Fluid Flashcards
What is CSF? (1) What are the normal CSF GLU & Protein compared to Plasma? (2) How about WBC differential in CSF? (2)
CSF is form by ultrafiltration of plasma through the choroid plexus, it returns to circulation via sagittal sinus
CSF protein: Trivial
CSF glucose: 0.6 plasma glucose
Infant M%>50%, Adult L%>50%
When you receive CSF as precious specimen, CSF Biochem is done at CMC, CSF cell count & gram stain are send out tests. Can I swap the sample for CHEM & sample for Micro? (1) How are they related to patient diagnosis? (2)
1st aliquot CSF send to CHEM as contamination is likely, 2nd aliquot sent to MICRO. They should not be swapped.
CSF Biochem test for Protein & Glucose
For patient CSF with Low GLU and High TP: SAH, MS, malignancy, bacterial (High Lactate) / fungal meningitis
CSF Cell count
High WBC indicates Infection, MS & leukemia
When RBC exist, WBC should be corrected by:
Corrected WBC count = WBCs in CSF – [(Blood WBCs × CSF RBCs) ÷ Blood RBCs]
DC is performed for WBC> 5/μL & newborn, Wright stain slide is prepared after concentrating CSF sample by Cytocentrifugation.
DC result is helpful in differentiating the type of infection:
N = bacterial, L = viral, both = TB/fungal
How can you tell SAH from traumatic tap? (1)
visual Xanthochromia for SAH
When CSF monocyte is high, we use wet preparations for amoeba, why? (1)
amoeba mimic monocytes. Living amoeba in wet preparation shows projections when facilitate its identification
Suggest 2 ways to diagnose MS. (2)
IgG index for screening
IgG index = (CSF/Plasma IgG) / (CSF/Plasma ALB) ; >0.85 = MS / infection
CSF SPE for diagnosis
gamma oligoclonal banding in CSF SPE in 90% MS patient
those band should be absent in serum SPE
State the common bacteria isolated in meningitis for Neonate, Children, and Elderly. (6)
Group B Streptococcus
E. coli
Haemophilus influenzae
S. pneumoniae
N. meningitidis
S. pneumoniae
What are the 4 main types of Effusion? (4)
transudates(CHF/Cirrhosis), exudates(infection), or chylous(local disease), pseudochylous(necrosis)
What is empyemic fluid? (1)
Fluid with high WBC
How can you decide if a fluid sample is exudate or not? (2)
Is having exudate means patient has infection? (3)
According to Light’s criteria:
fluid/plasma LDH > 0.6
fluid/plasma TP > 0.5
Other than infection, exudate can be caused by infarction, malignancy and RA
How can you decide if a fluid sample is chylous or not? (1)
What is the significance of chylous fluid existence? (2)
How about pseudochylous? (2)
fluid/plasma TG > 2
It suggests lymphatic obstruction caused by thoracic duct injury / lymphoma
high fluid CHO
It suggests necrosis
Interpret pleural fluid GLU, AMY, pH
Low GLU: RA, also in infection, cancer
High GLU: DM
High AMY: Pancreatitis
pH<6.3: Esophageal rupture
pH6.3~7.3: RA / SLE / Cancer / exudative bacterial pneumonia
Synovial fluid is viscous compared to other fluid, why? (1) What would you suspect for a synovial fluid sample that is not viscous? (1)
Viscosity is due to the existence of lubricant called hyaluronate
Loss of viscosity is related to inflammation (arthritis)
How to interpret synovial fluid GLU & TP? (2) Why is UA performed for synovial fluid? (1)
synovial fluid GLU = plasma GLU - 0.5
-1.4 suggest Inflammatory arthritis
-2.2 suggest septic arthritis
synovial fluid TP < plasma TP
High UA suggests gout
State the common bacteria isolated in septic arthritis for Child, Adult, and Elderly (5)
Haemophilus spp.
Staphylococcus spp.
Streptococcus spp.
N. gonorrhoeae
Staphylococcus spp.
