Birds are hard to keep alive... Advances in Drugs Monitoring Understanding of birds
Anaesthesia provides.. Immobilisation Analgesia Muscle relaxation Oxygen Reduced stress?
Better control... Intubation Ventilation
Isoflurane is safer than Adrenaline!
Before anaesthesia, consider. Anatomy URT LRT Physiology Air flow Respiratory movements Small Functional Residual Capacity High Metabolic Rate
Patient Preparation Possible? History and physical examination Further examinations? Pre- anaesthetic blood screens? Acclimatisation Fasting Premedicants?
Really bad news...
Vet preparation Ready for the op? Vet Nurse Assistants Equipment MINIMISE THE TIME SPENT ANAESTHETISED!!!!
Induction Injectable vs gas? Mask vs chamber Restraint for mask One- and- up or five- and- down?
Masks
Intubation: anatomy
Intubation: the tubes!
Problems associated with intubation Blockage Tube smaller species? Positioning? Ventilate? Stricture Species? Type of tube? Cleaning? Length of tube & positioning?
Circuits Mask + elephant tube Consider Resistance Dead space T- piece, Mini- lack, Bain, etc
What if we want to work on the head?
Air sac cannulation?
Maintenance Mask Passive breathing IPPV Manual Mechanical Volumetric Pressure
Important Aspects Temperature!!! Pads Bottles, etc Radiant Eyes Blood loss Position
You do need an anaesthetist
Their emphasis is on monitoring... Appreciate Respiratory rate Lung perfusion Blood oxygenation Heart rate/ regularity Pulse rate/ regularity Peripheral blood flow Body temperature
Effect of Ventilation...
Haven t mentioned reflexes...
Capnography: Why monitor CO2? Carbon Dioxide production is constant and its expired level reflects both cardiovascular and respiratory efficiency All the Capnograph profiles and End- Tidal values you will see can be explained by remembering the above statement It is an early warning system for hypoxia Simply put it tells you that the animal IS breathing and how well it is breathing
What information do we get from Capnography? Capnography gives us continuous information on Expired and Inspired CO2 concentrations Expired CO2 (PetCO2) is a reflection of the PaCO2. There will always be a gradient between PetCO2 and PaCO2 but other than in extreme circumstances, this is usually only 1-4 mmhg In addition to the End- Tidal value the Capnogram shows the levels of CO2 during the complete respiratory cycle The Capnogram waveforms provide a lot of information
Typical Capnogram Phase 0 Inspiration. Rapid fall in CO2 levels as new breath taken Phase I Beginning of expiration and the elimination of gas from anatomical dead space Phase II Alveolar gas mixes with dead space Phase III Main component of expiration. Has a typical positive slope
Peripheral Blood Flow Consider Pulse rate Rhythm Strength
ECG
Reduce wires?
What about the good old pulse ox?
But if you want a sensitive, reliable, reactive anaesthetic monitoring device...
Is there a place for injectables? Field anaesthesia? Or iso + air?? Special species Ratites Total injectableregimes? Sedation only?
Analgesia Do birds feel pain and how to assess? NSAIDs Opiates Local anaesthesia Dissociative agents
Consider analgesia if.. Would the lesion be painful to a human? Is the lesion damaging to tissues? Does the bird display behaviours that may indicate pain? Change in temperament, restlessness, reduced grooming, reluctance to perch, lethargy, reduced appetite, constipation, dyspnoea, lameness, biting/ chewing at wound, tonic immobility
Emergencies Respiratory vs cardiac depression Protocol as in mammals
ABC A B C D F irway reathing irculation rugs luids
Recovery Supervise till standing Extubation Wrap
In summary... Birds are commonly anaesthetised and can be quite stable! Anaesthesia is usually reactive, not planned There is no easy GA!