IV Access Flashcards
Describe an over the needle cannula
- Cannula over needle
- Whole set introduced into blood vessel
- Cannula slid off needle
- Relatively stiff
Describe a through the needle cannula
- Large insertion needle with cannula passed through
- Used in central veins
Describe a Peel away cannula
Place through an over the needle cannula
Describe a seldinger cannula
(Over the wire cannula)
- IV cannula
- Wire passed down cannula and vasodilator administered
- Cannula 1 removed and longer and more flexible cannula replaces it
Describe the chemical, physical and biological properties of cannula material
Chemical - stable on sterilisation and implantation
Biological - Non irritant, non thrombogenic, resists microbial adhesion
Physical - High tensile strenth, flexible but not compressible
Give an example of a material that is good for making cannulas
Silicone elastomes
What effect can the shape and sharpness have on the effect of a cannula on the body
Can play a role in reducing endothelial trauma
Rounded Tips preferable to square /bevel ended
Describe the placement of a cannula in the ceplallic vein
- Runs down the dorsal aspect of the forelimb
- Comes in laterally
- Start distally and can then move to a higher site if unable to cannulate
Describe the placement of a cannula in a saphenious vein
Obvious veins on the caudolateral end of the hind limb - above the hock
- Must be in lateral recumbency (require assistance)
Describe the placement of a cannula in the Jugular vein
Dogs - Straight line from thoracic index to jaw
Horses - within jugular groove
(Use for long term cannulation)
Describe the placement of a cannula in the Auricular vein
Along the lateral edge of the ear
What could be used as a local anaesthetic for cannula placement?
Emla Cream
What gauge of cannula would you use for small cats and rabbits?
22 gauge (blue)
What gauge cannula would you use for cats and most other animals?
20 Gauge (pink)
What gauge needle would you use in dogs over 20kg?
18 gauge (green)
Describe the maintenance of cannulas in patients
Check regularly and flush every 6 hrs with heparinised saline
Swab ports prior to injection
Describe 6 problems with equine cannulas
Extravasation (leaking of IV fluids into extravascular tissues) Thrombosis Thrombophlebitis (inflammation of vein) Infection Emboli
Define Ambulatory infusion
Animal is freely mothin without need for tethe to connect catheter (fitted with jackets)
Define biocompatibility
Good toleration of implanted tissues
Define biofilm
Coating which develops on implanted materials derived from the animals tissue fluids and cells
Define dishecence
Bursting open or splitting along natural or sutured lines
Define friction coefficient
Surface coefficient influences how easily a catheter can be inserted into a blood vessel
Define cannula septum
The thick polymer diphragm allowing sealing a vascular access
