Which of the following could account for the red cell indices on ...

[waynest]

Which of the following could account for the red cell indices on Mary Jones reviewing Questions 13
 
  a. Determining a likely cause is not possible.
  b. An error in the hemoglobin probably has been made.
  c. An error in the red cell count probably has been made.
  d. An error in the microhematocrit probably has been made.

Question 2

Interpret the following results (all tests performed manually) on an adult female named Mary Jones.
 
  RBC: 3.22 x 1012/L
  Hemoglobin: 16.0 g/dL
  Hematocrit: 30.0
 
  a. All are normal.
  b. All are decreased.
  c. Hemoglobin is elevated and other two are normal.
  d. Values do not agree with the rule of three.

[matt95]

Answer to Question 1

ANS: B
The MCV, which uses the hematocrit and red cell count for its calculation, appears to be reasonable. However, both the MCH and MCHC are extremely elevated, suggesting the parameter in error is common to both of them. This is the hemoglobin. A falsely increased hemoglobin will elevate both the MCH and MCHC because hemoglobin is in the numerator for both calculations.

Answer to Question 2

ANS: D
The rule of three suggests that the hematocrit (3 x hemoglobin). For this example, the hematocrit (3 x 16.0) 48 30.0. Therefore one of the values has to be invalid unless the red cell morphology is abnormal. However, in this instance no red cell morphology supports these results (mean cell hemoglobin concentration MCHC = 16/30  100 = 53 g/dL, which is impossible). Note: An expansion of the rule of three states that the hematocrit 9 x RBC count 9 x 3.22 27. In this case, some agreement exists between the two values. Thus just from the information given in this question, it appears that the incorrect value is the hemoglobin.

[waynest]

Excellent

[Viet Thy]

TYSM