Serous Fluid

fluid that is inside body cavities that don’t open

the parietal (outer) and visceral (inner) layer

pleural, pericardial, and peritoneal

visceral layer

mesothelial cells

to reduce friction against organs

covers lungs, heart, and abdominal organs (visceral membrane) and internal surfaces of body cavity wall (parietal membrane)

parietal layer

visceral layer that is directly on the organ

the peritoneum

absorbs broken down fat/lipids before entering back to blood

Rich in blood vessels and lymphatic vessels (because high in triglycerides, lipids, and fat)

from parietal and then absorbed back in visceral layer

1. permeability of capillaries in parietal membrane
2. hydrostatic pressure in these capillaries (BP)
3. oncotic pressure
4. absorption of fluid by lymphatic system

highly porous, facilitates movement into the membrane
Even though the parietal membrane is porous, it doesn’t allow large molecules to pass

oncotic pressure produced by plasma proteins in capillaries pull fluid to go backwards (where there is increased osmolality), force pushing backwards that makes sure not too much fluid is in the 'sack'

takes ~30% of fluid out (whereas the other 70% pass through the visceral membrane)

(blood pressure) forces plasma ultrafiltrate to form in the cavity

accumulation of fluid in a body cavity indicating an abnormal or pathologic process

Swollen knee

puncture of a body cavity for aspiration of fluid

obtains pleural fluid

obtain pericardial fluid

obtain peritoneal fluid

effusion in peritoneal cavity

same as peritoneal fluid

tubes 2 and 3, for microbio/microscopic exam

No anticoagulant -> clotting
Cell counts : cells that clot together cant be counted / read, leading to inaccurate results
microbio: bacteria's that clump together are uncounted, leading to false negative

because the specimen gets spun and testing is done on supernatant

maintain at room temp and transport to lab immediately

When using it ONLY for cell counts, to decrease the WBC lysis from occurring

because it can shock / kill bacteria

transudate or exudate

congestive heart failure

systemic diseases that cause an increase in hydrostatic pressure or decrease in plasma oncotic pressure

not enough pressure, blood fills up ventricle, backs up to atrium and then lungs, leading to fluid accumulation into lungs

Exudate

congestive heart failure (CHF) and nephrotic syndrome

because there is no fibrinogen (clotting protein) present, transudate isn't a problem with capillaries or permeability

inflammatory processes that increase permeability of capillary endothelium or a decrease in absorption by lymphatic system

infections, neoplasms, trauma, inflammatory conditions

because everything is compromised and damaged, allowing larger molecules like fibrinogen to enter

clear to pale yellow
viscosity similar to serum
does not clot (has no fibrinogen)

usually cloudy
various colors
may have shimmer or sheen
can form clots

Large # of WBC
other cells
chyle
lipids

chyle

exudate has higher WBC (moderate is transudate)

neutrophils

caused by obstruction of or damage to lymphatic system

chronic effusions, can be differentiated from chylous effusions by their lipid content

lymphoma (drainage is blocked, cant absorb chyle)

lipid rich, leading to milky appearance

lymphatic vessels

HIGH triglycerides and chylomicrons present

LOW triglycerides and NO chylomicrons

lipid carriers, found by electrophoresis

exudate

transudate

1. total cell count
2. RBC/WBC count
3. differential cell count (WBC differential)
4. Identify crystals
5. gram stain
6. cytologic exam for malignant cells

mesothelioma

< 1000 cellsL

> 1000 cells/ uL

bloody taps or hemorrhage or disease

RBCs decrease later in collection, small clots may form

blood homogenously distributed; no clotting

cytospin fluid to concentrate cells

most exudates of pleural/peritoneal fluid

A. pleural effusions from TB, neoplasms, and systemic diseases (LE & RA)
B. peritoneal transudates and exudates caused by decreased lymphatic absorption

monocytes, macrophages, eosinophils, plasma cells, LE cells, malignant cells, and mesothelial cells

assist in differentiating fluid as transudate/exudate which aids in establishing cause of fluid accumulation

total protein, pH, LD, CEA, glucose, lipids, amylase

< 0.5 transudate
> 0.5 exudate

< 0.6 transudate
> 0.6 exudate

when glucose is low (variety of diseases)

when it is high in pleural or peritoneal fluid

pancreatitis, esophageal rupture, gastric duodenal perforation, metastatic disease

to identify chylous effusions

pleural exudates caused by pneumonia or lung abscess
<7.30 on antibiotics mean more aggressive treatment is needed

a tumor market

gram stain, acid-fast stain, bacterial cultures, and other stains