Pleural, Pericardial, and Peritoneal Fluid Analysis

Vocabulary practice cards covering the anatomy, physiology, collection, classification, and analysis of pleural, pericardial, and peritoneal fluids, including transudate and exudate differentiation.

Parietal membrane

The serous membrane that covers the internal surfaces of the body cavity wall.

Visceral membrane

The serous membrane that covers the lungs, heart, and abdominal organs.

Pleural cavity

The fluid-filled space or cavity between the membranes surrounding the lungs.

Pericardial cavity

The fluid-filled space or cavity between the membranes surrounding the heart.

Peritoneal cavity

The fluid-filled space or cavity between the membranes surrounding the abdominal organs.

Parietal Pleura

The outer serous membrane of the lungs attached to the thoracic wall.

Visceral Pleura

The inner serous membrane covering the surface of the lungs.

Parietal Pericardium

The outer serous membrane layer of the heart cavity.

Epicardium

The visceral pericardium, which is the inner layer covering the heart.

Parietal Peritoneum

The outer serous membrane lining the abdominal cavity wall.

Serosal Mesothelium

The visceral peritoneum, which covers the abdominal organs (visceral membrane).

Dynamic fluid formation

The process of formation and absorption of fluid controlled by capillary permeability, pressures, and the lymphatic system.

Hydrostatic pressure

Blood pressure in the capillaries of the parietal membrane that forces plasma ultrafiltrate to form in the cavity.

Oncotic pressure

Colloid osmotic pressure produced by plasma proteins in capillaries that opposes the filtration of fluid into the cavity.

Capillary permeability

One of the four factors controlling fluid formation and absorption in the parietal membrane.

Lymphatic system absorption

The process by which fluid is removed from body cavities to maintain dynamic balance.

Effusion

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

Paracentesis

A puncture of a body cavity for the aspiration of fluid.

Thoracentesis

A surgical procedure performed to obtain pleural fluid.

Pericardiocentesis

A surgical procedure performed to obtain pericardial fluid.

Peritoneocentesis

A surgical procedure, also known as abdominal paracentesis, to obtain peritoneal fluid.

Ascites

An effusion specifically located in the peritoneal cavity.

Ascitic fluid

The liquid obtained from an effusion in the peritoneal cavity, same as peritoneal fluid.

Sterile tubes with anticoagulant

Collection containers used for microscopic exam or microbiological studies to prevent clotting from fibrinogen or blood.

Red-top tubes

Nonanticoagulant tubes used for chemistry studies of body cavity fluids.

Specimen transport

Fluid specimens should be maintained at room temperature and transported to the lab immediately.

Comparison blood sample

A sample collected alongside cavity fluid for comparison of chemical parameters like protein and LD.

Transudate

A noninflammatory fluid resulting from systemic disease causing increased hydrostatic pressure or decreased plasma oncotic pressure.

Exudate

A fluid resulting from inflammatory processes that increase capillary permeability or decrease lymphatic absorption.

Congestive heart failure

A systemic disease commonly associated with the formation of transudates.

Infections and neoplasms

Common pathological conditions that result in the formation of exudates.

Transudate physical appearance

Clear and pale yellow fluid with a viscosity similar to serum.

Exudate physical appearance

Usually cloudy fluid of various colors that may have a shimmer or sheen.

Clotting in transudates

These fluids do not clot because they lack fibrinogen.

Clotting in exudates

These fluids can form clots spontaneously.

Cloudy paracentesis fluid

Indicates large numbers of white blood cells ($WBCs$), other cells, chyle, and/or lipids.

Milky fluid after centrifugation

An indicator of the presence of chyle in the specimen.

Chylous effusions

Effusions caused by obstruction of or damage to the lymphatic system.

Pseudochylous effusions

Chronic effusions that can be differentiated from chylous ones by having low triglycerides and no chylomicrons.

Chylous lipid content

Characterized by high triglycerides and the presence of chylomicrons.

Pseudochylous lipid content

Characterized by low triglycerides and the absence of chylomicrons.

Microscopic examination components

Includes total cell count, RBC and WBC counts, differential count, crystal identification, Gram stain, and cytologic exam.

Transudate WBC count

$WBC$ counts less than $1000\text{ cells/}\nu\text{L}$ in pleural fluid or less than $300\text{ cells/}\nu\text{L}$ in peritoneal fluid.

Exudate WBC count

$WBC$ counts greater than $1000\text{ cells/}\nu\text{L}$ in pleural fluid or greater than $500\text{ cells/}\nu\text{L}$ in peritoneal fluid.

Traumatic tap

A collection error where $RBCs$ decrease later in collection and small clots may form.

Hemorrhagic effusion

A disease-related accumulation where blood is homogenously distributed and there is no clotting.

Cytocentrifuge slide

The preparation method used for performing a differential cell count on cavity fluids.

Neutrophils in exudates

The predominant cell type in most exudates of pleural and peritoneal fluid.

Lymphocytes in pleural effusions

Predominate in effusions from tuberculosis (TB), neoplasms, and systemic diseases.

Lymphocytes in peritoneal fluid

Predominate in transudates and exudates caused by decreased lymphatic absorption.

Lupus erythematosus (LE) cells

Specific cells that may be identified during a differential cell count of serous fluids.

Mesothelial cells

Cells lining the serous membranes that are commonly found in serous fluid differentials.

Fluid/serum protein ratio: Transudate

Values less than $0.5$ identify the fluid as a transudate.

Fluid/serum protein ratio: Exudate

Values greater than $0.5$ identify the fluid as an exudate.

Fluid/serum LD ratio: Transudate

Values less than $0.6$ identify the fluid as a transudate.

Fluid/serum LD ratio: Exudate

Values greater than $0.6$ identify the fluid as an exudate.

Fluid glucose significance

Only a low fluid glucose level is considered significant and is associated with various disease processes.

Amylase elevation causes

High pleural or peritoneal levels are associated with pancreatitis, esophageal rupture, gastric duodenal perforation, and metastatic disease.

Amylase

A chemical marker used to identify pancreatic or gastrointestinal involvement in effusions.

Lipids analysis

Used to identify chylous effusions by investigating triglyceride and chylomicron levels.

Normal pleural pH

The normal range for pleural fluid is $7.60-7.64$.

Low pleural pH significance

pH levels less than $7.30$ while on antibiotics indicate pneumonia or lung abscess requiring aggressive treatment.

Carcinoembryonic antigen (CEA)

A tumor marker used in the chemical examination of serous fluids.

Microbiological examination

May include Gram stain, acid-fast stain, and bacterial cultures; requires an experienced technologist.

Bilirubin ratio (fluid-to-serum)

$0.6$ is the threshold; transudates are below and exudates are above this value.

Transudate Glucose level

Typically equal to the serum glucose level.

Exudate Glucose level

Typically less than or equal to the serum glucose level.

Total Protein (TP) concentration in transudates

Values are less than $50\%$ of the serum concentration.

Total Protein (TP) concentration in exudates

Values are greater than $50\%$ of the serum concentration.

LD activity in transudates

Values are less than $60\%$ of the serum level.

LD activity in exudates

Values are greater than $60\%$ of the serum level.

Cholesterol ratio (fluid-to-serum): Transudate

A ratio value of less than $0.3$.

Cholesterol ratio (fluid-to-serum): Exudate

A ratio value of greater than $0.3$.

Mononuclear cells in transudates

The predominant cell type in the differential count of transudative fluids.

Early exudate differential

The stage of an inflammatory process where neutrophils predominate in the fluid.

Late exudate differential

The stage of an inflammatory process where mononuclear cells predominate in the fluid.

Metastatic tumor cells

Malignant cells that have spread from a primary site, such as fallopian tube carcinoma, to serous fluids.

Mast cells in peritoneal fluid

Elevated counts of these cells are heavily associated with endometriosis.

Tryptase levels

Higher levels of this marker in peritoneal fluid are associated with endometriosis.

Endometriosis

A condition associated with elevated mast cell counts and higher tryptase levels in peritoneal fluid.

Parietal membrane capillaries

Their permeability is one of the four factors controlling fluid dynamics in serous cavities.

Plasma ultrafiltrate

The fluid formed in the cavity by hydrostatic pressure forcing it out of the capillaries.

Pleural transudate color

Pale yellow.

Pleural exudate color

Variable; can be yellow, greenish, pink, or red.

Pleural transudate clarity

Clear.

Pleural exudate clarity

Cloudy.

Differential: TB effusion

A pleural effusion characterized by a predominance of lymphocytes.

Differential: Neoplasms

Pleural effusions where lymphocytes predominate.

Traumatic tap RBC decrease

The reduction of red blood cells observed in later tubes during collection.

Traumatic tap clots

Small clots that may form due to collection artifacts rather than a disease process.

Pathological processes

Abnormal states indicated by the accumulation of fluid (effusions) in body cavities.

Systemic disease

A disease affecting the whole body that typically results in the formation of transudates.

Decreased oncotic pressure

A cause of transudate formation typically due to a decrease in plasma proteins.

Increased capillary permeability

A primary cause of exudate formation during inflammatory processes.

Decreased lymphatic absorption

A process leading to exudate formation, often seen in chronic effusions.

Cytologic exam

Part of a microscopic exam explicitly looking for malignant cells in the fluid.

Anticoagulant in tubes

Coating used in sterile tubes to prevent clotting in abnormal specimens containing fibrinogen.

Metastatic fallopian tube carcinoma

Specific cancer cited as a source of malignant cells in the lecture notes.

Acid-fast stain

A microbiological stain used during the examination of serous fluids.

Peritoneal transudate mononuclear cells

The cell type that dominates in noninflammatory abdominal effusions.