Lecture 15 10/29/24

Question 1

What is oncotic pressure?

Answer 1

water following solids

Question 2

What is hydraulic pressure?

Answer 2

force of flow when fluid encounters resistance

Question 3

Which system in the body drains fluid from body cavities?

Answer 3

lymphatic system

Question 4

What are the characteristics of fluid formed by plasma exiting the arterial capillary bed?

Answer 4

-low protein conc.
-low cellularity
-normal fluid in body cavity

Question 5

What is the cycle for normal body cavity fluid?

Answer 5

-fluid moves out of capillaries
-fluid lubricates organs
-fluid is drained by lymphatics
-fluid goes back into the vascular space

Question 6

What is an effusion?

Answer 6

pathological fluid accumulation

Question 7

What are the mechanisms of pathologic fluid accumulation?

Answer 7

-disturbances in fluid circulation
-inflammation in a body cavity
-organ rupture
-neoplasia

Question 8

What is the clinical presentation of abdominal/peritoneal effusions?

Answer 8

-distended abdomen
-exercise intolerance
-possible respiratory difficulty

Question 9

What is the clinical presentation of thoracic/pleural effusions?

Answer 9

-increased resp. rate
-difficulty breathing
-exercise intolerance/weakness

Question 10

What is the clinical presentation of pericardial effusions?

Answer 10

-exercise intolerance/weakness/collapse
-respiratory difficulty
-muffled heart sounds
-weak pulses
-jugular distension
-ECG abnormalities
-abdominal effusion possible

Question 11

What is a purple top tube/EDTA tube used for when collecting effusion samples?

Answer 11

-total protein
-total nucleated cell count
-cytology

Question 12

What is a green top tube/heparin tube used for when collecting effusion samples?

Answer 12

-K+
-creatinine
-bilirubin
-triglycerides
-glucose
-lactate

Question 13

What is a red top tube/non-additive tube used for when collecting effusion samples?

Answer 13

bacterial culture and susceptibility

Question 14

How should smear samples be shipped?

Answer 14

-should include direct smear of fresh fluid +/- stained smear
-slide shipped in room temp. slide holder

Question 15

How should tube samples be shipped?

Answer 15

-refrigerated EDTA tube +/- additional heparin and additive free tubes
-shipped overnight on cool pack

Question 16

How does a fluid analysis differ from a cytology (UTCVM specific)?

Answer 16

-fluid analysis looks at total protein refractometry, total nucleated cell count, and microscopic eval.
-cytology only looks at microscopic eval.

Question 17

What type of effusion is typically seen with disturbances in fluid circulation?

Answer 17

transudate

Question 18

What are the mechanisms of transudate production?

Answer 18

-decreased oncotic pressure
-increased hydraulic pressure
-altered lymphatic drainage

Question 19

What is a clinical example of decreased oncotic pressure?

Answer 19

protein losing nephropathy

Question 20

What is a clinical example of increased hydraulic pressure?

Answer 20

right-sided heart failure

Question 21

What is a clinical example of lymphatic obstruction?

Answer 21

space-occupying mass

Question 22

What is a transudate?

Answer 22

fluid with low cellularity and variable protein concentration

Question 23

What difference determines if a transudate will have high or low protein?

Answer 23

-transudates that come from vessels with small fenestrations will have low protein
-transudates that come from vessels with large fenestrations will have high protein

Question 24

What is the pathophysiology of exudates?

Answer 24

-sterile or infectious inflammatory stimulus
-inflammation leads to increased vascular permeability
-leaky vessels allows for exudation of fluid, protein, and cells
-chemokines attract inflammatory cells

Question 25

What is an exudate?

Answer 25

fluid with high cellularity and high protein

Question 26

What are the characteristics of a sterile exudate?

Answer 26

-high protein -high cellularity -non-degenerate neutrophils -submitted for bact. culture as a precaution

Question 27

What is sepsis?

Answer 27

systemic inflammation due to bacterial infection

Question 28

What are the two meanings of septic?

Answer 28

-"a patient that has sepsis" -"containing bacteria," but not having the clinical syndrome of sepsis

Question 29

What are the characteristics of a septic effusion?

Answer 29

-high protein -high cellularity -degenerate neutrophils -bacteria phagocytized by neutrophils and/or macrophages -positive bact. culture is gold standard for diagnosis

Question 30

What are the characteristics of glucose as an effusion biochemical marker?

Answer 30

-helps ID septic effusion -fluid glucose is typically less than plasma glucose

Question 31

What are the characteristics of lactate as an effusion biochemical marker?

Answer 31

-helps ID septic effusion or strangulating obstruction -fluid lactate is typically greater than plasma lactate

Question 32

What are the characteristics of a low-protein transudate?

Answer 32

-colorless and clear -total protein less than 2.5 -total nucleated cell count less than 5000 -mononuclear cells predominate

Question 33

What are the characteristics of a high-protein transudate?

Answer 33

-light yellow and clear -total protein greater than 2.5 -total nucleated cell count less than 5000 -mononuclear cells predominate

Question 34

What are the characteristics of an exudate?

Answer 34

-variable color -turbid/cloudy/opaque -total protein greater than 2.5 -total nucleated cell count greater than 5000 -neutrophils predominate

Question 35

What type of effusion is typically seen with inflammation in a body cavity?

Answer 35

exudate

Question 36

Which types of effusion are typically seen with organ rupture?

Answer 36

-exudate -hemorrhage

Question 37

What are the characteristics of effusions due to GI rupture?

Answer 37

-variable appearance -find mixed bacteria and debris -can perform glucose and lactate testing -caused by linear foreign body or necrosis from neoplasia

Question 38

What are the characteristics of uroabdomen?

Answer 38

-variable appearance -looks like a transudate early on -looks like an exudate later on -crystals that are typically found in urine may be seen -can test creatinine and potassium conc.; confirmatory if 2x greater than plasma conc. -caused by urinary tract rupture

Question 39

What are the characteristics of chylous effusion?

Answer 39

-white, milky, lactescent -highly vacuolated light purple background with many small lymphocytes -triglyceride conc. greater than 100mg/dL is confirmatory -caused by lymphatic duct rupture or leakage

Question 40

What are the characteristics of bile peritonitis?

Answer 40

-exudate appearance -presence of bile in background and within macrophages -bilirubin conc. 2x greater than plasma bilirubin is confirmatory -caused by biliary tract rupture

Question 41

What are the characteristics of hemorrhagic effusion?

Answer 41

-grossly bloody -looks like a blood smear, but minus platelets -may see erythrophagocytosis and/or presence of hemosiderin -PCV >3% suggests hemorrhagic component -caused by organ rupture or coagulopathy

Question 42

What are the characteristics of neoplastic effusion?

Answer 42

-variable appearance -will see cells with malignancy features -flow cytometry, PARR, and special stains help to confirm -caused by tumor rupture or exfoliation

Question 43

What are the characteristics of pericardial effusion?

Answer 43

-often hemorrhagic but can appear like a transudate -typically appears like a hemorrhagic effusion +/- mesothelial cells -can be caused by idiopathic pericarditis, neoplastic rupture, or atrial rupture