Body Fluids Flashcards
What are the major functions of cerebrospinal fluid?
- physiological system to supply nutrients to central nervous system
- remove metabolic waste
- mechanical barrier to cushion brain and spinal cord from trauma
What is the normal volume of cerebrospinal fluid?
140 -170 mL
Where does the cerebrospinal fluid flow?
in the subarachnoid space between the pia mater and arachnoid
What is the purpose of the blood-brain barrier?
protects and restricts entry of macromolecular from blood to cerebrospinal fluid to brain
How is cerebrospinal fluid collected?
by lumbar puncture beneath third, fourth, or fifth vertebrae
What cerebrospinal fluid tubes belong to which department?
1: Chemistry/Serology
2: Microbiology
3: Hematology Cell Count
4: Cytology/Extra
How should you handle a cerebrospinal fluid collection if it cannot done be done STAT?
Hematology: Refrigerated
Chemistry: Frozen
Microbiology: Room Temperature
What does a clear cerebrospinal fluid indicate?
normal
What does a cloudy/turbid/milky cerebrospinal fluid indicate?
- protein or lipid
- WBC/Bacteria from Meningitis
- RBC from Hemorrhage/Traumatic Tap
What does a xanthochromia cerebrospinal fluid indicate?
- supernatant with pink/orange/yellow color
- RBC Degradation
- others: increased bilirubin or protein concentration, presence of carotene or melanoma pigment
How would a subarachnoid hemorrhage affect the cerebrospinal fluid?
- xanthochromia present in all tubes
- blood cerebrospinal fluid caused by intracranial hemorrhage does not contain enough fibrinogen to clot
- presence of macrophages containing ingested RBCs or hemosiderin granules
- positive D-Dimer indicates formation of fibrin at hemorrhage site
How would a traumatic tap affect the cerebrospinal fluid?
- uneven distribution of blood between four tubes
- clot formation from plasma fibrinogen leaking into cerebrospinal fluid
- supernatant usually clear
What are the normal cell counts for cerebrospinal fluid?
- 0-5 WBC/uL in adults
- 0-30 mononuclear cells/uL in neonates
Why do you need to perform cerebrospinal fluid immediately?
WBC/RBC begin to lyse in less than an hour, 40% of granulocytes disintegrate after two hours
What is the hemocytometer calculation equation?
(cells counted x dilution)/(# of squares x 0.1 uL)
What are the normal findings in cerebrospinal fluid?
no RBC, 0-5 lymphocytes and/or monocytes, ependymal cells
What are the abnormal findings in cerebrospinal fluid?
any RBCs, RBCs ingested in macrophages, WBC>5, neutrophils, blasts, malignant cells, plasma cells, reactive lymphocytes, eosinophils, bacteria, fungi, hemosiderin
What disease states are associated with increased lymphocytes?
HIV & AIDS, multiple sclerosis, viral infections
What disease states are associated with increased eosinophils?
parasitic infections, fungal infections
What disease states are associated with increased neutrophils?
meningitis, repeated lumbar punctures, injection of medications/dyes
What disease states are associated with increased macrophages?
appear 2-4 hours after RBCs enter cerebrospinal fluid, previous hemorrhage
What is a normal protein level in cerebrospinal fluid?
15-45 mg/dL in adults; higher in infant/elderly
What is the most abundant protein found in cerebrospinal fluid?
albumin
What does decreased protein in cerebrospinal fluid?
fluid leaking from central nervous system
What does increased protein in cerebrospinal fluid?
- damage to blood-brain barrier (meningitis, hemorrhage)
- immunoglobulin production in central nervous system
- decreased clearance of normal protein
- degradation of neural tissue
What is considered a normal value for plasma glucose?
60-70% of plasma glucose (plasma glucose of 1000 mg/dL would have a normal cerebrospinal fluid glucose of 65 mg/dL)
What does an elevated serum glucose indicate?
elevated cerebrospinal fluid glucose
What does a decreased cerebrospinal fluid glucose help determine?
causative agent of meningitis
What does a decreased glucose, increased leukocytes with neutrophils in cerebrospinal fluid indicate?
bacterial
What does a decreased glucose, increased leukocytes with lymphocytes in cerebrospinal fluid indicate?
tubercular
What does a normal glucose with increased leukocyte with lymphocytes in cerebrospinal fluid indicate?
viral
What significant values show up in bacterial meningitis?
increase in neutrophils, low cerebrospinal fluid glucose, high cerebrospinal fluid lactate, high cerebrospinal fluid protein
What significant values show up in viral meningitis?
increase in lymphocytes and monocytes, normal cerebrospinal fluid glucose, normal cerebrospinal fluid lactate
What are serous fluids?
closed cavities of body lined with two serous membranes; serous fluid beneath membranes provide lubrication as surfaces move
What is parietal fluid?
fluid that lines cavity wall
What is visceral fluid?
fluid that covers organs within cavity
How is serous fluid formed?
ultrafiltrates of plasma; production and reabsorption subject to hydrostatic and oncotic pressure from capillaries serving the cavity
What is effusion?
increase in fluid beneath membranes due to disruption in serous fluid formation and reabsorption
What causes effusion?
increased hydrostatic pressure, increased capillary permeability (inflammation/infection), decreased oncotic pressure (hypoproteinemia in nephrotic syndrome), lymphatic obstructions (tumors)
Where is pleural fluid?
lungs/chest
Where is peritoneal fluid?
abdominal
Where is pericardial fluid?
heart
What preservatives are used for serous fluid?
EDTA and heparin
What are transudates?
- effusion due to change in hydrostatic pressure
- fluid leaks out of blood vessels into body cavities
What are exudates?
- effusion due to inflammation
- enlarged vessels allow fluid and protein to leak out into body cavities
What helps determine if a fluid is a transudate or exudate?
- serum total protein ratio
- serum LD ratio
What results do transudates present?
clear, low cell count, low LDH
What results do exudates present?
cloudy/bloody, high cell count, high LDH
What does normal and transudative fluid look like?
clear to pale yellow
Why could pleural fluid be turbid?
WBCs indicating infection, tuberculosis, immunological disorder
What does a bloody pleural fluid indicate?
signifies trauma, membrane damage (malignancy), traumatic draw
What does a milky pleural fluid indicate?
chylous material from thoracic duct leakage or pseudochylous material from chronic inflammatory conditions
What does it mean when lymphocytes are found in pleural fluid?
normal in transudates and exudates, increase in tuberculosis, viral infections, malignancy, autoimmune disorder (lupus)
What does it mean when neutrophils are found in pleural fluid?
increased bacterial infection (pneumonia), pancreatitis, pulmonary infarction
What does it mean when eosinophils are found in pleural fluid?
trauma, allergy, parasitic infections
What does a decreased glucose in pleural fluid indicate?
rheumatoid inflammation or purulent infection
What does a pH <7.3 in pleural fluid indicate?
need to chest-tube drainage, antibiotics for pneumonia
What does a pH <6.0 in pleural fluid indicate?
esophageal rupture with influx of gastric fluid
What does an increase in amylase in pleural fluid indicate?
pancreatitis, esophageal rupture, malignancy
What are the common bacteria in pleural effusions?
Staphylococcus aureus, Enterobacteriaceae, Anaerobes, Mycobacterium tuberculosis
What are some common tests used for pleural fluid?
gram stain, acid-fast stains, anaerobic/aerobic cultures, mycobacterium cultures
What is the normal amount for pericardial fluid?
10-50 mL
What are pericardial effusions caused by?
pericarditis, malignancy, trauma, metabolic disorders (uremia)
What does a normal pericardial fluid look like?
clear to pale yellow
What does a turbid pericardial fluid indicate?
infections or malignancy (with blood)
What does a grossly bloody pericardial fluid indicate?
cardiac puncture, anticoagulant misuse
What does a milky pericardial fluid indicate?
chylous/pseudochylous effusion
What is the normal appearance of peritoneal fluid?
clear to pale-yellow
What does a decrease in glucose of peritoneal fluid indicate?
tubercular peritonitis, malignancy
What does an increase in amylase of peritoneal fluid indicate?
pancreatitis
What does an increase in alkaline phosphatase of peritoneal fluid indicate?
intestinal perforation
What are normal cell types found in peritoneal fluid?
abundant mesothelial cells, macrophages, lipophages, leukocytes
What does peritoneal fluid in malignancy of gastrointestinal or ovarian origin look like?
WBCs with mucin-filled vacuoles, psammoma bodies of collagen-like material
What is synovial fluid?
found in all moveable joints beneath articular cartilage lining bones
What are the functions of synovial fluid?
lubrication of joints, lessen bone compression during walking/jogging, provide nutrients to articular cartilage
What happens in arthritis?
damage to articular membranes producing pain or stiffness
What is arthritis caused by?
infection, inflammation, metabolic disorders, trauma, stress
What are the four classification groups of arthritis?
noninflammatory, inflammatory, septic, hemorrhagic
What is associated with noninflammatory arthritis?
degenerative joint disorders
What is associated with inflammatory arthritis?
rheumatoid arthritis, lupus erythematosus, crystal-induced gout, pseudogout
What is associated with septic arthritis?
microbial infection
What is associated with hemorrhagic arthritis?
traumatic injury, coagulation deficiencies
What happens in osteoarthritis?
bone ends rub together and thinned cartilage
What happens in rheumatoid arthritis?
swollen inflamed synovial membrane and bone erosion
How is synovial fluid collected?
by needle aspiration called arthrocentesis
How is synovial fluid distributed?
into three tubes
- heparinized for microbiology
- EDTA for hematology
- nonanticoagulated - crystal (no powdered anticoagulants) for chemical/serological testing
What is the normal appearance of synovial fluid?
pale yellow and clear; deeper yellow seen in inflammation
What causes a bloody appearance to synovial fluid?
traumatic aspiration versus hemorrhagic arthritis (uneven distribution)
What causes synovial fluid to appear turbid?
WBCs, synovial debris, fibirn
What is the normal viscosity of synovial fluid?
4-6 cm string
What happens to the viscosity of synovial fluid in arthritis?
decreased viscosity
What is the normal leukocyte count of synovial fluid?
<200 cells/uL; primarily mononuclear cells with <20% PMNs and <15% lymphocytes
If there are increased PMNs in synovial fluid, what does that indicate?
septic condition
If there is an increased lymphocytes in synovial fluid, what does that indicate?
nonseptic inflammation
