Fluid Analysis:- Part 1 – Pleural, Pericardial, and ascites, Difference of Transudate and Exudate
Definition of Fluids in various cavities of the body:
- The fluid is secreted by the serous membranes lining the peritoneum, pleural and pericardial cavities.
- Literally, serous fluid means resembling serum.
- This serous fluid is found in the pleural, peritoneal, and pericardial cavities, which will lubricate the opposing parietal and visceral membrane surfaces.
- Inflammation or infection affecting the cavities causes fluid to accumulate.
- Serous fluid is the ultrafiltrate of the plasma.
- The fluid formation depends upon the following:
- Hydrostatic pressure.
- Capillaries permeability.
- Colloid osmotic pressure.
- Lymphatic drainage.
Types of body fluid found are:
- The pericardial cavity around the heart contains the fluid, and the aspiration of the pericardial fluid is called pericardiocentesis.
- Peritoneal or ascitic fluid is found in the abdomen. This is the effusion and accumulation of serous fluid in the abdominal cavity. Its aspiration is called paracentesis.
- Pleural cavity fluid was found in the chest. And aspiration is called thoracentesis.
- Gastric fluid is 1000 to 3000 mL/day.
- Bile is 300 to 1000 mL/day.
- Saliva is 500 to 1500 mL/day.
- Pancreatic fluid is 1000 to 1500 mL/day.
- Small intestinal fluid is 1000 to 2000 mL/day.
- Urine output is 500 to 1500 mL/day.
- Insensible loss through skin and lungs is 600 to 1000 mL/day.
Various body fluids and their quantities:
|Fluid site||Quantity Produced|
|Saliva||500 to 1500 ml/day|
|Gastric fluid||1000 to 3000 mL/day|
|Pancreatic fluid||1000 to 1500 mL/day|
|Small intestinal fluid||1000 to 2000 mL/day|
|Bile||300 to 1000 mL/day|
|Urine output||500 to 1500 mL/day|
|Loss from the skin and lungs||600 to 1000 mL/day|
|Synovial fluid||Minimal amount, Knee Joint <29 mL|
|Cerebrospinal fluid||Total volume = 90 to 200 mL|
|Ascitic fluid, pericardial, and pleural fluids||These are always an abnormal collection|
Normal findings of serous fluids:
Ascitic fluid normal findings:
|Presence of cells||
Characteristic features of Transudate:
Mechanism of transudate formation:
- It is the fluid that accumulates as ultrafiltrate and is called Transudate.
- The capillary pore can allow the passing of the protein of mol. Weight of 200,000 to 300,000 daltons.
- The larger molecular weight proteins are held back and can not cross the basement membranes.
- Transudate accumulates because of the increased hydrostatic pressure in the capillaries.
- The fluid is low in protein as compared to plasma.
Features of Transudate:
|White blood cells||Negative|
Characteristic features of Exudate:
Mechanism of exudate formation:
- Fluid accumulates because of the injury to the membranes due to infection or inflammation.
- The damaged membranes allow passing through the larger molecules of proteins.
Features of Exudate:
|White blood cells||Increased in number|
|Glucose||It is decreased|
|LDH||It is increased|
Types of exudates are:
Difference between Transudate and Exudate:
|Protein||<3 g/dL||>3 g/dL|
|Fluid protein: serum protein ratio||<0.5||>0.5|
|Fluid LD: LD ratio||<0.6||>0.6|
|Specific gravity||<1.016 (<1.015)||>1.016 (>1.015)|
|LDH||Normal <200 IU/L||Increased >200 IU/L|
|Glucose||Normal (equal to serum level)||<than or equal to serum|
|Pleural fluid cholesterol||<60 mg/dL||>60 mg/dL|
|Pleural fluid: serum cholesterol ratio||<0.3||>0.3|
|Pleural fluid: bilirubin ratio||<0.6||>0.6|
|Fibrinogen||No clot||Clots are seen|
|Spontaneous clotting||Negative||May see clot formation|
|Cell count||300 to 1000 /cmm||>1000 /cmm|
Questions and answers:
Question 1: What is protein level in transudate?
Protein in the transudates is <3 g/dL
Question 2: What is the cell count in the exudate?
Cell count in the exudate is >1000/cmm.