06-Other Body Fluids (CSF, Pleural, Peritoneal, Pericardial, Synovial, Seminal Fluids)

Cerebrospinal fluid (CSF)

What body fluid surrounds and protects the brain and spinal cord?

Choroid plexus

What structure produces the majority of CSF?

Ventricular ependymal lining

What structure accounts for part of the remaining CSF production?

Cerebral subarachnoid space

What structure accounts for the remainder of CSF production besides the choroid plexus and ventricular ependymal lining?

Medial and lateral foramina

Through what openings does CSF leave the ventricles to enter the subarachnoid space?

Subarachnoid space

What space between the arachnoid and pia mater contains circulating CSF?

500 mL/day

Approximately how much CSF is produced by an adult each day?

0.3–0.4 mL/min

What is the approximate rate of CSF production in adults?

90–150 mL

What is the total volume of CSF in an adult?

25 mL

Approximately how much of the adult CSF volume is located in the ventricles?

10–60 mL

What is the total CSF volume range in neonates?

Support and protection

What are the major functions of CSF for the brain and spinal cord?

Nutrients

What does CSF supply to the CNS?

Metabolic waste removal

What does CSF help remove from the CNS?

Hypothalamic releasing factors

What type of factors can use CSF as a pathway?

Lumbar puncture

What is the most common method of CSF collection?

L3-L4 or L4-L5

Between which vertebrae is a lumbar puncture usually performed?

Cisternal puncture

What CSF collection method accesses the cisterna?

Lateral cervical puncture

What CSF collection method involves access through the lateral cervical region?

Ventricular cannula/shunt

What method can be used to obtain CSF directly from the ventricular system?

Intracranial pressure

What pressure is measured upon CSF puncture?

90–180 mm H₂O

What is the normal adult CSF opening pressure in the lateral decubitus position?

10–100 mm H₂O

What is the normal CSF opening pressure range in infants and young children?

6–8 years

At what age does children's CSF opening pressure generally reach the adult range?

250 mm H₂O

What CSF opening pressure is diagnostic of intracranial hypertension according to the file?

Intracranial hypertension

What condition is suggested by a CSF opening pressure greater than 250 mm H₂O?

Meningitis

What infection can cause increased CSF opening pressure?

Intracranial hemorrhage

What bleeding condition can cause increased CSF opening pressure?

Tumor

What space-occupying lesion can cause increased CSF opening pressure?

Herniation

What dangerous condition is suggested by a significant pressure drop after removing 1–2 mL of CSF?

Stop lumbar tap

What should be done immediately if there is a significant CSF pressure drop after removing 1–2 mL?

20 mL

What is the maximum CSF volume that can be collected during one spinal tap?

3 sterile tubes

What is the minimum number of sterile CSF tubes normally collected?

4th tube

What additional CSF tube is recommended when possible for special or additional testing?

Tube 1

Which CSF tube is designated for chemistry and serologic analysis?

Tube 2

Which CSF tube is designated for microbiological examination?

Tube 3

Which CSF tube is designated for cell count and differential count?

Tube 4

Which CSF tube is reserved for additional or special serologic tests?

Chemistry and serology

What is the main purpose of CSF tube 1?

Microbiology

What is the main purpose of CSF tube 2?

Hematology

What is the main purpose of CSF tube 3?

Additional serology

What is the main purpose of CSF tube 4?

CSF protein and glucose

What common chemistry tests are performed on tube 1?

Culture, Gram stain, AFB stain

What major microbiologic tests can be performed on tube 2?

Cell count and differential count

What tests are performed on tube 3?

VDRL, RPR, PCR

What special tests may be performed on tube 4?

Tube 1

Which tube is most affected by blood or bacterial contamination introduced during collection?

Tube 3

If tube 1 is hemorrhagic from a traumatic puncture, which tube should be used instead for CSF protein analysis?

Tube 1

Which CSF tube must NEVER be submitted for microbiologic studies because of possible skin contamination?

Within 1 hour

When should collected CSF ideally reach the laboratory and be processed?

Frozen

How should tube 1 be stored if immediate testing is not possible?

Room temperature

How should tube 2 be stored if immediate microbiologic testing is not possible?

Refrigerated

How should tube 3 be stored if immediate cell counting is not possible?

1–8°C

What temperature range is given for refrigerated tube 3?

Frozen

How should tube 4 be stored if additional serologic testing is delayed?

Fastidious organisms

Why must CSF tube 2 for microbiology NOT be refrigerated?

Crystal clear

What is the normal gross appearance of CSF?

Turbid/cloudy

What CSF appearance may indicate increased WBCs or RBCs?

Bloody

What CSF appearance can result from intracranial hemorrhage or a traumatic tap?

Xanthochromic

What term describes pigmented CSF that is pink, yellow, orange, or brown?

Pink/yellow

What pigment may cause pink or yellow xanthochromic CSF?

Hemoglobin

What substance causes pink or yellow xanthochromic CSF?

Bilirubin

What substance can cause yellow xanthochromic CSF?

Protein

What substance can contribute to yellow xanthochromic CSF?

Carotene

What substance causes orange xanthochromic CSF?

Melanin

What substance causes brown xanthochromic CSF?

Xanthochromia

What is the pale pink/yellow supernatant caused by RBC lysis and hemoglobin breakdown called?

2–4 hours

How soon after subarachnoid hemorrhage can oxyhemoglobin be detected by lumbar puncture?

12 hours

Up to how long after subarachnoid hemorrhage may oxyhemoglobin take to appear?

24–36 hours

When does CSF oxyhemoglobin intensity peak after subarachnoid hemorrhage?

4–8 days

How long after hemorrhage does CSF oxyhemoglobin generally take to disappear?

Evenly distributed blood

What finding across all CSF tubes suggests intracranial hemorrhage rather than traumatic tap?

Decreasing blood intensity

What finding across sequential CSF tubes suggests a traumatic tap?

Xanthochromic supernatant

What centrifugation finding supports intracranial hemorrhage?

Clear supernatant

What centrifugation finding is expected in a traumatic tap?

Erythrophagocytosis

What process involving macrophages contributes to xanthochromic supernatant after intracranial hemorrhage?

No clot

What happens to a CSF specimen from intracranial hemorrhage after centrifugation with respect to clot formation?

Clot formation

What can occur in a later tube during a traumatic tap because plasma fibrinogen was introduced?

Tube 4

Which tube may show a clot after a traumatic tap due to introduced plasma fibrinogen?

Tube 3

Which CSF tube is used for cell counting?

Improved Neubauer chamber

Which counting chamber can be used for manual CSF cell counting?

Fuchs-Rosenthal chamber

Which specialized counting chamber can be used for manual CSF cell counting?

Undiluted CSF

What specimen preparation is generally used for manual CSF cell counting?

0–5 cells/µL

What is the normal adult CSF WBC count?

0–30 cells/µL

What is the normal neonatal CSF WBC count?

None

How many RBCs are normally present in CSF?

Lymphocytes and monocytes

Which cells normally compose the WBC population of adult CSF?

70:30

What is the approximate normal lymphocyte-to-monocyte ratio in adult CSF?

Monocytes

Which mononuclear cell predominates in normal CSF of children?

80%

What percentage of monocytes may still be considered normal in children's CSF?

Blast cells

What abnormal CSF cells may be found in acute leukemia with CNS involvement?

Neutrophils

Which CSF cells may indicate bacterial infection?

Bacterial meningitis

What infection is suggested by increased CSF neutrophils?

15–45 mg/dL

What is the normal CSF protein concentration?

Albumin

What protein predominantly makes up CSF protein?

CSF protein concentration is approximately what percentage of plasma protein?

Meningeal/CNS disease

What does elevated CSF protein commonly indicate?

50–80 mg/dL

What is the normal CSF glucose concentration?

60%

CSF glucose is approximately what percentage of plasma glucose?

2 hours

How long before CSF sampling should blood glucose ideally be measured?