the wealth

criteria show high probability we call

this a high pretest probability

translation let's say we're talking

about wealth criteria for DVT if we have

a score that's high which means high

probability of DVT d-dimer becomes

useless if Wells criteria for PE showed

a low probability and the VQ scan yield

low probability you have successfully

ruled out pulmonary embolism if a

patient is at risk of bleeding and you

have to give heparin give heparin as IV

infusion or IV drip like drip drip drip

not in one single shot and by giving a

drip you can stop it

any time thank you for watching please

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stay happy and study hard this is minik

oh she's perfection elsewhere medicine

makes perfect sense