Analgesia Flashcards
Which analgesic prevent pain via site of injury
NSAIDs
Which analgesic prevent pain via altering nerve conduction
Local anaesthetics
Which analgesic prevent pain via modifying transmission to dorsal horn
Opioids and antidepressants
Which analgesic prevent pain via the central nervous system
Opioids and antidepressants
Describe opioids as an analgesic and give examples
- Effect depends on dose
- Can cause mania, CVS effects, urinary retention etc
e. g. morphine, methadone, pethidine,
What receptors does morphine block and what can it be used for?
OPIOID
Full agonist at mu, delta and kappa receptors
(significantly reduces Minimal Alveolar Concentration and Minimum Infusion Rate)
Can be used for epidural
What receptors does methadone block and what can it be used for?
OPIOID
Norepinephrine and serotonin reuptake inhibitor (mu agonist)
What receptors does pethidine block and what can it be used for?
OPIOID Mu agonist (short acting) Blocks sodium channels - Do not give IV = histamine release
What receptors does fentanyl block and what can it be used for?
Mu opioid agonist
Highly lipid soluble and short acting
GOOD WITH BZD
Describe two actions of local anaesthetics
Affects cell membranes directly
Affects channel functions
What factors affect the action of weak base drugs?
pH = related to speed of onset
Protein binding = affects duration of effect
Potency = lipid solubility
Name three local anaesthetics
Lidocaine, Buprevicaine, Mepricaine
What does IVRA stand for
Intra Venous Regional anaesthesia
How can you reduce risk of toxicity of local anaesthetics
Aspirate (do not want to inject into blood)
Describe intra articulary local anaesthetics
- Injected into the joint post closure
What are soaker catheters useful for?
Placing Local anaesthetic into a surgical site
Describe the action of NSAIDs
Inhibit prostaglanding COX and LOX
Describe the effect of NSAIDS on COX 1
= Produce gastric ulcers (failure to vasodilate blood vessels around the digestive tract)
Name two licenced NSAIDS for Horses
Phenylbutazole
Caprofen
What are the contraindications for NSAID use
- Renal/hepatic insufficiency
- Hypovolaemia
- Congestive heart failure
- Gastric ulceration
Describe NMDA antagonists
e. g. Ketamine
- Can be agent of perioperative analgesia
Describe feline analgesia
Acepromazine or buprenorphine IM
NSAID preop
