Exotics: Anaesthesia of Exotics Flashcards
What are the defenitions of ASA 1-5?
ASA 1- normal healthy patient
ASA 2- mild systemic disease
ASA 3- Obvious systemic disease
ASA 4- severe systemic disease, constant treat to life
ASA 5- not expected to survive without the operation
What avian patients are of specific concerns?
No commonly kept
* Ratites
* Cranes
* Flamingos
* Charariforms (waders)
* Penguins
* Marine/diving birds
What are general considerations for avian anasethesia?
- High incidence of chronic and subclinical disease
- Susceptiple to heat loss and hypothermia
- Most species no domesticated- peri-anaesthetic stress
- Small species- difficult IV access, limited monitoring
- > morbidity/mortality
- What species do not have nostrils?
- What is the route of air through nostrils?
- Cormorants, pelicans, gannets
- Nasal cavities to infraorbital sinuzes to cervico-cephalic air sacs- reduces in diameter
Diameter > trachea
Glottis not visible in flamingos
- What species do not have nostrils?
- What is the route of air through nostrils?
- Cormorants, pelicans, gannets
- Nasal cavities to infraorbital sinuzes to cervico-cephalic air sacs- reduces in diameter
Diameter > trachea
Glottis not visible in flamingos
How are birds ETT related to anatomy?
- Complete/partiall overlapping rings- uncuffed ETT
- Proximal narrowing of lumen- ETT advancment
- Long complez shapes (cranes, swans) > dead space
- Bifurcated in some species
What is the syrinx?
What can cause a complication with ETT in pigeons and ducks?
Syrinx- bifurfaction of major bronchi responsible for vocalisation during insp/expiration
Tracheal mucus can cause partial/complete ETT obstruction increased in pigeons and ducks
- Which position reduces ventilation of birds and why?
- What can compress air sacs?
- reduced ventilation on dorsal recumbancy (pecoral muscles weight)
- Compressed by effusions, enlarged organs or fat deposits
Birds have higher O2 demands- counter-current
What are the different air sacs in birds?
Paired
* Cervical
* Cranial thoracic
* Caudal thoracic
* Abdominal
Unpaired: clavicular
Why do birds have a higher tolerance to haemorrhage and anaemia?
Why does renal excretion of drugs need to be considered before use?
RBCs have a shorter half life
Renal portal system
How should bird be prepared before anaesthesia?
- Weight taken
- Complete clinical exam
- Fasting- not advised <500g, 2-4 hours for larger, comfirm crop empty
- If possible correct any abnormality prior to anaesthesia: glucose
- Eye lubricant
- Mentation- hypoglycaemia, bradycardia, dyspnoea, neuro
- MMs- pigmented
- African greys- hypocalcaemia
- What are indications for sedation of birds?
- What are the important effects?
- What is often used?
- Clinical exam, short procedures, pre-med for anaesthesia
- Reduces stress of handling, anaesthetic sparing, amnesic effect
- Midazolam 0.5-2mg/kg + butorpahnol 0.5mg/kg IM
reverse with flumazenil = volume midazolam
Other then midazolam what can also be used for sedation?
What is the dose in budgies, rattites, cranes?
Alfaxalone- period of exitability, apnea on induction, variable recovery
Budgies- 10-15mg/kg IM
Birds of prey 10mg/kg IM
Cranes- 7mg/kg IV
When are the following types of drugs used in birds?
Parasympatholytics
Alpha-agonists
Propofol
Parasympatholytics- Bradycardia/CPR situations
Alpha-agonists- birds resistant to effecs, combine with ketamine
Propofol- induction for larger species?
causes resp depression, apnoea, hypotension
What can be used for field conditions for injectable anaesthesia?
Midazolam 1mg/kg + butorphanol 1mg/kg
Ketamine 3-7mg/kg + metomidine 0.07-0.1mg/kg IM reverse with atipamezole
What is monitored directly during GA in birds?
Direct observation
* Palpebral/corneal reflex
* Wing tone
* Feather plucking reflex
* Deep pain/toe pinch reflex
* Sudden feather erection > cardiac arrest
* Clocacal reflex
HR values > or < baseline are abnormal, shifts/trends, oesophageal stethoscope in larger patients
RR chest movements- deep, increased etc
