Body Fluids

Question 1

Briefly discuss the clinical significance of abnormal CSF appearance, including the typical appearance of CSF from a traumatic tap and from a patient with a subarachnoid
hemorrhage.

Answer 1

Subarachnoid hemorrhage:
- Blood is evenly distributed in all four (4) tubes
Traumatic tap
- NO xanthochromia; this is fresh blood
- degree of “redness” decreases as the collection of tubes
progresses
- Red cell button present after centrifugation

Question 2

Clinical Significance of CSF Appearance
- Crystal clear

Answer 2

Significance
- Normal

Question 3

Clinical Significance of CSF Appearance
- Hazy, turbid, cloudy, milky

Answer 3

Cause
- WBCs, RBCs, Microorganisms
Significance
- Meningitis, Hemorrhage, Traumatic tap

Question 4

Clinical Significance of CSF Appearance
- Bloody

Answer 4

Cause
- RBCs
Significance
- Hemorrhage

Question 5

Clinical Significance of CSF Appearance
- Xanthochromic

Answer 5

Cause
- Hemoglobin, Bilirubin
Significance
- Old hemorrhage, elevated bilirubin

Question 6

Clinical Significance of CSF Appearance
- Clotted

Answer 6

Cause
- Clotting factors
Significance
- Introduced by traumatic tap

Question 7

Main cause of Xanthochromia in CSF?

Answer 7

Hemorrhage, subarachnoid or intracerebral

Question 8

Discuss the following aspects of CSF protein:
a. Four general conditions that cause its increase

Answer 8

1. Damage to the blood-brain barrier (i.e. skull fracture)
2. Inflammation (i.e. meningitis)
3. Increased endogenous production (i.e. MS)
4. Hemorrhage (stroke or aneurysm)

Question 9

Discuss the following aspects of CSF protein:
b. Two most common specific causes of its increase

Answer 9

1. Inflammation causing increased capillary permeability (i.e. meningitis)
2. Hemorrhage

Question 10

Discuss the following aspects of CSF protein:
c. Fraction that is in greatest concentration

Answer 10

Albumin

Question 11

Discuss the following aspects of CSF protein:
d. Reason for its spurious elevation

Answer 11

When CSF is contaminated with serum or blood during traumatic tap

Question 12

State the clinical significance of an increased CSF IgG index calculation.

Answer 12

Increased in multiple sclerosis (due to the increase of IgG in the CSF)

Question 13

State the normal proportion of CSF glucose related to concomitant blood glucose measurements.

Answer 13

60-70% of concomitant blood glucose

Question 14

State the specific clinical significance of CSF lactate measurements.

Answer 14

Increased in any condition that decreases oxygen blood flow to the brain

> 25 mg/dL indicates bacterial, tubercular, or fungal meningitis

Question 15

Describe the interaction of the three processes involved in the normal formation of serous fluid (colloid osmotic pressure, hydrostatic pressure, and capillary permeability).

Answer 15

Colloid osmotic pressure: the pressure caused by protein

Hydrostatic pressure: exerted by the pumping heart

Capillary permeability: the normal ability of water and small molecules in the intravascular space to pass into extravascular space and lymph while preventing the macromolecules and cells from doing so

Question 16

State whether increased or decreased colloid osmotic pressure, hydrostatic pressure, and capillary permeability cause the formation of effusions.

Answer 16

Increased capillary permeability
Increased hydrostatic pressure
Decreased colloid osmotic pressure
Decreased lymphatic absorption

Question 17

Differentiate transudates and exudates in detail according to typical causes for each condition and the following specific laboratory values:
a. Appearance
b. Specific gravity
c. Total protein
d. Lactate dehydrogenase
e. Cell count
f. Presence of spontaneous clotting

Answer 17

Transudate: increased hydrostatic pressure and decreased colloid osmotic pressure (fluid leakage)
Exudate: increased capillary permeability (fluid and protein leakage)

Transudate vs. Exudate
a. Clear vs. Cloudy
b. < 1.015 vs. > 1.015
c. < 3.0 vs. > 3.0
d. < 200 vs. > 200
e. < 1000 vs. > 1000
f. No vs. Possible

Question 18

Recognize the clinical significance of pleural fluid glucose, pH, and amylase determinations, including detailed differential diagnoses obtained at specific pH levels.

Answer 18

Glucose: decreased in tubercular and rheumatoid inflammations
Amylase: Elevated in pancreatic disorders

pH <6.0: Esophageal rupture
pH <7.2: Antibiotics and chest tube drainage
pH >7.4: Malignancy

Question 19

Recognize the specific clinical significance of pericardial fluid glucose and CEA determinations.

Answer 19

Glucose: decreased in bacterial infections and malignancy
Carcinoembryonic antigen (CEA): indicates malignancy

Question 20

Obj. 14

Answer 20

Glucose: If markedly decreased, indicates Group II or III disorders
Lactase: If <7.5, septic arthritis is excluded; if >7.5, septic or rheumatoid arthritis are indicated
Total Protein: Increased in inflammatory or hemorrhagic disorders
Uric acid: May indicate crystal-induced joint disorder, such as gout, when uric acid crystals are not seen on crystal examination

Question 21

Obj. 15

Answer 21

Urine:
High levels of urea and creatinine
Normal (negative) levels of glucose and protein
Amniotic Fluid:
Plasma levels of urea and creatinine
Plasma levels of glucose and protein

Question 22

Obj. 16

Answer 22

1. Bilirubin spectral scan
2. Alpha fetoprotein
3. DNA analysis for chromosomal abnormalities
4. Change in OD at 450 nm determines the severity of hemolytic disease of the newborn
5. Assess neural tube disorders (i.e. spina bifida and anencephaly)
6. Down syndrome (Trisomy), etc

Question 23

Obj. 17

Answer 23

1. Lecithin/Sphingomyelin (L/S) ratio
2. Phosphatidylglycerol (PG) and Phosphatidylinositol (PI)
3. Foam stability index
4. Lamellar Body Counts
5. An L/S ratio of greater than 2.0 together with the presence of PG may suggest mature fetal lung development

Question 24

Obj. 18

Answer 24

a. 450 nm
b. Protect from light – at a certain wavelength of light, bilirubin can be metabolized into a different compound leading to a falsely lowered result