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CSF Glucose
CLINICAL USE
↑ in hyperglycemia;
↓ in CNS infection (bacterial meningitis);
Normal in viral meningitis;
Normal or ↓ in fungal meningitis
SPECIMEN
Sterile Container
VOLUME
Atleast 1 ml
Atleast 1 ml
TURN-AROUND TIME
4 hours
2 hours
NOTES
CSF Analysis
For Cerebrospinal fluid, the minimum required volume for quantitative examination is 1,000µl or 1 ml.
The necessity for simultaneous serum glucose should be considered, which is best obtained 2-4hrs before lumbar puncture.
The CSF specimen is usually divided into three serially collected sterile tubes:
Tube 1, for Chemistry and Immunology.
Tube 2, for Microbiology.
Tube 3, for Cell Count and Differential. An additional tube may be inserted in the No.3 position for Cytology, if a malignancy is suspected.
Under certain conditions, some variations are critical. For example, if Tube 1 is hemorrhagic because of a traumatic puncture, it should not be used when protein studies is the most important aspect of analysis.
Indeed, Tube 3 should be examined for the major purpose of the CSF collection.
The only definite statement is that Tube 1 should never be used for Microbiology due to contamination of skin bacteria.