Analgesia 2 Flashcards
Where is COX 1 found and what is its important role?
COX 1 is found along the length of the GIT and its important role is producing mucus which protects against acid in the stomach!
Name 4 areas of the body where prostaglandins play a role?
- Kidney
- CVS
- CNS
- reproductive system
What 3 things do prostaglandins do to vascular system?
- they enhance renal perfusion
- They engance organ flow
- they reduce vascular resistance
What do prostaglandins do to blood vessels?
they are powerful vasodilators.
Where are COX 1 found in the CNS?
On neurones
Where are COX 1 found during pregnancy?
Foetus, amniotic and uterine tissue
Which other cells of the body contain COX 1?
Blood platelets.
What is the rationale behind using COX 1 selective compounds?
E.g. aspirin - to prevent myocardial infarction.
What does COX 1 do in platelets?
Converts amino acids to thromboxane A2 which is a potent vasoconstrictor and aggregator mediator.
Name two things COX 2 selective drugs might be responsible for in humans?
Heart problems and strokes in humans.
When were COX 2 inhibitors discovered?
1991
Name 3 COX 2 selective drugs?
- Carprofen
- Etodolac
- Meloxicam
Why were COX 2 thought to be so beneficial?
Because they protected the stomach and stopped gastric bleeding and ulcers when Cox 1 was inhibited.
Name 2 selective COX 2 inhibitors in humans?
Deracoxib and firocoxib.
Name 3 situations in which COX 2 inhibitors were contraindicated?
Helicobacter pylori gastritis
Bacterial infection
IBD
- COX 2 inhibitors might actually exacerbate the disease (especially in infection)
What role might COX 2 have which was previously unknown?
might have a role in GI defence.
Which NSAIDs are used for peri-operative pain management?
Meloxicam and carprofen.
Are NSAIDs used in ophthalmic preps?
Not very much, tend to use systemic drugs.
What is an important use of piroxicam?
Use in urinary tract - changes slow transitional cell carcinoma gradient in the bladder - part of chemotherapy treatment.
Name an NSAID which can be used locally? Is it licensed?
Ketoprofen - not licensed.
What is used to treat ulcers?
NSAID ulcer prophylaxis.
What happens if an animal has intolerance to one kind of NSAID?
Change to another.
Can Ibruprofen be used in animals?
NO, NEVER USE IT IN ANIMALS!!!
What is paracetamol?
It is NOT AN ANTI-INFLAMMATORY, but has use in analgesia and antipyretic.
What is the mechanism of action of paracetamol?
Mechanism unknown - thought to inhibit COX 3.
In which species should you NEVER use paracetamol?
cats
What is the licensed form of paracetamol for dogs and what else does it contain?
Pardale V (contains codeine)
What kind of dogs can we administer paracetamol to?
With known liver function.
Will paracetamol reduce inflammation?
No, because it is not an anti-inflammatory.
List 9 complications in which animals should not recieve NSAIDs?
- Renal or hepatic insufficiency
- Hypovolaemia - shock, loss of blood
- Gastric ulcers
- Coagulopathies, active haemorrhage
- Congestive heart failure and pulmonary disease
- Spinal injuries (use steroids first and can have paracetamil afterwards IV)
- Pregnancy (except maybe cesarean)
- Shock, trauma (esp head trauma)
- Concurrent use of steroids
What should be encouraged when monitoring patients post-operatively.
Pain scoring.
In terms of analgesia, what is recommended post-operatively?
Multi-modal analgesia.
Name another very effective analgesia which can be used for sedation? What are they synergystic with?
Alpha 2 adrenergic agonists.
Synergystic with local anaesthetics.
How does analgesia prolong the action of LA?
Less blood flow to the area therefore the action of LA is prolonged.
What do alpha 2 agonists inhibit at the synaptic cleft?
They inhibit norepinephrine release, therefore inhibiting sympathetic activity.
Do alpha 2 agonists reduce MAC?
yes they do, they reduce MAC profoundly!
What are the alpha 2 receptors?
There are three subtypes: A,B and C
Where are the alpha 2 receptors found?
Within blood vessels and within the CNS and the PNS.
Which alpha 2 agonist can be administered bucally?
Detomidine
Name 6 things alpha 2 agonists can be used for?
- standing sedation e.g. large animals and equine
- premedication
- TIVA or PIVA
- Epidural
- Rescue analgesia
- One of the only analgesics which can be reversed e.g. atipemazole.
What is ketamine?
NMDA antagonists
What would you use for an RTA of a fractious cat?
Ketamine
Where are NMDA receptors and what are they for?
They are found in the dorsal horn of the spinal cord and they are used in chronic pain.
Can ketamine be used intra-operatively and how?
Add 60mg ketamine to 1L LRS and administer 10ml/kg/hr to dogs
What two things make onset times of drugs differ?
- Route of administration
2. disease
If you are unsure as to whether an animal is in pain or not, what should you do?
Administer analgesia and monitor the situation.
How should NSAIDs be used?
Pre-emtpively.
How long should we provide analgesia for most routine ops?
24-72 hours (2-3 days)
What options (4) do we have for animals in pain in the recovery stage?
- NSAIDs
- Opioids (transdermal patches, long-acting formulations, oral tablets etc)
- LA blocks
- Adjucts for chronic pain e.g. amatadine and gabapentin
Which drugs are advised for somatic pain?
Ketamine - ketamine is very good for bone pain
Which drugs are advised for visceral pain?
NSAIDs.
What do we administer if buprenorphine is not enough analgesic?
Methadone
How quickly does bupivicaine work and how long does it last?
Bupivicaine works within 20-30 mins but lasts up to 6 hours.
What would you administer to an evil dog to knock them out?
Acepromazine, dexmedomidine, butorphanol and ketamine.
What is VAS, DIVAS and Glasgow short form?
They are pain scales.
VAS = visual analogue scale
DIVAS =Direct Interactive Visual Analogue Scale
What is the difference between VAS and DIVAS?
VAS is just done on visual analysis whereas DIVAS includes approaching the animal, making it walk, and palpation of the animal and surgical incision.
