View source for WBR0965

 {{WBRQuestion
|QuestionAuthor= {{M.P}}
|ExamType=USMLE Step 3
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|SubCategory=Hematology
|MainCategory=Primary Care Office
|MainCategory=Primary Care Office
|SubCategory=Hematology
|Prompt=A 50 year old woman comes to the office for routine checkup.  Her past history is otherwise insignificant and her family history is unremarkable.  She is a chronic smoker and smoked two packs of cigarette for the past 25 years.  She attained menopause at the age of 50 and is taking estrogen supplements.  She denies alcohol use and use of recreational drugs.   Her vitals are temperature: 36.7 C, blood pressure: 140/80 mmHg, pulse: 80/min and respirations: 15/min.  All other system examinations are normal.  Her laboratory values comes as :
Hb : 21 g/dl
RBC’s : 6 million/cmm
WBC’s : 6000/cmm
Platelet’s : 300,000/cmm
Neutrophils : 58%
Eosinophils : 2%
Lymphocytes : 33%
Monocytes : 7%

What is the next best step in the management of this patient ?

|Explanation=[[Polycythemia]] is a condition in which there is a net increase in the total number of red blood cells in the body.  Primary polycythemia, often called [[polycythemia vera]] (PCV), [[polycythemia rubra vera]] (PRV), or erythremia, occurs when excess red blood cells are produced as a result of an abnormality of the bone marrow.  Often, excess white blood cells and platelets are also produced.  Secondary polycythemia is caused by either natural or artificial increases in the production of erythropoietin that result in an increased production of erythrocytes.  Physiologic polycythemia, a type of secondary polycythemia occurs in individuals living at high altitudes, where oxygen availability is less than at sea level.  The most common cause of polycythemia is [[hypoxia]] secondary to pulmonary disease; as a result, eliciting symptoms pertaining to altered lung function is of paramount importance.  These include shortness of breath, dyspnea on exertion, chronic cough, history of cyanosis, hypersomnolence with unintentional sleep, as well as details of previously diagnosed heart and lung conditions.



|AnswerA=Obtain liver function tests


|AnswerAExp=''' Incorrect ''' : Abnormal liver function tests may suggest hepatoma, especially if the patient has a previous diagnosis of [[cirrhosis]], [[viral hepatitis]], or [[hemochromatosis]].
|AnswerB=Obtain bone marrow biopsy

|AnswerBExp=''' Incorrect ''' : Bone marrow biopsy is done to rule out polycythemia vera and other hematological malignancies after initial evaluation of ruling out secondary causes.
|AnswerC=Obtain a chest X-ray

|AnswerCExp=''' Incorrect ''' : The chest x-ray may provide additional information (eg, arteriovenous malformations, [[chronic obstructive lung disease]], [[pulmonary hypertension]]) which is done after initial oxygen saturation evaluation.
|AnswerD=Obtain serum erythropoietin levels

|AnswerDExp=''' Incorrect ''' : A low serum Epo level in the patient with erythrocytosis is relatively specific for the diagnosis of polycythemia vera (PV) and erythrocytosis associated with increased serum Epo is unlikely to represent PV and a working diagnosis of secondary erythrocytosis should be made.
|AnswerE=Obtain oxygen saturation
|AnswerEExp=''' Correct ''' : The most common cause of polycythemia is hypoxia secondary to pulmonary disease and pulse oximetry for estimation of arterial oxygen saturation is considered a vital sign.  Since some patients will not show reduced values for oxygen saturation while at rest or during the daytime, [[pulse oximetry]] should be obtained after minimal exertion. 
|RightAnswer=E
|WBRKeyword=Polycythemia, 
|Approved=Yes
}}