Sample Collection Flashcards
What is centesis?
Placing a needle within a body cavity or organ to collect fluid
Who can perform a centesis?
VS only
Where is CSF found?
In the subarachnoid space between the arachnoid and pia mater.
What does CSF usually look like?
Clear, colourless and slightly viscous
Why might a VS examine CSF?
To look for meningitis, neurological conditions +/- tumours
What must be carried out before CSF
Skin prep and clip, sterile gloves and equipment!!
What is synovial fluid?
Found in joints
What is the name for collection of synovial fluid?
Arthrocentesis
Describe the process of arthrocentesis
18-23G needle placed into the joint cavity aseptically! (area previously scrubbed).
Does a patient need GA for arthrocentesis?
May not be required dependant on temperament of patient and Joint being sampled - use LA
What does a normal synovial fluid sample look like?
Straw yellow/clear
Why are joint taps taken?
For diagnosis of conditions such as septic arthritis
What is the name for collecting fluid from the abdomen?
Abdominocentesis
Describe the method of an abdominocentesis?
14-16G 1-2’’ needle or 14-16G butterfly catheter used.
Animal is usually standing and the needle is inserting through the ventral abdomen.
Samples are collected in a plain or EDTA tube
In a normal animal there shouldn’t be any fluid in the abdomen. What would cause there to be?
Infection
Peritonitis
Cardiac, hepatic or renal disease
Neoplasia
What is the name give to the sampling of the thoracic fluid?
Thoracentesis
Why would you sample fluid from thorax?
To check for pyothorax, haemothorax or chylothorax
What are airway washes used for?
Tracheal wash used in horses to diagnose respiratory disease
Describe the method of an airway wash
Endoscope placed down the trachea and saline is flushed down the port.
Fluid is drawn back up using a syringe
The specimen sample is then tested
What is cytology?
The study of the anatomy, physiology, pathology and chemistry of the cell.
What is histology?
Microscopic structure examination of tissues
Why are samples ‘fixed’?
To prevent post-mortem changes, necrosis
What are the 4 liquids used for fixing?
- Formalin = formaldehyde gas dissolved in water (40%)
- 10% Formal Saline = formalin diluted in saline to make a 10% solution
- Neutral Buffered Formalin
- Formalin diluted in buffered saline to make a 10% solution ( the buffer stops pH changes affecting the cells) - Alcohol
- may cause the tissue to shrink and harden
