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40. A 54-year-old man has a 3-week history of bilateral ankle swelling. Evaluation shows the following pressures:
Capillary hydrostatic 32 mm Hg N=35-45
Interstitial hydrostatic 10 mm Hg N=2-5
Capillary oncotic 18 mm Hg N=23-27
Interstitial oncotic 0 mm Hg N=1-3
Which of the following is the most likely explanation for the ankle swelling?
A. Chronic bronchitis
B. Congestive heart failure
C. Hepatic venous outflow obstruction
D. Lymphatic obstruction
E. Nephrotic syndrome
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Yes, E. Since the capillary hydrostatic pressure is a little low, then we can cross off answers B, and D, since those would increase the capillary hydrostatic pressure. He could also be hypovolemic, but they don't ask that....
Since the capillary oncotic pressure is also low, then he must have less protein than normal in his capillaries. Nephrotic is the best choice.
I don't know why they put A in there as a distractor.
For fun, let's figure out the net filtration pressure: The way I do this is just to add up each contributing number, with a + sign if it's outward flow and - if it's inward (into the capillary) flow.
+32 - 10 - 18 - 0 = +4
Since the sign is positive, then the net flow is outward. We don't need to do this to answer the question, but it's probably good to be able to do this quickly.
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Dear goober
Correct me if I'm wrong
Hepatic venous obstruction..increase capillary HP
Lymmphatic obstruction...increase interstitial OP...
so as u said ,since capillary HP is a little low..we can exclude B and C.not B and D..am i right?
Interstitial OP is zero so we can exclude choice D...
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Yes, shwe, you are right. I made a mistake. Since capillary HP is low, we can exclude B and C.
The answer is still E because lymphatic obstruction would not explain the reduced capillary oncotic pressure, and it would be very unlikely to be bilateral.
