WBR0883

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
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: Educational Objective: References: 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.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Fick's principle, WBRKeyword::Cardiac output, WBRKeyword::oxygen consumption, WBRKeyword::right heart catheterization, WBRKeyword::pulmonary artery cathterization
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::