ANALYSIS OF URINE AND BODY
FLUIDS
SEROUS
FLUID
Presented by
Agullo, Galenzoga, Tabudlong, Viñas
Serous Fluid
fluid between parietal and visceral membranes
function: to provide lubrication between the two membranes as the surfaces move
against each other
Effusion
accumulation of fluid between the membranes
classified as exudate or transudate
Transudate
disruption of fluid production and regulation between membranes
changes in hydrostatic and oncotic pressure
examples: Hypoproteinemia, Congestive heart failure, Nephrotic syndrome
Exudate
direct damage to the membrane of a particular cavity
examples: Infection, Inflammation, Malignancy
Method of Collection
3 Ps (Pleural, Pericardial, Peritoneal Fluid)
NORMAL APPEARANCE = clear, pale yellow
Pleural fluid = Thoracentesis
Pericardial fluid = Pericardiocentesis
Peritoneal (ascitic) fluid = Paracentesis
SPECIMEN IS DISTRIBUTED IN THE
FOLLOWING TUBES
EDTA = cell caounts and differential
Sterile heparin tubes or SPS = Microbiology and Cytology
Plain/heparin tubes = Chemistry (specimen for pH must be
maintained anearobically on ice)
PLEURAL FLUID
Pleural Fluid
obtained from the pleural cavity, located between parietal membrane lining
the chest wall and visceral pleural membrane covering the lungs.
pleural effusions may be either transudative or exudative.
In addition to the test routinely performed to differentiate between
transudates and exudates, two more are procedures helpful when analyzing
pleural fluid: serum cholesterol and the ratio of pleural fluid: serum total
bilirubin.
A pleural fluid cholesterol >60 mg/dL or a pleural fluid: serum cholesterol
ratio >0.3 provides reliable information that the fluid is an exudate.
A fluid serum total bilirubin ratio of 0.6 or more also indicates the presence of
an exudate.
Measurement of glucose is recommended only in effusion suspected of being
due to rheumatoid arthritis.
APPEARANCE
APPEARANCE
Normal and transudate pleural fluids are clear and pale yellow.
Usually turbidity is related to the presence of WBCs and indicates
bacterial infection, tuberculosis, or an immunologic disorder, such as
rheumatoid arthritis.
The presence of blood in the pleural fluid can signify a hemothorax
(traumatic injury), membrane damage such as occurs in malignancy, or a
traumatic aspiration. As seen with other fluids, blood from a traumatic tap
appears streaked and uneven.
If the blood is from a hemothorax, the fluid hematocrit is more than 50%
of the whole blood hematocrit because the effusion comes from the
inpouring of blood from the injury.
An effusion from a chronic membrane disease contains both blood and
increased pleural fluid, resulting in a much lower hematocrit.
APPEARANCE
The appearance of a milky pleural fluid may be due to the
presence of chylous material from thoracic duct leakage
or to pseudochylous material produced in chronic
inflammatory conditions.
Chylous material contains a high concentration of
triglycerides, whereas
Pseudochylous material has a higher concentration of
cholesterol.
APPEARANCE
DIFFERENTIATION BETWEEN CHYLOUS AND PSEUDOCHYLOUS
APPEARANCE
the differential cell count is the most
diagnostically significant hematology test
performed on serous fluids.
primary cells associated with pleural fluid
include:
macrophages
neutrophils
lymphocytes ·
eosinophils
mesothelial cells
plasma cells
malignant cells.
APPEARANCE
Macrophages normally account for 64% to 80%
lymphocytes (18% to 30%) and neutrophils (1% to 2%)
an increase in pleural fluid neutrophils indicates a bacterial infection, such as
pneumonia.
neutrophils are increased in effusions resulting from pancreatitis and pulmonary
infarction.
Lymphocytes are noticeably present normally in both transudates and exudates in a
variety of forms, including small, large, and reactive. More prominent nucleoli and
cleaved nuclei may be present.
Elevated lymphocyte counts are seen in
effusions resulting from tuberculosis,
viral infections, malignancy, and
autoimmune disorders, such as
rheumatoid arthritis and systemic lupus
erythematosus.
APPEARANCE
Increased eosinophil levels (>10%) may be associated with trauma resulting in
the presence of air or blood (pneumothorax and hemothorax) in the pleural
cavity.
Mesothelial cells are pleomorphic; they resemble lymphocytes, plasma cells, and
malignant cells, frequently making identification difficult.
They often appear as single small or large round cells with abundant blue
cytoplasm and round nuclei with uniform dark purple cytoplasm and may be
referred to as “normal” mesothelial cells.
APPEARANCE
“reactive” mesothelial cells may appear in clusters; have varying
amounts of cytoplasm, eccentric nuclei, and prominent nucleoli; and
be multinucleated, thus more closely resembling malignant cells.
APPEARANCE
the noticeable lack of mesothelial cells associated with
tuberculosis, which results from exudate covering the
pleural membranes. Also associated with tuberculosis
is an increase in the presence of pleural fluid plasma
cells
APPEARANCE
Distinguishing characteristics of malignant cells may include nuclear and
cytoplasmic irregularities, hyperchromatic nucleoli, cellular clumps with
cytoplasmic molding (community borders), and abnormal nucleus: cytoplasm
ratios
APPEARANCE
Malignant pleural effusions most frequently contain large, irregular
adenocarcinoma cells, small or oat cell carcinoma cells resembling
large lymphocytes, and clumps of metastatic breast carcinoma cells
APPEARANCE
Special staining techniques and flow cytometry may be used for positive
identification of tumor cells
CHEMISTRY TEST
the most common chemical tests performed on pleural fluid
are glucose, pH, adenosine deaminase (ADA), and amylase
CHEMISTRY TEST
Triglyceride levels also may be measured to confirm the
presence of a chylous effusion.
Decreased glucose levels are seen with cases of tuberculosis,
rheumatoid inflammation, malignant effusion, esophageal
rupture, lupus pleuritis, and purulent infections.
pleural fluid glucose levels parallel plasma levels, and values
less than 60 mg/dL are considered decreased.
Pleural fluid lactate levels are elevated in bacterial infections
and can be considered in addition to the glucose level.
Pleural fluid pH lower than 7.3 may indicate the need for chest-
tube drainage in addition to administration of antibiotics in
cases of pneumonia.
CHEMISTRY TEST
In cases of acidosis, the pleural fluid pH should be compared with
the blood pH. Pleural fluid pH at least 0.30 degrees lower than the
blood pH is considered significant.
A pH value as low as 6.0 indicates an esophageal rupture that is
allowing the influx of gastric fluid. Collection of specimens for pH
should be taken and analyzed in a manner identical to that for
arterial blood gas specimens.
ADA levels higher than 40 U/L are highly indicative of tuberculosis.
As with serum, elevated amylase levels are associated with
pancreatitis, and often amylase is elevated first in the pleural fluid.
Pleural fluid amylase, including salivary amylase, also may be
elevated in cases of esophageal rupture and malignancy.
MICROBIOLOGICAL AND
SEROLOGICAL TEST
Microorganisms primarily associated with pleural effusions include:
Staphylococcus aureus
Enterobacteriaceae
Anaerobes
Mycobacterium tuberculosis.
Gram stains, cultures (both aerobic and anaerobic), acid-fast stains, and
mycobacteria cultures are performed on pleural fluid when clinically indicated.
Serological testing of pleural fluid is used to differentiate effusions of immunologic
origin from noninflammatory processes. Tests for antinuclear antibody (ANA) and
rheumatoid factor (RF) are performed most frequently.
Detection of the tumor markers carcinoembryonic antigen (CEA), CA 125
(metastatic uterine cancer), CA 15.3 and CA 549 (breast cancer), and CYFRA 21-1
(lung cancer) provide valuable diagnostic information in effusions of malignant
origin.
Pericardial
Fluid
Pericardial
Fluid
Only a small amount (10 to 50 mL) of fluid is found between the
pericardial serous membranes.
Pericardial effusions are primarily the result of changes in the
membrane permeability due to infection (pericarditis),
malignancy, and trauma-producing exudates.
Metabolic disorders, such as uremia or hypothyroidism, as well
as autoimmune disorders.
Appearance
Normal and transudate pericardial fluid appear clear and pale
yellow.
Effusions resulting from infection and malignancy are turbid,
and malignant effusions are frequently blood streaked.
Grossly bloody effusions are associated with accidental
cardiac puncture and misuse of anticoagulant medications.
Milky fluids representing chylous and pseudochylous effusions
also may be present.
Laboratory test
Tests performed on pericardial fluid are directed primarily at
determining whether the fluid is a transudate or an exudate
and includes the ratios for fluid:serum protein and lactic
dehydrogenase (LD).
Example: pleural fluid, WBC counts are of little clinical value,
although a count of >1000 WBCs/µL with a high percentage of
neutrophils can indicate bacterial endocarditis.
Cytological examination of pericardial exudates for the
presence of malignant cells is an important part of the fluid
analysis.
Laboratory test
Cells encountered most frequently are the result of metastatic lung or
breast carcinoma and resemble those found in pleural fluid.
Bacterial cultures and Gram stains are performed on concentrated
fluids when endocarditis is suspected. Frequently infections are
caused by previous respiratory infections, including Streptococcus,
Staphylococcus, adenovirus, and coxsackievirus. Effusions of
tubercular origin are increasing as a result of AIDS.
Acid-fast stains and chemical tests for adenosine deaminase are
requested often on pericardial effusions.
Molecular analysis using PCR is a more sensitive technique for
diagnosing infections caused by organisms that are viral, bacterial, or
fungal.
Table 13-6 summarizes the significance
of pericardial fluid testing
Figure 13-16 shows a metastatic giant
mesothelioma cell that is seen frequently
in pleural fluid and
is associated with asbestos contact.
Marker levels for a pericardial fluid tumor
correlate well with cytological studies
Peritoneal
Fluid
Accumulation of fluid between the peritoneal membranes is
called ASCITES, and the fluid is referred to commonly as
ASCITIC FLUID rather than peritoneal fluid
Peritoneal Lavage is a diagnostic procedure used to detect
Peritoneal
intra-abdominal bleeding in blunt trauma cases, and results of
the RBC count can be used along with radiographic
Fluid procedures to aid in determining the need for surgery.
RBC counts greater than 1000,000/ul are indicative of blunt
trauma injuries. however, this test has been largely replaced by
focused assessment with sonography for trauma (FAST) and
computed tomography (CT) with comparable sensitivity and
superior specificity.
Transudates vs Exudates
The serum-ascites albumin gradient (SAAG) is recommended over the
fluid: serum total protein and LD ratios to detect transudates of hepatic
origin.
Example
Appearance
Like pleural and pericardial fluids, normal peritoneal fluid is clear and pale yellow.
Exudates are turbid with bacterial or fungal infections. Green or dark-brown color indicates
the presence of bile, which can be confirmed using standard chemical tests for bilirubin.
Blood-streaked fluid is seen after trauma and with cases of tuberculosis, intestinal disorders,
and malignancy.
Chylous or pseudochylous material may be present with cases of trauma or blockage of
lymphatic vessels.
Laboratory Tests
Normal WBC counts are less than 500 cells/ul, and the count increases with bacterial
peritonitis and cirrhosis. To distinguish between those two conditions, an absolute neutrophil
count should be performed. An absolute neutrophil count >250 cells/ul or >50% of the total
WBC count indicates infection. Lymphocytes are the predominant cell in tuberculosis and
peritoneal carcinomatosis
Cellular Examination
Examination of ascitic exudates for the presence of malignant cells is
important for detecting tumors of primary and metastatic origin.
Chemical Testing
Chemical examination of ascitic fluid consists primarily of glucose, amylase, and
alkaline phosphatase determinations. Glucose is decreased below serum levels in
bacterial and tubercular peritonitis and malignancy. Amylase is determined on ascitic
fluid to ascertain cases of pancreatitis, and it may elevated in patients with
gastrointestinal perforations.
Microbiology Tests
Gram stains and bacterial cultures for both aerobes and anaerobes are
performed when bacterial peritonitis is suspected.
Acid fast stains, adenosine deaminase, and cultures for tuberculosis may also
be requested
Molecular testing using PCR is a more sensitive and specific methos for the
diagnosis of bacterial infections, including M. tuberculosis.
Serological Tests
Measurement of the tumor markers CEA and CA 125 is a valuable procedure for
identifying the primary source of tumors producing ascitic exudates. The presence of
CA 125 antigen with a negative CEA suggests the source is from the ovaries, fallopian
tubes, or endometrium.
Thank
you!
