L35 Miscellaneous fluids Flashcards
What are the tests in general we can do to examine fluids like pleural fluid, CSF, etc.? (5)
- Appearance
- Biochemistry
- Cell count and differential
- Microbiology
- Cytology
What is transudate (1), main difference from exudate (1) and state all the causes of transudate formation. (8)
Fluid with low protein content which accumulates
Protein <30 g/l
- Increased hydrostatic pressure
- congestive heart failure
- liver cirrhosis
- portal hypertension (ascites) - Decreased oncotic pressure
- nephrotic syndrome
- cirrhosis with hypoalbuminemia
- protein malabsorption
- protein losing enteropathy - Decreased drainage:
- lymphatic obstruction
What is exudate (1), main difference from exudate (1) and state all the causes of exudate in pleural fluid (3) and ascitic fluid (3)
Exudate is fluid with high protein content which accumulates due to increased capillary permeability
Protein >30g/L
- Pleural fluid
- Pneumonia
- Malignancy
- Vasculitis - Ascitic fluid
- Pancreatitis
- Peritonitis
- Malignancy
CSF is produced by the __________ and it is an ultra filtrate of plasma with ________ secretions.
choroid plexus;
intrathecal (= spinal canal)
How is CSF collected?
What color of the CSF is preferred?
- Lumbar puncture at L4/L5
- Clear specimen is preferred;
blood causes false elevation of CSF protein
State the cause of the coloured CSF below
A. Blood-stained
B. Yellow
C. Turbid
A: recent subarachnoid hemorrhage, traumatic tap
B. xanthrochromic: SAH >12h, jaundice
C. presence of WBC
Pleural fluid is from the ________ of the lung, and it is collected by?
interstitial space;
pleural tap/ thoracocentesis (same)
State the cause of the coloured pleural fluid below A. Straw colored B. Blood-stained C. Purulent/turbid D. Chylous
A: transudate from Congestive heart failure
B. malignancy, vasculitis
C. bacterial infection
D. cholesterol > lymphatic leakage (from thoracic duct)/ obstruction
Ascites is the accumulation of excess fluid in the ______________. MC is cirrhosis > malignancy > CHF.
It can be collected by?
peritoneal cavity;
paracentesis
State the cause of the coloured ascitic fluid below A. Straw colored B. Blood-stained C. Purulent/turbid D. Chylous
A: Congestive heart failure, cirrhosis
B: malignancy, hemorrhagic pancreatitis
C. peritonitis
D. cholesterol > lymphatic leakage (from thoracic duct)/ obstruction
What is the normal percentage of plasma glucose should the CSF have?
> 60%, thus requiring concurrent plasma glucose sample
What may a decreased <50% glucose in CSF indicate? (4)
- Bacterial meningitis
- increase in WBC,
- malignant infiltration,
- traumatic tap
NOT viral! *bacterial can use up the glucose, highly metabolically active cells use up glucose
To delineate viral and bacterial causes of meningitis, we can use level of _____________ which is elevated in __________ only.
Procalcitonin;
bacterial meningitis
(in addition to decreased glucose in CSF)
CSF total protein should be less than?
If there is an increase, it indicates?
<0.7g/L;
- infection (increase Ig)
- malignant infiltration
- chronic inflammation (MS, GBS)
- spinal canal blockage
- false positive traumatic tap
If CSF protein is very high, what should be done to rule out false positively high protein by traumatic tap?
Red cell count
CSF lactate is increased in ?
But it has no added advantage compared to seeing CSF glucose.
It is not commonly done
bacterial meningitis
not in viral
Asialo-transferrin is transferrin without sialic acid.
Where is asialo-transferrin found? When do we have to check CSF asiago-transferrin?
CSF, aqueous and vitreous humor;
To differentiate CSF rhinorrhea from nasal secretion
What do we do after taking a pleural tap in a patient with pleural effusion? （5）
Use Light’s criteria to determine whether it is transudate of exudate.
- Compare serum and pleural fluid protein, LDH.
Fluid is exudate if any one of the following criterion is met:
- Pleural: Serum protein > 0.5
- Pleural: Serum LDH > 0.6
- Pleural LDH > 2/3 of upper limit of serum LDH
If there is lipids in the pleural fluid, it indicates? (2), what appearance of the pleural fluid?
Lymphatic leakage
- rich in chylomicrons, thus high level of TG in chylous effusion
Adenosine deaminase (ADA) in pleural fluid is checked because it is specific for?
TB
How do we determine whether the ascitic fluid is exudate or transudate?
- Total protein in ascitic fluid
- Transudate <30 g/L
- Exudate >30 g/L - Serum-ascites albumin gradient (SAAG)
= serum albumin - ascitic fluid albumin
- Transudate >11g/L
- Exudate <11g/L
if high SAAG - likely to be portal HT
(hepatic sinusoid is designed to keep albumin in blood)
What are the possible causes for exudate and transudate in ascites? (6)
Transudate: portal hypertension causes
- cirrhosis
- heart failure
- portal vein thrombosis
Exudate:
- Pancreatitis
- Bacterial Peritonitis
- Malignancy
Glucose in ascitic fluid is usually not checked,
glucose is low in transdute/exudate?
List some examples of it.
Exudate
e.g. Bacterial peritonitis, malignant perfusion, TB
Amylase content in ascitic fluid is increased in what diseases? (3)
- Pancreatitis (a lot)
- Rupture of pancreatic pseudocyst
- Perforated peptic ulcer
Lipid is checked when we suspect __________ ascites.
Chylous
Name the common causes of ascites, in descending order.
Cirrhosis > Malignancy > CHF
Increased protein,
decreased glucose,
with neutrophils in the CSF.
Ddx?
How does it appear on Gram stain?
What color do you except the CSF sample to be?
Bacterial meningitis!
- glucose decreased because bacteria used up
- total protein increased due to increased capillary permeability for WBCs to fight off bacteria
Gram+
Turbid
Which of the following regarding viral meningitis is incorrect? A. The White cell count is increased B. The WBC differential is normal C. The glucose level is normal D. Neutrophils can be found in the CSF E. It appears to be clear F. Gram stain -ve
D is incorrect: should be lymphocytes!
_______ bottle is used when in collecting ascitic fluid.
Fluoride bottle
