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Methods
Parameter Key
HGB
Measured hemoglobin concentration
MCH
Mean Corpuscular Hemoglobin
MCHC
Mean Corpuscular Hemoglobin Concentration
Calculating the HGB Result Using CHCM
The Corpuscular Hemoglobin Concentration Mean (CHCM) and Mean
Corpuscular Hemoglobin Concentration (MCHC) both provide a measurement of
the average corpuscular hemoglobin concentration in the sample. The CHCM is a
directly measured parameter based on a cell-by-cell analysis, while the MCHC is
a calculated parameter based on the HGB, MCV, and RBC results.
If they differ by more than 1.9 g/dL, a Comparison Error MCHC / CHCM
(CHCMCE) sample/system flag alerts operators to a condition that could be
affecting one or more of the three results (RBC, MCV or HGB) used to calculate
MCHC.
For example, severe lipemia is a known interference that can falsely elevate a
HGB result obtained from the colorimetric hemoglobin method. When the
hemoglobin is falsely increased, the MCHC is also falsely increased.
Using CHCM to calculate HGB avoids this interference since CHCM is directly
measured and is virtually unaffected by lipemia. To calculate HGB, replace
MCHC with CHCM as follows:
MCHC = (HGB
÷
[RBC x MCV]) x 1000
HGB = (MCHC x RBC x MCV)
÷
1000
Calculated HGB = (CHCM x RBC x MCV)
÷
1000 or (CHCM x Hct)
÷
100
The Measured HGB and Calculated HGB values are displayed on the HGB panel
of the Run Screen.
Summary of Contents for ADVIA 2120
Page 1: ...ADVIA 2120 2120i Hematology Systems Operator s Guide 067D0157 01 Rev 201 0 ...
Page 30: ...1 26 Welcome to the ADVIA 2120 2120i Hematology System ...
Page 46: ...3 12 Daily Routine ...
Page 171: ...7 2 Status Line messages T 93 U 94 V 96 W 98 X 99 Y 99 Z 99 ...
Page 269: ...7 100 Status Line messages ...
Page 341: ...8 72 Methods ...