Effusions Flashcards
What is an effusion?
Increased amount of fluid in the abdominal or thoracic cavity
What are the three reasons for analysis of effusions?
Differentiate between different fluid types
- Allow further diagnostic procedures
Identify fluid types with a more specific etiology
Definitive diagnosis
Describe fluid collection for counts, cytology and protein
Collect into EDTA so fluid won’t clot
Which tubes should be used for biochemical tests or culture with fluid analysis?
Serum (plain) tubes
Describe the normal fluid in small animals
Low volume
Clear, straw colour
Total protein: 25-30 g/l
Nucleated cell count <3 x10e9/l
Cells:
- Mesothelial cells
- Macrophages
What four factors affect movement of fluid in and out of the pleural/peritoneal cavities?
Hydrostatic pressure
Colloid osmotic pressure (albumin)
Permeability of the capillary wall
Lymphatic drainage
What are the three classifications of effusion based on cell counts and total protein?
Transudate
Modified transudate
Exudate
Describe transudate fluid
Low protein and low cellularity
Clear
Specific gravity < 1.018
Total protein <25g/l
TNCC <0.5x10e9/l
Cells:
- Mesothelial cells
- Macrophages
- Low numbers non-degenerate neutrophils
What are some causes of transudate fluid?
Decreased colloid osmotic pressure
Hypoalbuminemia second to:
- Glomerular disease
- Hepatic disease
- GI loss
What levels will hypoalbuminemia cause transudate?
<10g/l
Describe how hepatic cirrhosis and portal hypertension cause transudate formation
Secondary from hepatic fibrosis/cirrhosis
Prolonged portal hypertension and formation of secondary collateral circulation
Local production of vasodilators
Leads to splanchnic vasodilation and decreased effective blood flow
Compounded by renal retention of sodium via renin/angiotension system and generalized hypertension
End result causes expansion of plasma volume and leakage of low protein lymph from the intestines
Describe modified transudate
Yellow to serosanguinous
Cloudy
TNCC 0.3-5.5x10e9/l
S.G. 1.018-1.030
Protein variable 25-50 g/l
Cells:
- Mesothelial cells
- Macrophages
- Non-degenerate neutrophils
- Small lymphocytes
What are the causes of modified transudates?
Cardiac disease:
- Congestion
- Leakage of protein rich lymph from the liver
- Sodium and fluid retention
Chylous effusion
Lymphatic obstruction
Describe exudate
Turbid - red, yellow or white
High TNCC and protein
S.G. >1.018
Total protein > 30g/l
TNCC > 3.0x10e9/l
Cells:
- Neutrophils
- Macrophages
What are the causes of exudate?
Inflammation of pleural/abdominal cavities
Inflammation of pleural/abdominal cavity lining
Long standing modified transudate
Neoplasia
What is seen in a non-septic exudate?
Non-degenerate neutrophils
No bacteria
What is seen in septic exudate?
Degenerate neutrophils
Intracellular bacteria
Describe the appearance of haemorrhage
Turbid - red
S.G. 1.025-1.040
Total protein > 30g/l
TNCC 1.5-10x10e9/l
Cells:
- WBC from peripheral blood
- Macrophages
What are the three types of haemorrhage and what can cause them?
Iatrogenic or ongoing:
- Erythrocytes
- Platelet clumps
Acute:
- Erythrophagia
Chronic:
- Siderophages
- Haematoidin
Describe chylous effusion
Opaque, milky
S.G. > 1.017
Variable protein
TNCC 1.5-20x10e9/l
Acute:
- Small lympocytes
- Mature macrophages
- Variable neutrophils
Chronic:
- Mixed population
- Increased neutrophils
What occurs with cylous effusions if refrigerated?
Formation of cream top
What is the difference between triglyceride levels in serum and fluid? Cholesterol?
Triglycerides higher in fluid
Cholesterol lower in fluid
What are mesothelial cells?
Normal lining cells of the abdominal and thoracic cavities
What do mesothelial cells show with inflammation or effusions?
Reactive change
What are the three ectopic sources of fluid?
Urine - uroabdomen
- Transudate
- Modified transudate
Bile - bile peritonitis
- Green colour
- Modified transudate
- Exudate
Pancreatitis
- Modified transudate
- Exudate
How do biochemistry ratios differ between fluids and plasma?
Usually greater in fluid than in plasma
How much peritoneal fluid could be collected from a normal horse?
3-5ml
Describe normal equine peritoneal fluid
Pale yellow or clear
TNCC 0.5-9x10e9/l
Protein < 15g/l
Specific gravity 1.000-1.010
Cells:
- 50% macrophages
- 50% non-degenerate neutrophils
What does non-septic exudate of equine peritoneal fluid look like?
Amber slightly turbid fluid
TNCC > 10x10e9/l
Protein > 25g/l
Cells:
- More neutrophils than macrophages
Describe septic exudate in horses
Yellow, brown turbid fluid
TNCC > 10x10e9/l
Protein > 34g/l
Cells:
- Degenerate neutrophils
- Bacteria
- Can have plant material
How can you tell the difference between tapping into the gut or peracute rupture in horses?
Both have:
- Plant material
- Bacteria
- Possibly protozoa
Cell count will be low with peracture rupture
Gut rupture will quickly develop cardiac collapse
