Respiratory Surgery Flashcards
in what animals is BOAS seen?
extreme brachycephallic breeds (e.g. french bull dogs/pugs)
how can BOAS be assessed?
using scoring system from grades 1-3 which assesses dyspnoea and laryngeal auscultation before and after a period of controlled exercise
what are the main features of BOAS?
stenotic nares overlong soft palette hyperplastic tonsils everted laryngeal saccules hypoplastic trachea hiatal hernia stertor stridor \+/- laryngeal collapse
what is the effect on the BOAS patient of hyperplastic tonsils?
narrows the airway
what is the effect on the BOAS patient of hypoplastic trachea?
narrows airway
what is stertor in BOAS dogs caused by?
partial obstruction of the upper airways at the level of the pharynx and nasopharynx
what condition is stridor associated with?
laryngeal disease
how does BOAS lead to hiatal hernia?
increased negative pressure created by narrowed airways pulls abdominal tissue through the hiatus
what were the main findings of the study by Ludlow et al (2018)?
observations that can be made about a patient before touching them which may indicate that they have BOAS
what were the conformational risk factors for BOAS for bulldogs found by Ladlow (2018)
moderate to severe stenotic nares
thicker neck
wider and shorter skull
male
what were the conformational risk factors for BOAS for french bulldogs found by Ladlow (2018)
moderate to severe stenotic nares thicker and shorter neck shorter and wider skull proportionately shorter muzzle male
what were the conformational risk factors for BOAS for pugs found by Ladlow (2018)
moderate to severe stenotic nares obese (BCS 7+) proportionately wider distance between eyes wider and shorter skull female
how do stenotic nares affect breathing?
increase resistance to flow through nose
cartilage supports of the nares tend to collapse during inspiration so more effort required to breathe
how does an elongated soft palette affect breathing?
can partially obstruct air flow into the trachea and cause turbulent airflow in the larynx
how is laryngeal collapse graded?
1-3, separate from BOAS grading
what is the main brachycephalic breed that is affected by tracheal collapse?
english bulldog
what are the key considerations when nursing/caring for BOAS animals?
avoid stress/heat
use harnesses not collars
achieve/maintain an ideal body weight
carefully manage exercise regimes to ensure resp effort is reduced
consider when O2 therapy may be needed
educate owner on how to recognise signs of respiratory distress and when their pet needs to come into practice
when is it even more essential that a BOAS animal achieves or maintains its ideal body weight?
pre-surgery
what is involved in the nursing assessment of BOAS breeds?
TPR
MM
SpO2
BOAS grading and ASA grading with vet
what are the main surgical treatments for BOAS?
soft palate resection tonsil resection removal of everted laryngeal saccules nostril resection to correct stenotic nares laser assisted turbinectomy (LATE)
what is a staphylectomy?
soft palate resection
what may be involved in surgical correction of BOAS?
one or more/all (multi-level) of the surgical corrections may be performed to correct BOAS
what is a key benefit of BOAS surgery?
enable easier breathing and prevent development of irreversible long term problems (e.g. hiatal hernia)
what will discussion with the surgeon prior to BOAS surgery include?
ASA grading
what key information must be given to an owner before they consent to BOAS surgery?
full explanation of procedures and risks
what pre-surgical tests should be performed on all animals receiving BOAS surgery?
biochem
haem
what must happen to all BOAS breeds before induction?
at least 5 mins of preoxygenation with O2 kennel or mask
how long should animals be preoxygenated for?
5 mins
what is the purpose of preoxygenation?
delays oxygen desaturation if there is post induction apnoea or intubation takes longer due to anatomy
how can stress through handling of BOAS animals be reduced?
IV placed after pre-med if animal is becoming distressed
what topical medication must be provided regularly to BOAS patients under sedation/GA?
occular lubricant
what equipment may be needed for intubation of BOAS breeds?
good lighting
laryngoscope
urinary catheter to guide and ease intubation
rescue ET tube
what is a rescue ET tube?
ET tube with small lumen that can be placed in an emergency if intubation is proving challenging
what imaging should be performed prior to BOAS surgery?
thoracic radiography - ideally CT
what elements of BOAS are assessed by thoracic radiography?
hiatal hernia
nasal turbinates
what patient prep is required for BOAS surgery?
no clip and scrub
oral mouth rinse
nares wiped with dilute chlorhexadine/iodine
what must be done when rinsing the mouth of an unconscious patient?
pack the throat to prevent aspiration
how should an animal be positioned for BOAS surgery?
sternal recumbancy
2 drip stands at either side of table to attach mouth ties to which will hold the mouth open
what event must you be prepared for during surgery particularly in brachycephalic breeds?
regurgitation
how can you be prepared for regurgitation?
tilted table
prepare suction
what SpO2 should animals remain at during BOAS surgery?
> 98%
what EtCO2 should animals remain at during BOAS surgery?
35-45mmHg
why may BOAS animals have elevated EtCO2 at the start of surgery?
as they have inherent breathing difficulties and may be hypercapnic at all times
what should happen to high EtCO2 in brachycephalics following intubation?
should settle to normal range
what considerations must be made when choosing a circuit for BOAS surgery?
IPPV or manual ventilation may be necessary
what level should MAP be kept at during surgery?
not below 60 mmHG
what should be done if BP falls below 60 mmHg during a procedure?
discuss the possibility of IVFT bolus with the vet
what are the main complications following BOAS surgery?
airway swelling
vomiting and regurgitation
aspiration pneumonia
what is the most high risk anaesthetic period for BOAS surgery?
extubation
when should patients be extubated post BOAS surgery?
later than usual
what should be supplemented in BOAS patients post extubation?
oxygen - mask or flowby
what position should animals recover from BOAS surgery in?
sternal with head elevated
what should be available during BOAS recovery?
suction in case of regurgitation
how intensively must patients be monitored post op?
ICU monitoring chart with constant supervision
what are the key areas of post op care for BOAS surgery?
calm, quiet and stress free environment avoid hyperthermia sedation if stressed home as soon as safe harness only client verbal and written discharge info
what sedation may be used if patient is stressed following BOAS surgery?
dexmedetomidine
what exercise regime is required following BOAS surgery?
restricted to 5-10 mins twice daily for 6 weeks
when are BOAS patients routinely examined post-op?
2 and 10 days
how should animals be fed following BOAS surgery?
wet solid food for 6 weeks post op to limit airway irritation
what are the key treatment elements of BOAS?
weight management
surgical correction
what are brachycephailic breeds at increased risk of when under anaesthesia?
reflux and regurgitation
what happens during laryngeal paralysis?
vocal chords are unable to abduct in response to exercise and respiratory demands
what are the causes of laryngeal paralysis?
ageing changes (degenerative neuropathy)
congenital disease
trauma
cancerous infiltration of the nerve which controls associated muscles
what breeds are predisposed to laryngeal paralysis as a result of degenerative neuropathy?
irish setters and labradors (median age = 9.5 years)