Farm Anaesthetics Flashcards
What local anaesthetic is licensed in food producing animals
Procaine
What are issues with the use of procaine as a local anesthetic
Slow absorption
Vasodilator so will often be combined with adrenaline leading to vasoconstriction which can cause tissue hypoxia and necrosis (teat surgery/digit amputation)
Short duration of action <60 mins
Advantages of lidocaine
Provides surface analgesia
Fast acting
60-90 min duration
Low irritant
Good safety
Not vasodilating
Xylazine advantages/disadvantages for sedation
Very good analgesic/sedative. Licensed for cattle
Can cause ruminal stasis, increased salivation and uterine tone
Unsuitable for some use if more than 1 painful stimulus
Should not be used in heat
Seizures if intra-carotid
Xylazine dosing
As pre-med 0.1mg/kg IM
As anaesthetic combination with local 0.2mg/kg IM
Acp facts
No analgesic effect
Causes hypotension
Increases risk of regurgitation in GA
Can cause penile prolapse in the bull (risk of paraphimosis)
Diazepam facts
Expensive
More useful in calves
Good muscle relaxant no analgesia
Pentobarbitone facts
Sedative/anticonvulsant
Main use in hypomagnesemia
1.5-2mg/kg IV provided standing standing for 60-90mins
Avoid in calves
Do not use prior to euthanasia
Give an example of a GA protocol for a cow
Xylazine IV 0.1mg/kg (IM 0.2mg/kg)
Followed immediately by 2mg/kg IM ketamine
10-20min GA
With rapid recovery
Why should bupivacaine not be used
No MRL
Cornual nerve block
Location just below the lateral ridge of the frontal crest ~ halfway between the lateral canthus of the eye and the horn base
Auricolopalpebral block
Needles inserted subcutaneous just anterior to the ear base the point to the dorsal border of the zygomatic arch.
5-10ml injected and massaged locally
Paravertebral block
To block L3 walk forward off L4.
T13 walk forward off L1, L1 walk off the back of L2. L2 walk off the back of L2
