Equine Respiratory Surgical Approach

Question 1

what is dynamic endoscopy?

Answer 1

where the larynx and pharynx is examined during fast exercise which mimics the conditions when performance is suboptimal

Question 2

name some of the elective surgical procedures of the equine URT

Answer 2

aryepiglottic fold resection

tie back (prosthetic laryngoplasty) + hobday

tie forward (laryngeal advancement)

soft palate cautery

epiglottic entrapment release

sinus surgery

tracheostomy

Question 3

name some of the emergency surgical procedures of the equine URT

Answer 3

emergency tracheotomy
occlusion of artery in guttural pouch mycosis cases
trauma
thoracic drain placement

Question 4

should you starve a horse pre-op?

Answer 4

2 hours for GA, preferable to starve for standing sedation in case it escalates to GA

Question 5

what are the advantages of standing sedation?

Answer 5

reduced GA risks

may reduce costs

anatomical advantages - access/position, reduced haemorrhage

less facilities and experts required

Question 6

what are the disadvantages of standing sedation?

Answer 6

not all horses have suitable temperament

less control of situation if complications arise

need environmental control (noise and movement)

limited duration - speed critical

may need to change plan to GA if complications arise

Question 7

what vessel is used for IV catheter placement for standing surgery?

Answer 7

left jugular vein

Question 8

why is the left jugular vein used for IV placement in standing surgery?

Answer 8

the left recurrent laryngeal nerve is prone to pathology - placing catheter in left jugular avoids bilateral damage to the laryngeal nerves if there was a perivascular reaction

Question 9

what drugs are typically used for standing sedation in horses?

Answer 9

ACP premed 
a2 agonist (detomidine) and opioid combination

Question 10

what types of regional local anaesthetics are used in standing surgery?

Answer 10

nerve blocks
local infiltration
(lidocaine/mepivacaine/prilocaine)

Question 11

why might a sinus flap surgery (standing) be performed?

Answer 11

treatment of sinus emphysema, sinus cysts, ethmoid haematoma

Question 12

what are the advantages of GA for horse surgery?

Answer 12

more control of horse - safer in fractious patients

less time pressure (but takes longer)

less noise/movement sensitive

oxygen available

Question 13

what are the disadvantages of GA for horse surgery?

Answer 13

extra cost/expertise/time/facilities

1% risk of mortality in healthy horse

airway supervision required at all times

longer duration

Question 14

which elective procedures are usually done under GA rather than standing?

Answer 14

tie forward

soft palate cautery

Question 15

which elective procedures are usually done standing rather than GA?

Answer 15

sinus surgery

tracheostomy

Question 16

which emergency procedure is usually done under GA rather than standing sedation?

Answer 16

occlusion of artery for guttural pouch mycosis cases

Question 17

why is GA avoided in horse respiratory surgery unless required?

Answer 17

lateral/dorsal recumbency in the horse is likely to cause significant ventilation/perfusion mismatch

Question 18

what equipment is required for laser equine surgery?

Answer 18

PPE vital - goggles and signage
unlocking device for machine
spare fibre, ceramic scissors, fibre stripper
suction - toxic gases

Question 19

which anaesthetic gas cannot be used during laser surgery?

Answer 19

nitrous oxide - fire hazard

Question 20

which elective surgeries can be done via laser?

Answer 20

ventriculocordectomy (Hobday)
aryepiglottic fold resection
sinus surgery (after initial hole is made)

Question 21

how can you achieve a patent airway intra-operatively?

Answer 21

oro/naso/laryngotracheal tube

tracheostomy tube

Question 22

how can the airway be protected against aspiration intra-operatively?

Answer 22

use a cuffed tube

suction/absorption (swabs)/drainage

Question 23

what is the aim of soft palate cautery?

Answer 23

attempts to create scarring and tighten the soft palate to prevent dorsal displacement from occurring

Question 24

what are the possible surgical post-op complications?

Answer 24

swellings may compromise airway - always have tracheostomy kit available

inhalation pneumonia - monitor breathing and temp post-op

Question 25

how should a horse be fed after respiratory surgery?

Answer 25

moist, soaked hay/haylage always

high haynet for tie forward to avoid pressure on sutures

from floor for remainder - allows drainage from airway

Question 26

what analgesia is commonly given after respiratory surgery?

Answer 26

NSAIDs

topical throat spray

Question 27

what is the post-op management for a laryngostomy?

Answer 27

site is usually left open to drain as contaminated surgery

laryngostomy tube placed at end of surgery for recovery and left in situ overnight

always occlude the tube before removal to ensure horse can breathe on its own

Question 28

where would a chest drain be placed for fluid collection?

Answer 28

ventral thorax

Question 29

where would a chest drain be placed for gas collection?

Answer 29

dorsal thorax

Question 30

what is a thoracoscopy?

Answer 30

procedure to investigate and/or treat pleural/pulmonic disease (exudate from pleuropneumonia, neoplasia, pneumo/haemothorax)

Question 31

how is a thoracoscopy perfomed?

Answer 31

under standing sedation
set up as laparoscopy
suction and oxygen essential

Question 32

what is the difference between a tracheostomy and a tracheotomy?

Answer 32

tracheostomy = long-standing, stoma or metal tube 
tracheotomy = temporary emergency airway access, plastic tube

Question 33

why might a patient require an emergency tracheotomy?

Answer 33

direct airway obstruction e.g. laryngeal obstruction/paralysis/spasm/oedema, tracheal collapse
external obstruction e.g. abscess, strangles, oedema following trauma