WBR0676

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Biochemistry, MainCategory::Pathophysiology
Sub Category	SubCategory::Cardiology, SubCategory::Oncology
Prompt	[[Prompt::A 62-year-old man, with a past medical history of myocardial infarction and heart failure, is brought to the emergency department in severe shortness of breath. He is barely able to continue his sentences and is breathing heavily even at rest. Physical examination is remarkable for tachycardia, tachypnea, diffuse fine crackles on pulmonary auscultation, and lower extremity edema. Following appropriate work-up and imaging, the diagnosis of cardiogenic pulmonary edema is made. If the patient's pulmonary fluid and serum are to be analyzed, which of the following will most likely be present?]]
Answer A	AnswerA::High fluid to serum protein ratio
Answer A Explanation	AnswerAExp::Transudative fluid usually has a low fluid to serum protein ratio.
Answer B	[[AnswerB::Fluid specific gravity > 1.015]]
Answer B Explanation	[[AnswerBExp::The specific gravity in transudative fluid is usually low < 1.015.]]
Answer C	AnswerC::High fluid to serum lactate dehydrogenase (LDH) ratio
Answer C Explanation	AnswerCExp::Transudates generally have a low fluid to serum lactate dehydrogenase (LDH) ratio.
Answer D	AnswerD::Fluid poor in cellular components
Answer D Explanation	AnswerDExp::Transudates have fluid poor in cellular components.
Answer E	AnswerE::Serum with elevated oncotic pressure
Answer E Explanation	AnswerEExp::Cardiogenic edema has low serum oncotic pressure.
Right Answer	RightAnswer::D
Explanation	[[Explanation::Cardiogenic pulmonary edema is one of the main manifestations of fluid transudation due to increased hydrostatic pressure. Transudates can be distinguished from exudates by their hypo cellular and protein-poor fluid. Accordingly, they have low specific gravities, usually < 1.015. Cardiogenic edema is due to elevated hydrostatic pressures and low oncotic pressures. In contrast, exudates are cellular, protein-rich fluids that have high specific gravities, usually > 1.015. They are commonly caused by lymphatic obstruction and inflammation. Transudation may occur into the parenchyma leading to pulmonary edema or the pleura leading to pleural effusion. Educational Objective: Cardiogenic edema is associated with transudative fluid and low oncotic pressure and high hydrostatic pressure. References: Kumar V, Abbas AK, Aster JC. Robbins Basic Pathology. Chapter 2: Inflammation. Elsevier Health Sciences; 2012.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Oncotic pressure, WBRKeyword::Hydrostatic pressure, WBRKeyword::Cardiogenic pulmonary edema, WBRKeyword::Pulmonary edema, WBRKeyword::Exudative, WBRKeyword::Transudative
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::