Chapter 16 Serous Fluid Professor A. S. Alhomida King Saud University College of Science Department of Biochemistry Disclaimer The texts, tables and images contained in this course presentation (BCH 376) are not my own, they can be found on: References supplied Atlases or The web Chapter 16 Serous Fluid Professor A. S. Alhomida

Closed Cavities of the Body Pleural Cavity Pericardial Cavity Peritoneal Cavity

Closed Cavities of the Body, Cont’d They are lined by two membranes referred to as the serous membranes. One membrane lines the cavity wall (parietal membrane, and the other covers the organs within the cavity (visceral membrane) Fluid between the membranes is called serous fluid

Function of Serous Fluid Provide lubrication as the surfaces move against each other Normally, only small amount of serous fluid is present, because production and reabsorption take place at a constant rate

Formation of Serous Fluid It is formed as ultrafiltrates of plasma, with no additional material contributed by the membrane cells depends on two different pressures: Hydrostatic pressure Colloid pressure

Formation of Pleural Fluid

Formation of Pleural Fluid

Pleural Cavity

Effusion of Serous Fluid It is the disruption of the mechanism of serous fluid formation and reabsroption causes an increase in fluid between the membranes

Effusion of Serous Fluid, Cont’d Causes: Increased Hydrostatic Pressure Congestive heart failure pressure Decreased Colloid Pressure Hypoproteinemia Increased capillary permeability (inflammation and infection) Lymphatic obstruction (tumors)

Collection of Serous Fluid Fluid is collected by needle aspiration (100 mL) from the respective cavities Thoracentesis for pleural cavity Pericardiocentesis for pericardial cavity Paracentesis for peritoneal cavity

Thoracentesis

Pericardiocentesis

Paracentesis

Classification of Effusion Transudates Causes They produced because of a systemic disorder that disrupts the balance in the regulation of fluid filtration and reabsorption as the change in hydrostatic pressure created by congestive heart failure or the hypoproteinemia associated with the nephrotic syndrome

Classification of Effusion, Cont’d Exudates Causes They are produced by conditions that directly involve the membranes of the particular cavity, including infections and malignancies

Transudated and Exudates

Transudated and Exudates

Pleural Fluid It is obtained from the pleural cavity, located between the parietal pleural membrane lining the chest wall and visceral pleural membrane covering the lungs Pleural effusions can be transudative or exudative origin

Pleural Fluid, Cont’d Procedures are helpful when analyzing pleural fluid For Exudates, if Pleural Fluid Cholesterol > 60 mg/dL or Pleural Fluid/Serum Cholesterol Ratio > 0.3 Pleural Fluid/Serum Total Bilirunbin Ratio > 0.6

Light's Criteria If at least one of the following three criteria is present, the fluid is virtually always an exudate If none is present, the fluid is virtually always a transudate Pleural fluid protein/serum protein ratio greater than 0.5. Pleural fluid LDH/serum LDH ratio greater than 0.6. Pleural fluid LDH greater than two thirds the upper limits of normal of the serum LDH

Physical Properties of Pleural Fluid

Types of Pleural Effusions

Evaluation of Pleural Fluid

Pleural Fluid Cells

Pleural Fluid Cells, Cont’d

Pleural Fluid Cells, Cont’d

Pleural Cells, Cont’d

Pleural Cells, Cont’d

Pleural Cells, Cont’d

Pleural Cells, Cont’d

Pleural Cells, Cont’d

Biochemical Testing of Pleural Fluid

Pericardial Fluid Normally, only a small amount (10-50 mL) of fluid is found between the pericardial serous membranes Pericardial effusions are result primarily of changes in the permeability of the membranes due to infection (pericarditis), malignancy, trauma, or metabolic disorders as uremia

Pericardial Fluid, Cont’d Presence of pericardial effusion is expected when cardiac compression is noted during the physician’s examination

Pericardial Cavity

Physical Properties of Pericardial Fluid

Pericardial Fluid Cells

Peritoneal Cavity

Peritoneal Dialysis

Peritoneal Fluid Accumulations of fluid in the peritoneal fluid cavity is called ascites, and the fluid is commonly referred to as ascitic fluid rather than peritoneal fluid Hepatic disorder, such as cirrhosis, are frequent causes ascitic transudative fluids Bacterial infections (peritonitis) are most frequent causes of ascitic exudative fluids

Ascitic Transudates vs Exudates Differentiation between ascitic fluid transudates and exudates is more difficult that for pleural and pericardial effusions Serum/ascites albumin gradient is recommended over the fluid/serum total protein and LDH ratios for detection for the transudates of hepatic origin

Ascitic Transudates vs Exudates, Cont’d A difference (gradient) of 1.1 or greater suggests a transudates effusion of hepatic origin, and lower gradients are associated with exudative effusions

Ascitic Transudates vs Exudates, Cont’d Example: Serum albumin = 3.8 mg/dL Fluid albumin = 1.2 mg/dL Gradient 3.8 – 1.2 = 2.6 then indicating hepatic effusion

Physical Properties of Ascitic Fluid

Peritoneal Fluid Cells

Peritoneal Fluid Cells

Peritoneal Fluid Cells

THE END Any questions?