UWorld question

[pbnj003]

Ref: QID- 2099

im not sure if i can write out the whole question here but if someone is currently doing uworld and has come accross this question I would appreciate some feedback.

This question has to do with Korotkoff sound. Patient was brought to ER blah blah BP measure and first korotkoff sound heard at 100 during expiration then at 78 korotkoff sounds are heard throughout the respiratory cycle. The question was which of the following is responsible for the physical findings. ( Aortic dissection, Peripheral vascular disease, Aortic or Mitral valve problems, Pericardial disease) Answer was pericardial which causes the pulsus paradoxus.

now in the explanation its all about Pulus paradoxus, which i understand.

However I am having a hard time understanding the question. The reason I couldnt answer the question was becuase I didnt understand it. I guess maybe I dont understand Korotkoff sound or something? I just dont get how you can derive pulsus from this?

anyone can explain this? would much appreciate it.

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[MrBeauregard]

Pulsus paradoxus can be a difficult concept to understand. This is probably one of the better explanations that I could find in a short time since I don't have the time to type out an explanation right now. Scroll down until you find the 'Physiology' section, as that is the explanation.

If this still doesn't make sense, I am sure there are people on here who can adequately explain pulsus paradoxus in a way that makes sense. Hope this helps!

 

[jfgavina]

Pulsus paradoxus is a decrease in blood pressure of more than 10 mmHg during inspiration. well if you remember during inspiration you increase your venous return, so the amount of blood reaching your right heart is increased. What happens when your systolic blood pressure decreases? it means that the heart is not pumping blood as it should be, so pulsus paradoxus is this! you increase your amount reaching right heart and you overwhelm your right heart so he cannot distend according to frank-starling to accomodate more blood and pump it! why it cannot distend ? because something outside it must be compressing the chamber and not letting blood enter. when you have pericardal effusion you have liquid compressing your right heart from outside to inside, therefore you get pulsus paradoxus.

 

[pbnj003]

ok so I get the concept of pulsus paradoxus, as in why and how you get the decrease of more than 10.

Ok heres the question.

"A 37 y.o. patient is being assessed in the ER for shortness of breath and lightheadedness. The BP cuff is inflated to 130 mmHG and the pressure is slowly released. At 100 mmHG intermittent Korotkoff sounds are heard only during expiration. At 78 mmHG Korotkoff sounds are heard throughout the respiratory cycle. Which of the Following is the most likely explanation to the physical finding"

A. Aortic Dissection
B. Peripheral Vascular Disease
C. Aortic Valve disease
D. Mitral Valve disease
E. Pericardial disease.

See the problem for me with this problem was, I didnt and still dont understand the question. I could pick any of the answer choices.

So i was hoping someone would help me understand the question. THe explanations about pulsus paradoxus did help clarify the concept of paradoxus but still when i read back on the question I still dont get the question.

 

[jfgavina]

I understand you because I missed that question as well LOL

this examination (or let's hope only the most difficult questions) besides testing the concepts which they expect you to know they test you as a person. to be more specific, they want you to be on amphetamines during the examination and with maximal attention otherwise you won't go far!

they say 100 mmHg heard only during expiration and 78mmHg heard through the respiratory cycle. they want you to find that this is pulsus paradoxus because the blood pressure decreases in the rest of respiratory cycle (inspiration)! that's why you get 100 mmHg in expiration and a big decrease to 78 mmHg in the inspiratory phase

 

[notarealname]

ok so I get the concept of pulsus paradoxus, as in why and how you get the decrease of more than 10.

Ok heres the question.

"A 37 y.o. patient is being assessed in the ER for shortness of breath and lightheadedness. The BP cuff is inflated to 130 mmHG and the pressure is slowly released. At 100 mmHG intermittent Korotkoff sounds are heard only during expiration. At 78 mmHG Korotkoff sounds are heard throughout the respiratory cycle. Which of the Following is the most likely explanation to the physical finding"

A. Aortic Dissection
B. Peripheral Vascular Disease
C. Aortic Valve disease
D. Mitral Valve disease
E. Pericardial disease.

See the problem for me with this problem was, I didnt and still dont understand the question. I could pick any of the answer choices.

So i was hoping someone would help me understand the question. THe explanations about pulsus paradoxus did help clarify the concept of paradoxus but still when i read back on the question I still dont get the question.

hmm... which part of the question you don't understand? At higher pressure 100 mmHg, you only hear during expiration because expiration has higher blood pressure due to pulsus paradoxus. In other words, at 100 mmHg when you inspire you get the effect of the pulsus paradoxus, your right heart is restricted due to the pericardial effusion, so your right heart can not fill all the blooded needed to have the same stroke volume, therefore less blood move to your lungs, less to your left heart means less stroke volume of left heart means decrease of blood pressure, with decreased blood pressure, your blood pressure doesn't overcome the pressure created by the pressure cuff that cut off your circulation on your arm because your blood pressure if lower than cuff pressure at 100mmHg when you inspire, therefore you don't hear anything when you inspire.... that's why the answer is pericardial disease...

Let me know if this make sense...

 

[notarealname]

I understand you because I missed that question as well LOL

this examination (or let's hope only the most difficult questions) besides testing the concepts which they expect you to know they test you as a person. to be more specific, they want you to be on amphetamines during the examination and with maximal attention otherwise you won't go far!

they say 100 mmHg heard only during expiration and 78mmHg heard through the respiratory cycle. they want you to find that this is pulsus paradoxus because the blood pressure decreases in the rest of respiratory cycle (inspiration)! that's why you get 100 mmHg in expiration and a big decrease to 78 mmHg in the inspiratory phase

Good job on getting into the mind of the exam writers 😛