Author Question: A patient with a small number of spherocytes, increased reticulocytes, and increased MCHC has a ... (Read 38 times)

lidoalex · **on:** Jun 25, 2018

A patient with a small number of spherocytes, increased reticulocytes, and increased MCHC has a normal osmotic fragility. Select the best course of action.

a. Dismiss the spherocytes as an artifact.
b. Repeat the osmotic fragility after incubating the blood at 37 C for 24 hours.
c. Check the cell counter for errors in the MCHC.
d. Collect a new blood sample.

Question 2

A patient with a previously compensated hereditary spherocytosis has a severe drop in hemoglobin after a parvovirus infection. This represents what type of crisis?

a. Megaloblastic
b. Hemolytic
c. Aplastic
d. Anemic

bbburns21 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: B
Incubating the blood at 37 C for 24 hours can increase the sensitivity of the osmotic fragility so that a previously normal result becomes abnormal. During this incubation period, red cells become metabolically deprived and tend to lose membrane surface because of their relative membrane instability.

Answer to Question 2

ANS: C
After some viral infections, particularly with parvovirus B19 that invades developing red cells and inhibits their growth, a severe drop in hemoglobin can occur. This is termed an aplastic crisis.