no evidence for human-to-human transmission, disease in humans occurs
when spores are inhaled. Working with untreated animal hides increases
the risk for anthrax exposure.
ThoughS pneumoniaeandH influenzae(a and d)can cause respiratory
failure, it is unlikely to occur in a healthy 32-year-old man. (b)Diphtheria
is a potentially life-threatening disease that is characterized by a gray-green
pseudomembrane covering the tonsils and pharyngeal mucosa. Coxiella
burnetii(c)is the organism that causes Q fever. It is similar to B anthracisin
that sheep, cattle, and goats are the primary reservoirs. However, deterio-
ration because of Q fever is not as rapid as that seen in anthrax.
71.The answer is b.(Rosen, pp 1005-1009.)Given this patient’s longstand-
ing history of tobaccouse and having not seen a doctor for annual examina-
tions, it is likely that the pleural effusion is exudativeas a result of an underlying
malignancy. Other causes of exudative effusions include the following: infec-
tion, connective tissue diseases, neoplasm, pulmonary emboli, uremia, pancre-
atitis, esophageal rupture, postsurgical, trauma, and drug-induced. Pleural fluid
analysis includes LDH, glucose, protein, amylase, cell count, Gram stain, cul-
ture, and cytology.
(d and e)Effusions that have a LDH > 200 U, fluid-to-blood LDH ratio
0.6 and a fluid-to-blood protein ratio > 0.5 are classified as exudative. Levels
less than these are classified as transudative. (a)Causes of transudative effu-
sions include CHF, hypoalbuminemia, cirrhosis, myxedema, nephrotic syn-
drome, superior vena cava syndrome, and peritoneal dialysis. (c)An effusion
cannot be both exudative and transudative.
72.The answer is a.(Rosen, pp 1147-1148.)In a patient with untreated
HIVand bilateral infiltrateson chest x-ray, PCPmust be considered, in addi-
tion to community-acquired pneumonia. Corticosteroids are shown to be
beneficial as adjunctive therapy in patients with moderate to severe PCP. They
(1) limit oxygen deterioration, (2) decrease mortality and respiratory failure,
and (3) accelerate recovery. Therapy should be initiated to all children and
adult patients with a PO 2 < 70 mm Hg or an A-a gradient > 35 mm Hg. It is
important to initiate steroid therapy prior to starting antibiotics to avoid wors-
ening hypoxia that is secondary to the inflammatory reaction caused by dying
organisms.
(b)Immediate treatment with IV TMP/SMX would be correct if the
PaO 2 were greater than 70. (c)Delay of antibiotics is never appropriate in an
ill patient with suspected pneumonia. Gram stain is unlikely to be useful in
Shortness of Breath Answers 75