Body Fluids Flashcards
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.
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
Clinical Significance of CSF Appearance
- Crystal clear
Significance
- Normal
Clinical Significance of CSF Appearance
- Hazy, turbid, cloudy, milky
Cause
- WBCs, RBCs, Microorganisms
Significance
- Meningitis, Hemorrhage, Traumatic tap
Clinical Significance of CSF Appearance
- Bloody
Cause
- RBCs
Significance
- Hemorrhage
Clinical Significance of CSF Appearance
- Xanthochromic
Cause
- Hemoglobin, Bilirubin
Significance
- Old hemorrhage, elevated bilirubin
Clinical Significance of CSF Appearance
- Clotted
Cause
- Clotting factors
Significance
- Introduced by traumatic tap
Main cause of Xanthochromia in CSF?
Hemorrhage, subarachnoid or intracerebral
Discuss the following aspects of CSF protein:
a. Four general conditions that cause its increase
- Damage to the blood-brain barrier (i.e. skull fracture)
- Inflammation (i.e. meningitis)
- Increased endogenous production (i.e. MS)
- Hemorrhage (stroke or aneurysm)
Discuss the following aspects of CSF protein:
b. Two most common specific causes of its increase
- Inflammation causing increased capillary permeability (i.e. meningitis)
- Hemorrhage
Discuss the following aspects of CSF protein:
c. Fraction that is in greatest concentration
Albumin
Discuss the following aspects of CSF protein:
d. Reason for its spurious elevation
When CSF is contaminated with serum or blood during traumatic tap
State the clinical significance of an increased CSF IgG index calculation.
Increased in multiple sclerosis (due to the increase of IgG in the CSF)
State the normal proportion of CSF glucose related to concomitant blood glucose measurements.
60-70% of concomitant blood glucose
State the specific clinical significance of CSF lactate measurements.
Increased in any condition that decreases oxygen blood flow to the brain
> 25 mg/dL indicates bacterial, tubercular, or fungal meningitis
Describe the interaction of the three processes involved in the normal formation of serous fluid (colloid osmotic pressure, hydrostatic pressure, and capillary permeability).
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
State whether increased or decreased colloid osmotic pressure, hydrostatic pressure, and capillary permeability cause the formation of effusions.
Increased capillary permeability
Increased hydrostatic pressure
Decreased colloid osmotic pressure
Decreased lymphatic absorption
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
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
Recognize the clinical significance of pleural fluid glucose, pH, and amylase determinations, including detailed differential diagnoses obtained at specific pH levels.
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
Recognize the specific clinical significance of pericardial fluid glucose and CEA determinations.
Glucose: decreased in bacterial infections and malignancy
Carcinoembryonic antigen (CEA): indicates malignancy
Obj. 14
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
Obj. 15
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
Obj. 16
- Bilirubin spectral scan
- Alpha fetoprotein
- DNA analysis for chromosomal abnormalities
- Change in OD at 450 nm determines the severity of hemolytic disease of the newborn
- Assess neural tube disorders (i.e. spina bifida and anencephaly)
- Down syndrome (Trisomy), etc
Obj. 17
- Lecithin/Sphingomyelin (L/S) ratio
- Phosphatidylglycerol (PG) and Phosphatidylinositol (PI)
- Foam stability index
- Lamellar Body Counts
- An L/S ratio of greater than 2.0 together with the presence of PG may suggest mature fetal lung development
Obj. 18
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
