Body Fluid Flashcards
CSF
Liquid that surrounds the brain and spinal cord and flows in the subarachnoid space
Functions of CSF
1) Physical support and protection
2) Provision of controlled chemical environment to supply nutrients and removal of wastes
3) Intracerebral and extracerebral transport
Lumbar puncture is performed where?
L3/L4 and lower
CSF Tube order
Tube 1: Chemistry and serology
Tube 2: Microbiology
Tube 3: Hematology
Tube 4: extra or send out tests/cytology
Why do we collect a lumbar puncture and perform an investigation of CSF?
- for suspected CNS infection
- Demylinating disease
- Malignancy
- hemorrhage into CNS
Appearance of CSF
Color: colorless
Clarity: clear
NOTE
Cloudy: cellular particles and debris
Yellow: xanthochromia (blood is gone—older bleed)
Brown: old blood
Red: fresh blood
Traumatic tap gets clearer as tubes progress
What are the 4 main biochemical markers in CSF?
- Glucose
- Protein (total and specific)
- Lactate
- Glutamine
When should you collect a blood glucose when comparing glucose levels in CSF?
2-4 hours prior
T/F:
Increased CSF glucose levels are clinically significant
FALSE: it just confirms that there is hyperglycemia
What are the causes for decreased CSF glucose levels (hypoglycorrhachia)?
- Disorder in carrier-mediated transport of glucose into CSF
- Active metabolism of glucose by cells or organisms
- Increased metabolism by the CNS
___ in the CSF reflect selective ultrafiltration of the CSF BBB
Protein levels
T/F:
All proteins found in blood is found in CSF
TRUE, just in much lower levels
Total protein in CSF is ___-___% of plasma
0.5-1%
What are causes of decreased protein levels in CSF?
- Decreased dialysis of proteins from the plasma
- Increased protein loss (removal of excessive volumes of CSF)
- Leakage from a tear in the dura, CSF otorrhea (ear), or CSF rinorrhea (nose)
What are causes of increased levels of protein in CSF?
- Lysis of contaminant blood from traumatic tap
- Increased permeability of the epithelial membrane
- Increased production by CNS tissue
- Obstruction
- BBB becomes more permeable from bacterial or fungal infections
Albumin MUST cross the BBB because it is produced by the ___
Liver
What does a CSF serum albumin index of <9 indicate?
That the BBB is intact
What is the CSF serum albumin index equation?
(CSF albumin (mg/dL))/(Serum albumin (mg/dL))
T/F: IgG must cross the BBB to enter the CSF
FALSE: IgG can be produced by local synthesis from plasma cells within the CSF
What is the normal value of CSF IgG index?
<0.73
What does the IgG index aid in?
- Aids in the diagnosing demyelinating diseases - MS, SSPE
- MS is most common inflammatory demyelinating disease
What is the significance of seeing an oligoclonal band pattern in a CSF ELP
The presence of an oligoclonal band pattern supersede the report of normal protein levels and there is a cause for concern in the serum doesn’t show the same pattern.
Oligoclonal banding in the gamma region, involving a small number of IgG clones, are usually seen with MS or SSPE
What does testing for lactate tell us?
It is an indicator of anaerobic metabolism. Time critical and ideally collected in a NaFl tube
What does testing for Glutamine tell us?
Glutamine levels correlate to NH3 in the CNS and is elevated in patients with hepatic encephalopathy
What are serous fluids?
The fluid between two serous membranes:
pleural, pericardial, peritoneal
What is effusion?
The accumulation of serous fluid
What is transudate?
when there is a systemic disorder that disrupts fluid filtration, fluid reabsorption, or both
What is exudate?
Occurs during an inflammatory process that results in damage to blood vessel walls, body cavity membrane, or decreased re absorption by the lymphatic system.
What is thoracentesis?
The fluid that is removed when retrieving pleural fluid
When would retrieval of pericardial fluid be necessary?
Necessary if cultures are needed for infection or cytology for suspected malignancy
What is ascites?
Excess peritoneal fluid. Indicates disease
What is amniotic fluid?
Fluid that surrounds the fetus during gestation. There is ablance between production, clearance, fetal urination, and swallowing
What is amniocentesis?
An amniotic sac puncture to retrieve amniotic fluid. The process is ultrasound guided.
Why is amniotic fluid analyzed?
To look for congenital diseases, neural tube defects, hemolytic disease of the fetus, fetal pulmonary development
What are the two reasons for the development of hemolytic desease of the fetus and newborn?
- incompatibility between maternal and fetal blood
- maternal ab to fetal RBCs that cause a hemolytic reaction (bilirubin may appear in AF)
Neural tube defects are screened by looking for ___
AFP
What is the main reason to test amniotic fluid?
To asses fetal lung maturity and determine if there is sufficient phospholipids reflected in the AF to prevent alveolar collapse if the fetus was delivered.
What is sweat in babies goof to test for?
ONLY for cystic fibrosis, an autosomal recessive diroder that affects exocrine glands and causes electrolyte and mucus secretion abnormalities
What is the function of synovial fluid?
Lubricant for joints and transport medium for delivery of nutrients and removal of cell wastes
What needs to be done to synovial fluid before it is tested on?
Add hyaluronidase to break down the mucoprotein matrix
What tests are performed on synovial fluid?
TP (inflammation), glucose (infectious disorders dec glucose), uric acid (gout), Lactic Acid (septic arthritis)
What are the classifications of synovial fluid?
Normal
I (noninflammatory)
II (inflammatory)
III (septic)
IV (crystal induced)
V (hemorrahagic)
