ANX Lect 1 - 5 Flashcards
Anesthesia Triad
Unconsciousness, analgesia, immobility/muscle relaxation
Blood tests→ indicated when
a physical exam suggests a problem. Very important in critically ill patients and recommended in older patients. Also breed specific (Doberman – coagulation)
Anesthetic Risk
species- day- %
Horse (7 days) – 2.1%
Dog (48 hours) – 0.17%
Cat (48 hours) – 0.24%
Rabbit (2 days) – 1.39 %
Mortality by species:
Horse> Rabbit> Cat> Dog> Man
Anticholinergics: Atropine, Glycopyrrolate, Hyoscine
o Increase heart rate – prevents or treats drug induced bradycardia
o Reduce salivation – in the past needed with irritant anesthetic gases
Acepromazine
Reduced cardiac sensitivity to epinephrine
Relative fall in PCV and thrombocytes
Mild antihistamine reaction
Acepromazine contraindications
Patient has splenic tumor, DO NOT give ACE because spleen could explode (causes splenic engorgement)
Causes priapism in stallions
Diazepam
water insoluble
Reacts with light, other drugs, and plastic so cant administer CRI or store in syringes
Midazolam
water soluble, can administer as CRI
Shorter acting than diazepam.
Alpha Adrenergic Receptor Selectivity
Xylazine < Detomidine< Romifidine < Medetomidine < Dexmedetomidine
Alpha 2 agonist causes a fall in cardiac output and causes
bradyarrhythmias
Detomidine
licensed for horses and cattle
Not hypnotic, horses stand after massive doses
Interacts with potentiated sulphonamides and cause arrhythmias
Medetomidine and dexmedetomidine
most potent, caused marked bradycardia
gold standard for analgesia
Opioids
receptor provides most analgesia
Mu opioid
Full mu agonist
vs
Partial Agonist
vs
AntagonistFull mu agonist = MAX effect
Partial Agonist = ceiling effect
Antagonist = no effect
Which drug is a partial agonist at the mu receptor
Buprenorphine
Which drug(s) - Antagonists at the mu receptor
naloxone, naltrexone, diprenorphine
Emetics
Morphine, Hydromorphone, Oxymorphone
Fentanyl patches
variable time to onset, variable plasma concentration, unreliable, poor alternative to opioid CRI, potential for abuse, BUT have a long duration and useful in practice!
Remifentanyl
rapid onset/ short acting, unique metabolism by plasma esterases – so can give to liver failure patients.
Neuroleptic + opioid
Neuroleptoanalgesia
Methadone
additional analgesic mechanism, NMDA antagonism
