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|MainCategory=Physiology
|MainCategory=Physiology
|SubCategory=Cardiology
|SubCategory=Cardiology
|Prompt=A 38 year old woman is undergoing work-up for idiopathic pulmonary hypertension. During pulmonary artery catheterization her cardiologist makes the following measurements:
|Prompt=A 38 year old woman is undergoing work-up for idiopathic pulmonary hypertension. During pulmonary artery catheterization her cardiologist takes the measurements shown below. What is this patient's estimated cardiac output? <br>
Pulmonary capillary wedge pressure = 9 mmHg<br>
 
Right atrial pressure = 3 mmHg<br>
Pulmonary capillary wedge pressure = 9 mmHg
Pulmonary artery pressure  = 23 mmHg<br>
 
AV CO<sub>2</sub> difference = 28 ml/m<sup>2</sup><br>
Right atrial pressure = 3 mmHg
AV O<sub>2</sub> difference = 36 ml/m<sup>2</sup><br>
 
Rate of O<sub>2</sub> consumption = 190 ml/min/m<sup>2</sup><br>
Pulmonary artery pressure  = 23 mmHg
 
AV CO<sub>2</sub> difference = 28 ml/m<sup>2</sup>
 
AV O<sub>2</sub> difference = 36 ml/m<sup>2</sup>
 
Rate of O<sub>2</sub> consumption = 190 ml/min/m<sup>2</sup>


What is this patient's estimated cardiac output?
|Explanation=Fick's principle is a simple way to calculate cardiac output by using the arteriovenous oxygen difference and rate of oxygen consumption that can be measured during right heart catheterization (pulmonary artery cathterization). The equation used is shown below:
|Explanation=Fick's principle is a simple way to calculate cardiac output by using the arteriovenous oxygen difference and rate of oxygen consumption that can be measured during right heart catheterization (pulmonary artery cathterization). The equation used is shown below:



Revision as of 03:32, 11 November 2013

 
Author [[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Physiology
Sub Category SubCategory::Cardiology
Prompt [[Prompt::A 38 year old woman is undergoing work-up for idiopathic pulmonary hypertension. During pulmonary artery catheterization her cardiologist takes the measurements shown below. What is this patient's estimated cardiac output?

Pulmonary capillary wedge pressure = 9 mmHg

Right atrial pressure = 3 mmHg

Pulmonary artery pressure = 23 mmHg

AV CO2 difference = 28 ml/m2

AV O2 difference = 36 ml/m2

Rate of O2 consumption = 190 ml/min/m2]]

Answer A AnswerA::8.26
Answer A Explanation AnswerAExp::Incorrect
Answer B AnswerB::7.66
Answer B Explanation AnswerBExp::Incorrect
Answer C AnswerC::7.03
Answer C Explanation AnswerCExp::Incorrect
Answer D AnswerD::6.78
Answer D Explanation AnswerDExp::Incorrect
Answer E AnswerE::5.28
Answer E Explanation AnswerEExp::Correct
Right Answer RightAnswer::E
Explanation [[Explanation::Fick's principle is a simple way to calculate cardiac output by using the arteriovenous oxygen difference and rate of oxygen consumption that can be measured during right heart catheterization (pulmonary artery cathterization). The equation used is shown below:


Learning objective:


Reference:
Grossman J, Weston RE, Leiter L. A method for determining cardiac output by the direct fick principle without gas analysis. J Clin Invest. 1953;32(2):161-71.
Educational Objective:
References: ]]

Approved Approved::No
Keyword WBRKeyword::Fick's principle, WBRKeyword::Cardiac output, WBRKeyword::oxygen consumption, WBRKeyword::right heart catheterization, WBRKeyword::pulmonary artery cathterization
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Order in Linked Questions LinkedOrder::