Sampling Methods

Question 1

examples of diagnostic sampling methods?

Answer 1

FNA
Biopsies
Joint and CSF taps
Thoracocentesis
Pericardiocentesis
Abdominocentesis
BAL

Question 2

What equipment do you need for an FNA?

Answer 2

Gloves
Needles
Slides
Slide container
Pencil
Lab form

Question 3

where do you normally perform an FNA?

Answer 3

Lymph nodes
Small masses
Internal organs

Question 4

what can you diagnose with an FNA?

Answer 4

checks sites for Inflammation and neoplasia

Question 5

what are the advantages of an FNA?

Answer 5

Diagnostics

Minimally invasive

Can be done without sedation/GA in most cases

Question 6

what are the disadvantages of an FNA?

Answer 6

Haemorrhage - low risk

Introducing infection - low risk

Organ perforation - if internal organs

Introduction of air - lung FNA

Question 7

what is the difference between fenestration and aspiration?

Answer 7

two types of FNA techqniues

Fenestration
- uses only a small needle
- good for small areas (eg small masses)
- less blood contamination as no neg pressure from syringe
- less cellular damage as no neg. pressure from syringe
- can’t do on organs as syringe stops air from entering the cavity

Aspiration
- provides negative pressure
- good for firm masses that havent worked with fenetration
- good for painful and sensitive areas
- only need to enter site once

Question 8

what stains are used on an FNA sample?

Answer 8

inhouse = diff-quick

external = wright stain

Question 9

what is the difference between a biopsy and an FNA?

Answer 9

FNA
- little to no sedation
- non-specific cytology
- results often non-diagnostic

biopsy
- easier to visualise on US
- can do laparoscopic or surgical biopsies
- a diagnosis is quarenteed
- high complications - haemorrhage
- requires sedation/GA - so fasting
- small needles can cause tissue crushing and fragmentation

Question 10

what equipment do you need for a biopsy?

Answer 10

Sterile Gloves
Biopsy needle
Formalin pot
Slides
Slide container
Pen
Lab form

Question 11

where do you normally perform a biopsy?

Answer 11

Internal organs

Commonly done during surgery

Question 12

what can you diagnose with a biopsy?

Answer 12

Inflammation
Infection
Neoplasia

Question 13

what are the disadvantages of a biopsy?

Answer 13

Painful
- requires sedation or GA

High risk of haemorrhage
- coagulation testing is vital prior to liver/spleen biopsy

Risk of pneumothorax if lung

Damage to other organs

Vagal response (cats)

Hypertensive crisis – adrenal gland

Question 14

what equipment do you need for a thoracocentesis?

Answer 14

gloves
clippers
chloroprep
lidocaine
blade
butterfly needle
syringe
3-way-tap/one way valve
kidney dish
EDTA tube

Question 15

what is the site of insertion for a thoracocentesis?

Answer 15

7th-9th intercostal space

avoids liver and heart

Question 16

what do different samples from a thoracocentesis suggest?

Answer 16

blood = haemothorax
- neoplastic effusion
- run PCV

puss = pyothorax
- bacterial infection in chest cavity
- run cytology

air = pneumothorax
- lung rupture

pale liquid = chylothorax
- lymph fluid
- thoracic duct damaged
- run biochem

neoplastic
- run cytology

Question 17

what are the advantages of a thoracocentesis?

Answer 17

Diagnosis

Therapeutic
- removes fluid or air from lungs
- improves inflation and ventilation

Question 18

what are the possible complications of a thoracocentesis?

Answer 18

Can require sedation/GA
- depending on patient compliance

Risk of haemorrhage and pneumothorax

Must be monitored closely after procedure

Question 19

what equipment do you need for a pericardiocentesis?

Answer 19

gloves
clippers
chloroprep
lidocaine
blade
periocardiococentesis catheter
syringe
3-way-tap/one way valve
kidney dish
EDTA tube

Question 20

what is the site of insertion for a pericardiocentesis?

Answer 20

3rd-5th intercostal space

ideally right lateral

Question 21

what can a pericardiocentesis let us diagnose?

Answer 21

often neoplasia

run cytology to confirm

Question 22

whatchecks should you perform during a pericardiocentesis?

Answer 22

ensure patient is on an ECG
- hit heart = arythmias

check small sample for clotting before draining
- confirms not blood from heart

Question 23

what are the possible complications of a pericardiocentesis?

Answer 23

Painful

Requires sedation/GA in most cases

Hgh risk of hitting major vessels/perforating ventricle

Haemorrhage

Arrythmias

Pneumothorax

Effusion is very likely

Question 24

what are the advantages of a pericardiocentesis?

Answer 24

Diagnosis

Therapeutic
- remove fluid from cardiac space
- stop/prevent cardiac tamponade - pressure preventing filling of right ventricle

Question 25

what equipment is needed for a joint tap?

Answer 25

sterile gloves
clippers
chloroprep
needle
syringe
slides
EDTA and serum tubes

Question 26

best technique for a joint tap?

Answer 26

Flex joint to open joint capsule

Question 27

what can a joint tap help us diagnose?

Answer 27

collection of synovial fluid
- smear and cytology
- EDTA for WBC count
- heparin for clot testing
- blood culture

also helps differentiate:
- inflammatory or infectious
- traumatic, acute or chronic

Question 28

crude assessment of synovial fluid?
what can it tell us?

Answer 28

colour
- normally clear
- yellow = bleeding (bilirubin)

clarity/apacity
- normally clear
- more opaque = inflammation

viscosity
- normally quite thick
- if thinned then infection/inflammation

Question 29

what are the disadvantages of a joint tap?

Answer 29

high risk of intoducing infection
some risk of haemmorrhage

requires sedation/GA

Question 30

what equipment do you need for a cerebrospinal fluid tap?

Answer 30

clippers
chloroprep
sterile gloves
spinal needle
- no syringe as neg pressure causes damage
EDTA tube

Question 31

where can you perform a CSF tap?

Answer 31

cisternal - preferred
lumbar

Question 32

what can you diagnose with a CFS tap?

Answer 32

should be colourless, ordorless and clear
- if not then issue

cytology - check bacteria/inflammatory cells

protein assessment

fungal culture - check toxoplasma/nesopora

Question 33

what are the disadvantages of CSF taps?

Answer 33

Possible trauma to the spinal cord

Introduction of infection

Raises intracranial pressure
- brain herniation
- avoid cisternal if patients already have raised pressure

Must be under GA

Question 34

what equipment do you need for an abdominocentesis?

Answer 34

gloves
clippers
chloroprep
butterfly needle
slides
if drain then 3-way tap
EDTA tube

Question 35

reasons for ascites?

Answer 35

heart failure
uroabdomen - trauma
splenic or GI rupture/trauma
- haemoabdomen
low protein = low albumin
FIP
infection

Question 36

where do you perform an abdominocentesis?

Answer 36

centre of linea alba

use ultrasound to guide into fluid pockets

Question 37

what can an abdominocentesis allow us to diagnose?

Answer 37

neoplasia
haemorrhage
FIP (yellow and straw-like)

cytology
- bacteria/infection
biochemistry
- hypoalbuminaemia or urine

Question 38

what are the advantages of an abdominocentesis?

Answer 38

diagnosis

therapeutic
- reduces abdominal pressure
- improve ventilation
- reduce pressure on organs

Question 39

what are the disadvantages of an abdominocentesisis?

Answer 39

risk of perforating internal organs

risk of haemorrhage

sedation likely needed

Question 40

what equipment do you need for a broncho-alveolar lavage?

Answer 40

Intubation equipment

EDTA
Serum tubes
Gloves
Syringe
Saline
Endoscope

Question 41

where do you perform a BAL?

Answer 41

down ET tube

Question 42

what can a BAL allow us to diagnose?

Answer 42

Pneumonia
Lungworm
Asthma

Question 43

what are the disadvantages of a BAL?

Answer 43

risk of hypoxia
- monitoring spO2 is vital

bronchospasm post proedure common
- especially in cats

may worsen respiratory signs
- due to inflammation