Equine Anesthesia Flashcards
What are the 5 characteristics that increases anesthetic risk of mortality?
- mares in last 3rd pregnancy
- horses undergoing colic surgery
- # repair for internal fixation
- surgery over 4 hours
- foals less than 1 month & horses older than 12 years
Which premedication will decrease the risk of anesthetic mortality?
Acepromazine
What are the 4 most common causes of death associated w anesthesia?
cardiac arrest
post-operative collapse
fractures
myopathy
What are the 2 most common causes of death during anesthesia recovery?
Fractures
dislocation
What is the normal horse HR?
20-45 bpm
What is the most common arrhythmia?
2nd degree AV block
Which respiratory disease is common in horses over 10 years?
COPD
What are signs of sedation in horse?
head down, droopy lips, sleepy, wide based stance
Which premed is used in combination w other sedatives?
Acepromazine
What are the 3 contraindications of Ace?
hypovolemic
young foal
breeding stallion
What are the alpha adrenoceptor agonists used for premed?
Xylazine
Detomidine
Romifidine
Metetomidine
Which alpha adrenoceptor agonist has the shortest duration of action?
Xylazine
Which alpha adrenoceptor agonist has the least amount of analgesia & ataxia?
Romifidine
What is the major side effect of opioid?
decreased GI motility
Which drug is used for tranquilization in foals under 2 months & why?
Benzodiazepines (diazepam & midazolam) bc few CV & resp effects
What effect does Thiopental have on horse induction?
rapid induction
What effect foes Ketamine have on horse induction?
slower induction, so is the better option of Thiopental
There are lots of combinations for induction anesthesia, but what drug is used in most/all combinations?
Ketamine
Which induction drug is not used in adult horses?
Propofol bc cost to volume
What is the only licensed drug to use for inhalant anesthesia in horses?
Isofluorane
Increasing the vaporizer will do what?
cause more hyperventilation & more hypotension
What setting should the vaporizer be on initially & then for maintenance?
4-6% then 2-3%
What should the oxygen be on initially then for maintenance?
6-10 L/min then 5-10 ml/kg/min
What is the maximum duration for TIVA w inhalant anesthesia & why?
2 hours bc accumulation
What does TIVA consist of?
GG
Alpha 2 agonist (Xylazine, Detomidine, Romifidine)
Ketamine
Why is it important to monitor arterial BP?
bc there is an association btwn BP monitoring & occurrence of myopathy
Which arteries can be used for arterial BP?
transverse facial a
facial a
digital a
What is the aim of MAC?
> 70 mmHg
What does the pulse ox measure & what is the minimum accepted value?
Hb saturation
90
What are the pain management options for horses?
NSAIDs
Alpha 2 agonist
Opioids
What is the risk of hypotension during anesthesia?
reduced organ perfusion & increased risk of myopathy
How do you treat hypotension?
decrease vaporizer
increase rate of fluids
vasoactive drugs
What is the risk of hypoventilation during anesthesia?
leads to resp acidosis & increased risk of arrhythmias
How do you treat hypoventilation?
decrease anesthetic depth (if possible)
IPPV
What is the risk of hypoxemia during anesthesia?
decreased O2 delivery to tissues
How do you treat hypoxemia?
increase FiO2 mechanical ventilation beta 2 agonist change position reduce pressure from abdominal contents
How do you prevent myopathy?
minimum MAP of 70 mmHg
What are the characteristics of a better recovery?
longer recovery, shorter surgery, less invasive surgery
What inhalant anesthesia is the best?
Halothane
Donkeys & Mules are less sensitive to which anesthetic drugs?
alpha 2 agonist
Which injectable anesthetic drug are donkeys & mules more sensitive to & what does it cause?
Guaifensin causes respiratory arrest
