CLINICAL LAB SCIENEC

CHAPTER 12: PROCEDURES FOR URINALYSIS AND BODY FLUIDS 319
the sample obtained. Results obtained are in mg/dL. A dL is 0.1 of a liter (L). The total
volume is divided by 100 to obtain the number of dLs in a 24-hour sample.
URINALYSIS AND BODY FLUIDS ANALYSIS PROCEDURE #8
Cerebrospinal Fluid Examination and Cell Counts
Principles
The presence of RBCs and WBCs above minimal levels in CSF is significant. CSF levels
of protein and glucose are indicative of bacterial and viral infections, based on
which constituent is elevated or decreased. Both protein and glucose levels in CSF
are slightly lower than the levels found in the blood under normal circumstances.
Normal CSF values are as follows:
Cell counts
< 5 × 106/L for mononuclear WBCs and RBCs
Glucose
60% to 70% of plasma levels (usually at 50–80 mg/dL or 2.8–4.4 mmol/L)
but may vary slightly with methodology used for measurement
Protein
Infant = 0.1–1.2 g/L; adult = 0.15–0.45 g/L
IgG/albumin ratio <0.2
CSF analysis procedures are useful in diagnosing bacterial, viral, or fungal meningitis;
encephalitis; malignant infiltrates such as acute leukemias and lymphomas;
multiple sclerosis; and subarachnoid hemorrhage.
Specimen Collection and Preparation
A 5 mL to 15 mL specimen of CSF divided between three plain sterile tubes should
be used. A minimum of 2 mL is required for immunoglobulin analysis if it is to be
performed. Centrifuge all specimens containing RBCs or particulate matter.
Red and White Cell Enumerations
Unless the counts are extremely elevated for RBCs and WBCs, these counts are performed
undiluted on a hemacytometer (Figures 12-39, 12-40, and 12-41).
Equipment and Supplies
1. Gloves, disposable paper towels and disinfectant or other cleaning solution
2. Report form for recording results
FIGURE 12-39 Top view of hemacytometer with cover slip in place.
Source: Delmar/Cengage Learning.
FIGURE 12-40 Side view of hemacytometer.
Source: Delmar/Cengage Learning.
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