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)
what breeds tend to have congenital disease which leads to laryngeal paralysis?
dalmations and bull terriers
what are the signs of laryngeal paralysis?
exercise intolerance noisy respiration coughing gagging change or loss of vocal sounds (dysphonia) dysphagia cyanosis and collapse if severe
how can mild cases of laryngeal paralysis be managed?
anti-inflammatories antibiotics where indicated sedative raised feeding reduce stress and manage exercise
how can severe cases of laryngeal paralysis be managed?
unilateral arytenoid lateralisation (tie back)
how is laryngeal paralysis diagnosed?
under light anaesthesia
where is unilateral arytenoid lateralisation (tie back) surgery performed?
left side of neck
what happens during a unilateral arytenoid lateralisation (tie back) procedure?
left arytenoid cartilage is permanently tied open
what is involved in post surgical care of unilateral arytenoid lateralisation patients?
small regular soft meals
avoid dusty food or atmospheres
raised feeding/water
wound management
what must be discussed with the owner prior to unilateral arytenoid lateralisation surgery?
permenant change in phonation
no swimming due to aspiration risk
what is the prognosis for animals undergoing unilateral arytenoid lateralisation surgery like?
positive unless there is systemic neuromuscular disorder involved
what are the 2 key types of palate defects?
congenital
acquired
what are the main congenital palate defects?
clefts of the upper lip, hard and/or soft palates
what are the clinical signs of congenital palate defects?
difficulty feeding and nasal discharge
how are palate defects most often acquired?
trauma (e.g. RTA)
when is surgery to correct congenital palate defects usually performed?
3-4 months of age
how are congential palate defects corrected?
closure of tissues separating oral and nasal passages with minimal tension
how are acquired palate defects closed?
primary closure or second intention depending on damage
what are the most common breeds affected by tracheal collapse?
small and toy breeds (e.g. yorkshire terriers/pomeranians)
what occurs during tracheal collapse?
dorso-ventral flattening of the trachea
what is tracheal collapse due to?
degeneration of tracheal cartilage rings
what are the signs of tracheal collapse?
dry, harsh, loud cough (goose honk)
stridor
builds over weeks or months
what is tracheal collapse often triggered by?
excitement, eating and exercise
what imaging may be used to diagnose tracheal collapse?
right lateral radiographs taken under inspiration and expiration
bronchoscopy
fluroscopy
what are the grades of tracheal collapse?
1-4
describe grade 1 tracheal collapse
25% loss of lumen
describe grade 2 tracheal collapse
50% loss of lumen
describe grade 3 tracheal collapse
75% loss of lumen
describe grade 4 tracheal collapse
total loss of lumen
what is fluroscopy?
real time x-rays where images are gained through constant x-ray exposure
what are the 2 main options for management of tracheal collapse?
medical
surgical
what lifestyle management is involved in managing tracheal collapse patients?
weight loss/management harness not collar avoid smoky atmospheres remove environmental irritants controlled exercise
what cases of tracheal collapse is medical management suitable for?
mild (grade I - II)
what percentage of dogs with tracheal collapse respond well to medical management?
71-93%
what percentage of dogs on medical management of tracheal collapse may be able to have medication gradually withdrawn?
50%
what drugs are involved in the pharmacological management of tracheal collapse?
antitussive therapy
steroid therapy
bronchodilators
when will antibiotics be used when treating tracheal collapse patients?
only if secondary infection is present
what drugs may be used to provide antitussive therapy?
morphine
codine
butorphanol
what is the role of steroids in the medical management of tracheal collapse?
reduction of inflammation
what is the aim of surgical intervention into tracheal collapse?
improve tracheal anatomy and allow increased air flow
what is usually required following surgical management of tracheal collapse?
long term medical management
what grade of tracheal collapse may be treated using surgery?
grade II or higher
what animals undergoing surgical treatment for tracheal collapse have the best prognosis?
those under 6 years old
what are the 2 main surgical management techniques for tracheal collapse?
extraluminal ring prosthesis
intraluminal stent placement
what percentage of patients undergoing extraluminal ring prosthesis procedures report good outcomes?
75-89%
what are the downsides of extraluminal ring prosthesis procedures for tracheal collapse?
invasive
risk must be managed
complications are likely
what are the main complications associated with extraluminal ring prosthesis procedures?
vascular damage tracheal ring migration coughing dyspnoea laryngeal paralysis
what happens during tracheal ring migration following extraluminal ring prosthesis procedures?
sutures come loose on prosthesis and it is able to migrate
why may laryngeal paralysis occur following extraluminal ring prosthesis procedures?
due to iatrogenic nerve damage
what is the benefit of intra-luminal stent placement for treatment of tracheal collapse?
less invasive than prosthesis
what are the disadvantages of intra-luminal stent placement?
stent may fatigue under pressure (e.g. coughing)
excessive inflammation of tissue around trachea post surgery
what must be controlled post intra-luminal stent placement surgery?
coughing - may damage stent
how may coughing be controlled post intra-luminal stent placement surgery?
antitussive medication
what imaging technique is used for intra-luminal stent placement?
fluroscopy
describe surgical prep for extraluminal ring prosthesis
clip and prep
large area of ventral neck
what position must animals undergoing extraluminal ring prosthesis be placed in?
dorsal recumbancy
what must be done for patients prior to induction for tracheal collapse surgery?
pre oxygenation for at least 5 mins
what position must animals be placed in when intra-luminal stent placement is performed?
lateral recumbancy
what are the key considerations about the environment pre and post extubation following respiratory surgery?
calm and quiet
maintain good ambient temp (not too hot!)
what are the key considerations about the patient pre and post extubation following respiratory surgery?
monitoring is key flow by O2 analgesia consider sedation soft food
when should food be offered following respiratory surgery?
later than with normal patients (4-6 hours)
what are the key considerations about the equipment pre and post extubation following respiratory surgery?
SpO2 temp management crash box near ET tube and laryngoscope moisten mouth suction maintain IV access
what is a lateral thoracotomy?
surgical incision performed between the ribs
what is provided by a lateral thoracotomy?
excellent view of one side of the thorax
what are the indications for lateral thoracotomy?
lung lobectomy (e.g. abscessation, neoplasia and lobe torsion)
what ventilation is needed if a thoracotomy or sternotomy is performed?
IPPV throughout
what is a median sternotomy?
surgical incision on the midline through the sternum
what is provided by median sternotomy?
view of bilateral thorax
what are the indications for a median sternotomy?
pyothorax (if drainage ineffective)
mediastinal masses
heart surgery
what type of procedure is a tracheostomy?
emergancy
when is a tracheostomy needed?
physical or functional obstruction of the upper airway tract
what is bypassed by a tracheostomy?
nares, pharynx, larynx and proximal trachea
what are the indications for tracheostomy?
facilitate anaesthesia when airway is compromised
stabilise patient and allow airway management
provide definitive airway until swelling or obstruction is resolved
what conditions may require tracheostomy?
laryngeal paralysis
BOAS
foreign body
laryngeal trauma
what level of monitoring is needed for patients with a tracheostomy?
24/7 high level
what must be monitored relating to a tracheostomy?
maintenance of airway
comfort of patient
asepsis maintained
what must be prevented from building up around the tracheostomy?
secretions
why will respiratory secretions increase with the presence of a tracheostomy?
due to presence of tube causing irritation
how can build up in secretions within a tracheostomy tube be prevented?
suctioning
regular cleaning
changing the tube
when should tube cleaning occur when tracheostomy is first placed?
every 15 mins
when can tracheostomy tube care occur once stable?
every 4-6 hours
what must you be continually checking for when monitoring a patient with a tracheostomy?
harsh respiratory sounds dyspnoea distress coughing discharge discomfort swelling, pain or heat in stoma
how often should the stoma of a patient with a tracheostomy be cleaned?
3-4 times a day
if not an emergency what should occur before cleaning or suctioning of the tracheostomy tube?
pre oxygenation for a minimum of 5 mins
what level of sterility is required when suctioning a tracheostomy tube?
aseptic technique
what catheter should be used to suction a tracheostomy tube?
sterile, soft and long
what length should the suction catheter for a tracheostomy tube be?
pre measured so that it reaches no further than the tip of the trach tube
describe how to perform suctioning of a tracheostomy tube
place catheter into trach
one in place turn on suction unit
move catheter in a circular motion while withdrawing for around 15 seconds
light and intermittent use
when should a tracheostomy tube be changed?
if blocked
how can some tracheostomy tubes be replaced?
inner lumen which is easily removed with outer left in place
what happens during a full replacement of a tracheostomy tube?
aseptic technique preoxygenate unless emergent 2 x team members open stay sutures insert new tube
why is humidification of air inhaled through tracheostomy tubes necessary?
tubes bypass normal humidification found in the URT
what can drying of the respiratory tract lead to?
damage to the mucosa leading to inflammation, irritation and thick mucus
dehydration as water is more rapidly lost through breathing
what can aid humidification of air through trach tubes?
humidification filters that attach to tube
0.3-0.5 mls NaCl
nebulisation with sterile saline
how much isotonic saline should be administered through a patients trach tube to aid humidification of air?
0.3-0.5 mls
how often should sterile saline be administered through a nebuliser to aid tracheostomy patients?
10 mins every 2-3 hours
what is the difference between humidification and nebulisation?
humidification is provision of moisture via aerosol, nebulisation provides medication via this method
