Equine Field Anesthesia Flashcards Preview

Module 14 > Equine Field Anesthesia > Flashcards

Flashcards in Equine Field Anesthesia Deck (20)
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1
Q

what patient history is important

A
  1. signalment
  2. medical history
  3. anesthesia relevent information (prev anesthesia, time of last meal, allergies/intolerances)
  4. physical exam
2
Q

what is the pre-anesthetic preparation

A
  1. starvation period (not for suckling neonates)
  2. patient weight
  3. IV access
  4. wash out mouth with water
  5. clip the surgical area
3
Q

why is IV access essential

A

top ups and emergency drugs

irritant drugs (thiopentone, guaifenesin)

4
Q

what is an example premedication recipe

A
  1. acepromazine: 10-30 micrograms/kg IM 40-60 mins prior to induction
  2. NSAIDs +/- antibiotics
  3. romifidine 40-100 micrograms/kg IV (detomidine, xylazine) + butorphanol 20-50 micrograms IV or morphine 0.1-0.2 mg/kg slow IV
5
Q

how is induction done

A

free fall

swing gate

controlled recumbency if possible

keep owners away

6
Q

what is used for induction

A
  1. ketamine/benzodiazepine

standard protocol

reliable and controlled

prior sedation mandatory

7
Q

what is an example induction recipe

A
  1. ketamine 2.2 mg/kg + diazepam 50 micrograms/kg

mix in same syringe

8
Q

what is the equine triple drop

A

500 ml GGE + ketamine + alpha 2 agonist

  1. 500 ml GGE 10% + ketamine 1500 mg + xylazine 750 mg (starting rate 0.66 ml/kg/h)
  2. 500 ml GGE 10% + ketamine 1000 mg + detomidine 10 mg (starting rate 1 ml/kg/h)
9
Q

what are the advantages of the triple drip (3)

A
  1. easy
  2. cardiovascular function increases
  3. respiratory funciton increases (increased PaO2 and decreased PaCO2), preservation of hypoxic pulmonary vasoconstriction
10
Q

what are the triple drip disadvantages (4)

A
  1. horses appear to be light: swalloing, blinking, twitching (ketamine effect is not indicative of inadequate anesthesia)
  2. respiratory pattern changes with TD overdose (can be confused with inadequate anesthesia)
  3. for 90 min max
  4. drug accumulation: poor recoveries possible
11
Q

what would a goo anesthetic protocol be for a 18 month TBX colt for a standard castration (not standing)

A

short procedures

standard premedication

induction: ketamine/diazepam ~ 20 min recumbency (not 20 min surgical anestheisa)

usually adequate for experienced vet

12
Q

what would a good anesthetic protocol be for a 12 year old TB with penetrating sinus injury that requires exam and flushing under GA

should take 30-40 min

A

longer acting alpha 2 agonists (not xylazine)

standard induction

q(7-)10 min: 1/3 induction dose of ketamine –> regardless of how horse looks

max of 3 top ups

OR

triple drip

13
Q

what would a good anesthetic protocol be for an 8 y TBX that requires GA to remove a splint bone fracture

60-90 min procedure

A

triple drip technique

standard sedation and induction

tendency to use same alpha 2 agonist for premed and triple drip

infusion rate initially at set rate and then adjusted to effect

14
Q

what is important in procedures longer than >60 mins

A

ideally ability to ventilate

otherwise atelectasis formation –> dead space and V/Q mismatch increases and potential for hypercapnia and hypoxemia

15
Q

what are the advantages to intubation

A
  1. airway maintenance and protection
  2. IPPV possible if large animal ventilator available
  3. easy to perform
16
Q

what are the disadvantages to intubation

A
  1. ETTs expensive
  2. IPPV not an option without ventilator
17
Q

how is monitoring done

A
  1. pulse rate + quality + rhythm
  2. auscultation
  3. resp rate + patter
  4. MM colour + CRT
  5. if available –> pulse oximeter, ECG, capnograph
18
Q

how is oxygen supplemented

A

nasal/intra ETT insufflation at max flow (10-15 L/min)

19
Q

what results in a longer recovery

A

triple drip

20
Q

how should recovery be done

A
  1. leave alone in field
  2. quite
  3. longer procedures with trip drip (additional sedation? nasal tubes)
  4. assist?
  5. forced recumbency?
  6. keep owner away
  7. don’t leave until horse is standing and stable