UA 7.3 Cerebrospinal, Serous, and Synovial Fluids Flashcards
- Cerebrospinal fluid (CSF) is formed by ultrafiltration of plasma through the:
A. Choroid plexus
B. Sagittal sinus
C. Anterior cerebral lymphatics
D. Arachnoid membrane
A. Choroid plexus
- Which statement regarding CSF is true?
A. Normal values for mononuclear cells are higher for infants than for adults
B. Absolute neutrophilia is not significant if the total WBC count is less than 25/µL
C. The first aliquot of CSF should be sent to the microbiology laboratory
D. Neutrophils compose the majority of WBCs in normal CSF
A. Normal values for mononuclear cells are higher for infants than for adults
- When collecting CSF, a difference between opening and closing fluid pressure greater than 100 mm H2O indicates:
A. Low CSF volume
B. Subarachnoid hemorrhage
C. Meningitis
D. Hydrocephalus
A. Low CSF volume
- Which of the following findings is consistent with a subarachnoid hemorrhage rather than a traumatic tap?
A. Clearing of the fluid as it is aspirated
B. A clear supernatant after centrifugation
C. Xanthochromia
D. Presence of a protein in the sample
C. Xanthochromia
- The term used to denote a high WBC count in the CSF is:
A. Empyema
B. Neutrophilia
C. Pleocytosis
D. Hyperglycorrhachia
C. Pleocytosis
- Which of the adult CSF values in the table below are consistent with bacterial meningitis?
A. WBCs: 50/μL
Lymphocytes: 44%
Monocytes: 55%
Eosinophils: 0%
Neutrophils: 0%
Neuroectodermal Cells: 1%
B. WBCs: 300/μL
Lymphocytes: 75%
Monocytes: 21%
Eosinophils: 3%
Neutrophils: 0%
Neuroectodermal Cells: 1%
C. WBCs: 2,000/μL
Lymphocytes: 5%
Monocytes: 15%
Eosinophils: 0%
Neutrophils: 80%
Neuroectodermal Cells: 0%μL
D. WBCs: 2,500/μL
Lymphocytes: 40%
Monocytes: 50%
Eosinophils: 0%
Neutrophils: 10%
Neuroectodermal Cells: 0%
C. WBCs: 2,000/μL
Lymphocytes: 5%
Monocytes: 15%
Eosinophils: 0%
Neutrophils: 80%
Neuroectodermal Cells: 0%μL
- Given the following data, determine the corrected CSF WBC count.
RBCs
CSF: 6,000/μL
Peripheral Blood: 4.0 × 10^6/μL
WBCs
CSF: 150/μL
Peripheral Blood: 5.0 × 10^3/μL
A. 8/µL
B. 142/µL
C. 120/µL
D. 145/µL
B. 142/µL
Corrected WBC count = WBCs in CSF – [(Blood WBCs × CSF RBCs) ÷ Blood RBCs]
Corrected WBC count = 150/µL – [(5,000/µL WBCs × 6,000/µL RBCs) ÷ 4,000,000/µL RBCs]
Corrected WBC count = 150/µL – 7.5/µL
Corrected WBC count = 142/µL
- SITUATION: What is the most likely cause of the following CSF results?
CSF glucose 20 mg/dL;
CSF protein 200 mg/dL;
CSF lactate 50 mg/dL (reference range 5–25 mg/dL)
A. Viral meningitis
B. Viral encephalitis
C. Cryptococcal meningitis
D. Acute bacterial meningitis
D. Acute bacterial meningitis
- Which of the following conditions is most often associated with normal CSF glucose and protein?
A. Multiple sclerosis
B. Malignancy
C. Subarachnoid hemorrhage
D. Viral meningitis
D. Viral meningitis
In viral (aseptic) meningitis, the CSF glucose is usually above 40 mg/dL and the total protein is normal or slightly increased.
- The diagnosis of MS is suggested by which finding?
A. The presence of elevated protein and low glucose
B. A decreased IgG index
C. The presence of oligoclonal bands by electrophoresis
D. An increased level of CSF β-microglobulin
C. The presence of oligoclonal bands by electrophoresis
- Which of the following results is consistent with fungal meningitis?
A. Normal CSF glucose
B. Pleocytosis of mixed cellularity
C. Normal CSF protein
D. High CSF lactate
B. Pleocytosis of mixed cellularity
- In what suspected condition should a wet prep using a warm slide be examined?
A. Cryptococcal meningitis
B. Amoebic meningoencephalitis
C. Mycobacterium tuberculosis infection
D. Neurosyphilis
B. Amoebic meningoencephalitis
- Which of the following CSF test results is most commonly increased in patients with MS?
A. Glutamine
B. Lactate
C. IgG index
D. Ammonia
C. IgG index
- Which of the following is an inappropriate procedure for performing routine CSF analysis?
A. A differential is done only if the total WBC count is greater than 10/µL
B. A differential should be done on a stained CSF concentrate
C. A minimum of 30 WBCs should be differentiated
D. A Wright-stained slide should be examined, rather than a chamber differential
A. A differential is done only if the total WBC count is greater than 10/µL
A relative (percent) increase in PMNs may be significant even when the WBC count does not exceed the upper limit of normal. For this reason, a WBC differential using a concentrated CSF sample is always performed on neonates and when the WBC count is greater than 5/µL. Cytocentrifugation should be used to concentrate the cells followed by staining with the Wright stain.
- Which cell is present in CSF in greater numbers in newborns than in older children or adults?
A. Eosinophils
B. Lymphocytes
C. Monocytes
D. Neutrophils
C. Monocytes
- Neutrophilic pleocytosis is usually associated with all of the following except:
A. Cerebral infarction
B. Malignancy
C. Myelography
D. Neurosyphilis
D. Neurosyphilis
- Which statement about CSF protein is true?
A. An abnormal serum protein electrophoretic pattern does not affect the CSF pattern
B. The upper reference limit (URL) for CSF total protein in newborns is one half the adult level
C. CSF IgG is increased in panencephalitis, malignancy, and neurosyphilis
D. Antibodies to Treponema pallidum disappear after successful antibiotic therapy
C. CSF IgG is increased in panencephalitis, malignancy, and neurosyphilis
- Which of the following statements regarding routine microbiological examination of CSF is true?
A. A Gram stain is performed on the CSF prior to concentration
B. The Gram stain is positive in fewer than 40% of cases of acute bacterial meningitis
C. India ink and acid fast stains are indicated if neutrophilic pleocytosis is present
D. All CSF specimens should be cultured using sheep blood agar, chocolate agar, and supplemented broth
D. All CSF specimens should be cultured using sheep blood agar, chocolate agar, and supplemented broth
- Which organism is the most frequent cause of bacterial meningitis in neonates?
A. Neisseria meningitidis
B. Group B Streptococcus
C. Haemophilus influenzae
D. Klebsiella pneumoniae
B. Group B Streptococcus
- Following a head injury, which protein will identify the presence of CSF leakage through the nose?
A. Transthyretin
B. Myelin basic protein
C. Tau protein
D. C-reactive protein
C. Tau protein
- Which of the following statements regarding serous fluids is true?
A. The normal volume of pleural fluid is 30 to 50 mL
B. Mesothelial cells, PMNs, lymphocytes, and macrophages may be present in normal fluids
C. Radiography can detect a 10% increase in the volume of a serous fluid
D. Normal serous fluids are colorless
B. Mesothelial cells, PMNs, lymphocytes, and macrophages may be present in normal fluids
- The term effusion refers to:
A. A chest fluid that is purulent
B. A serous fluid that is chylous
C. An increased volume of serous fluid
D. An inflammatory process affecting the appearance of a serous fluid
C. An increased volume of serous fluid
Effusions are classified as either transudates, exudates, or chylous. Transudates result from abnormal hemodynamics (e.g., congestive heart failure, liver disease), and exudates and chylous fluids from local disease. Pleural fluid that is purulent is called empyemic fluid. Such fluid has a WBC count of 10,000/µL or greater.
- Which of the following laboratory results is characteristic of a transudative fluid?
A. SG = 1.018
B. Total protein = 3.2 g/dL
C. LD fluid/serum ratio = 0.25
D. Total protein fluid:serum ratio = 0.65
C. LD fluid/serum ratio = 0.25
- Which observation is least useful in distinguishing a hemorrhagic serous fluid from a traumatic tap?
A. Clearing of fluid as it is aspirated
B. Presence of xanthochromia
C. The formation of a clot
D. Diminished RBC count in successive aliquots
C. The formation of a clot
