49498-9
LaboratoryLeukocytes [#/volume] in Blood by Estimate
Definition
In the Hematology world estimated cell counts have existed for many moons and they are reported either qualitatively or quantitatively and done strictly by blood smear review. Smear Estimated WBC and Platelet counts that aren't just reported as reduced/adequate/many that are actually estimated as a numeric result like an estimate of 4 K/cumm for WBC or 400 K/cumm for platelets. Like doing a retic count by counting so many fields on the smear type of estimate. This WBC estimate count is a manual quantitative count. We report a number. See laboratory procedure: A. WBC Count Smear Estimate: 1. Use the 50X oil immersion objective. 2. Count the number of both intact and disrupted WBCs in each of 10 microscopic fields in different areas of the slide where RBCs slightly overlap. Divide the total number by 10 to establish the mean number of WBCs/field and multiply this mean by 3,000 to get the estimated WBC count/mm³. Do not round off the mean, e.g., if the mean is 5.7 do not round off to 6 but leave the figure at one place past the decimal point for greater accuracy. 3. If the quantitative WBC count is <25,000, the estimated smear count should be within 1,500 cells of this figure. Estimate counts are less reliable at >25,000 cells/mm³. III. REFERENCES: A. A Color Atlas and Instruction Manual of Peripheral Blood Cells Morphology, by Barbara H. O'Connor, 1984, p. 20. B. Principles and Procedures, Barbara A. Brown, 6th Edition, 1993, p. 104.
LOINC 6-Axis Classification
Component
Leukocytes
Property
NCnc
Time Aspect
Pt
System
Bld
Scale Type
Qn
Method Type
Estimate
Details
Class
HEM/BC
Order/Observation
Observation
Short Name
WBC # Bld Est
Display Name
WBC Estimate (Bld) [#/Vol]
Related Names
Frequently Asked Questions
What is LOINC code 49498-9?
LOINC code 49498-9 identifies "Leukocytes [#/volume] in Blood by Estimate". In the Hematology world estimated cell counts have existed for many moons and they are reported either qualitatively or quantitatively and done strictly by blood smear review. Smear Estimated WBC and Platelet counts that aren't just reported as reduced/adequate/many that are actually estimated as a numeric result like an estimate of 4 K/cumm for WBC or 400 K/cumm for platelets. Like doing a retic count by counting so many fields on the smear type of estimate. This WBC estimate count is a manual quantitative count. We report a number. See laboratory procedure: A. WBC Count Smear Estimate: 1. Use the 50X oil immersion objective. 2. Count the number of both intact and disrupted WBCs in each of 10 microscopic fields in different areas of the slide where RBCs slightly overlap. Divide the total number by 10 to establish the mean number of WBCs/field and multiply this mean by 3,000 to get the estimated WBC count/mm³. Do not round off the mean, e.g., if the mean is 5.7 do not round off to 6 but leave the figure at one place past the decimal point for greater accuracy. 3. If the quantitative WBC count is <25,000, the estimated smear count should be within 1,500 cells of this figure. Estimate counts are less reliable at >25,000 cells/mm³. III. REFERENCES: A. A Color Atlas and Instruction Manual of Peripheral Blood Cells Morphology, by Barbara H. O'Connor, 1984, p. 20. B. Principles and Procedures, Barbara A. Brown, 6th Edition, 1993, p. 104.
What does 49498-9 measure?
This code measures Leukocytes in Bld. It belongs to the HEM/BC class in the LOINC classification.
What is LOINC?
LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.