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The D question - amir2000 - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 2 CK (https://www.usmleforum.com/forumdisplay.php?fid=3) +--- Thread: The D question - amir2000 (/showthread.php?tid=211418) |
The D question - amir2000 - ArchivalUser - 08-19-2007 A 67-year-old man comes to the physician because of a 2-month history of progressive shortness of breath. He has had a 4.5-kg (10-lb) weight loss over the past 4 months. He has not had chest pain. He has congestive heart failure treated with furosemide, digoxin, and enalapril. He has smoked two packs of cigarettes daily for 30 years. He appears alert and is in no acute distress. His temperature is 37.2 C (99 F), blood pressure is 140/85 mm Hg, pulse is 84/min, and respirations are 18/min. Examination shows no jugular venous distention. There is dullness to percussion, and breath sounds are decreased at the left base. Cardiac examination shows a laterally displaced point of maximal impulse, normal S1 and S2, and an S3 at the apex. There is 1+ edema over the extremities. An x-ray film of the chest shows an enlarged cardiac silhouette, left hilar fullness, and a moderate-sized left pleural effusion. Thoracentesis yields straw-colored fluid. Laboratory studies show: Serum Glucose 90 mg/dL Protein 7 g/dL Lactate dehydrogenase 300 U/L Pleural fluid pH 7.25 Glucose 75 mg/dL Protein 4.5 g/dL Lactate dehydrogenase 280 U/L Leukocyte count 2000/mm3 Segmented neutrophils 15% Lymphocytes 85% A Gram's stain and acid-fast stains are negative for any organisms. Which of the following is the most likely cause of this patient's pleural effusion? A ) Bacterial pneumonia B ) Collagen vascular disease C ) Congestive heart failure D ) Malignancy E ) Pulmonary embolus with infarction F ) Viral pleuritis all the prevous answers were D,but i think it is A for the following reasons 1-in malignancy the fluid should be turbid to bloody ,the predominant cells is monocytes 2-straw coloured effusion is seen only in two conditions TB and pulmonary embolism and off course all we agree this case isnot pulmonary embolism 3-so we have only TB to think about and all the values of the fluid go with TB(cell count 1000-5000 with lymphocytes predimonant) now you are going to ask me 2 questions 1-the acid fast stain is negative?!!!and acutally it is, but this triggers a major issue in infectios disease, what is the golden test to detect infection and the answer is tissue biopsy ,so it willnot be wondering if you have TB and your acid fast stain of sputum or the plural fluid is negative because these are not the best diagnostic test for TB and you can have false negative test many times 2-the other thing you might ask,is TB is bacterial pnumonia so that we can pick option A,?!!!!! and i think it is a bacterial pnumonia ,what is pnumonia,it is inflmation of lung paranchyma and TB is granulamatous inflamation of the lung paranchyma, and what about the word bacteria,actully as i know TB is a bacteria unless it latly has been classified as virus or fungi!!!!! SO as a summary i think the answer is A and nbme guys just playing with the words and terms to make it more confusing. Thx for reading my post and please correct me. 0 - ArchivalUser - 08-20-2007 I think the pleural fluid analysis is clearly an exudate! so why to even consider other options. Can you please tell me in what other cases(listed above) the pleural fluid analysis will show the similar picture. |