Karteikarten
Practical Aspects of Induction and Maintenance of Anaesthesia
Karten in diesem Stapel (62)
- 1What is the preparation required for anaesthesia?- Induction (and recovery) are risky phases
- Stressful
- Preparation
- Anticipation
- Team approach - 2How is induction of anaesthesia achieved?Administering a drug, usually IV, as a bolus or to effect in to facilitate endotracheal intubation
- Some times achieved by IM or inhalant agents - 3What is it a good idea to fill out before induction, post induction, pre intra and post surgery?A checklist
- 4What equipment needs preparing before induction of anaesthesia?- Anaesthetic machine
- Breathing System
- IV catheter equipment
- Intubation equipment
- Monitoring
- Fluids
- Draw up and label drugs - 5What equipment is required for endotracheal intubation?- Laryngoscope
- Tubes
- Local anaesthetic (cats)
- Tie
- Cuff syringe
- Swab, suction, mask for pre-oxygenation, stylet / bougie - 6What features of the endotracheal tube need to be considered?- The size (width) of the tube
- The length - 7How can you select the right size endotracheal tube?- Direct palpation of the mid neck region of the trachea
- Assessment of the width of the nasal septum
- Previous experience - 8What is the general rule with sizes of the endotracheal tube?10mm ETT is suitable for a 20kg dog, an 8mm ETT for a 10kg dog and a 4.5-5mm uncuffed tube is suitable for a typical adult cat
- 9What considerations are there with brachycephalic breeds?- Preparation is key because may need to assist breathing quickly
- May have hypoplastic tracheas so smaller required - 10What is the rule for using an ETT?Largest tube than can be inserted and atraumatically should be used as the resistance to breathing increases 16 fold as the radius of the tube is halved
- 11What is considered with the length of the ETT?- Cut to size
- Connector should be level with the incisor arcade and the tip at the point of the shoulder - 12What happens if the ETT is too long?Resistance and dead space will increase and there is the risk of endobronchial intubation resulting in one lung ventilation and hypoxaemia
- 13What happens if the ETT is too short?- May be dislodged and the cuff may damage the larynx
- 14Why is the use of a cuff in cats controversial?Trachea can be easily damaged in cats
- 15What are the pros and cons of using a cuff?Uncuffed:
- can use a larger diameter ETT
- less trauma to the trachea
Cuffed:
- allow mechanical ventilation
- extra care needed when moving animal - 16What should occur when moving an animal that has an ETT?Great care
- when changing recumbency the ETT should be disconnected from the breathing system after turning the vaporiser off - 17How do you prepare the animal?- Thorough pre-anaesthetic assessment
- Anticipate problems
- Optimise condition
- Premedication
- Time for drugs to work
- Calm environment
- Avoid stress - 18What is the technique for induction of anaesthesia?- Minimal effective restraint:
i. animal in sternal or lateral recumbency
ii. no hands around neck
iii. one hand holds the upper jaw just behind the canines (use a tie?)
iv. the other hand supports the base of skull
- Never scruff cats
- Optimise ventilation - don't compress chest - 19What is done in the induction of anaesthesia?- IV catheter
- Pre-oxygenation
- Monitoring equipment
- IV agent
- Fluids - 20What is it always a good idea to do first before trying to place the endotracheal tube?Preoxygenate for 2-5 mins with 100% oxygen at 3l/min
- 21How can you test the depth of sedation?Assess jaw tone (no fingers in mouth) and palpebral reflex
- 22What is sprayed on cats arytenoids to prevent laryngospasm?Lidocaine
(check concentration and make sure that you're not going to overdose the cat) - 23What is the point at which an endotracheal tube can be placed?Palpebral reflex is sluggish and jaw relaxed with no tongue curl when the mouth is opened
- 24In what position should the head be held for placement of ETT?Head and neck slightly hyperextended to allow visualisation of larynx
(straight line) - 25How should the ETT be placed?- Laryngoscope blade on base of tongue under epiglottis
- Gentle pressure on base of tongue to displace soft palate
- Advance ETT between arytenoids
- Cough or reacts, additional injectable agent given
- Resistance encountered, a gentle twist
- Visually confirm placement - 26What occurs after the tube has been placed?- Tied in place around the connector and then head or muzzle
- Connected to breathing system and start administering 100% oxygen - 27How do you inflate the cuff?- Inflate it
- Listen carefully to the escape of air around the tube while your assistnat closes the APL valve and squeezes the reservoir bag at pressure of 15-20cmH2O
- Inflate the cuff until no gas is heard to be escaping - 28What is the gold standard for confirming tracheal intubation?Capnography
- 29How else can it be confirmed that the tube is positioned correctly?- Visualisation of the tube between the vocal folds
- Condensation inside tube
- Appreciation of air movement (don’t use hair)
- Don’t press on thorax!: False positive, Reflux, Reduce FRC - 30What happens if the cuff is leaking?- Difficult to achieve a stable plane of anaesthesia as volatile agent is not being delivered effectively
- Waste anaesthetic gas pollution
- Airway not protected in event of regurgitation and risk of aspiration - 31What is the risk if the cuff is over inflated?Tracheal damage
fibrosis, necrosis, tears, rupture - 32How should the ETT be placed if there is cervical damage?Animal in lateral recumbency
- 33What should happen is the animal is at risk of regurgitation/vomiting?- Head and neck kept extended
- Not to compress stomach
- Quick induction and intubation
- Cuff inflated whilst head up
- Head can be lowered once inflated cuff - 34What is essential with an animal with intracranial disease during ETT?Don't increase the intracranial pressure anymore
- 35When is induction with a mask and inhalant gas performed?Puppies
Cats
Exotics
When an IV catheter cannot be placed before induction - 36What are essential features of the mask for inhalant induction agent?- Proper size
- Transparent
- Takes longer with mask than IV
- Not recommended in patients at risk of regurgitation/aspiration
- Higher pollution - 37What is the issue with inhalant agents?Pungent and cause airway irritation with consequent laryngeal spasm, salivation and increase airway secretions
- Isoflurane more aversive than sevoflurane - 38When is induction of anaesthesia with a chamber and inhalant agent used?Fractious cats and exotic animals
- 39What are features of the chamber and inhalant agent for induction?- Chamber appropriate size, transparent and airtight
- Connected to non-rebreathing system
- Cage opened once anaesthesia is induced and ambient pollution should be minimised by closing it immediately after moving animal - 40When can pharyngostomy intubation be used?When oral surgery is being performed
- Need to be trained - 41What are the most common complications during induction of anaesthesia?- Apnoea
- Laryngospasm
- Failed intubation
- Airwar occlusion - 42Why does apnoea occur?Generally caused by respiratory depression after administration of induction agent:
- Administered over 60-90 seconds at appropriate dose
- Assisted ventilation should be available - 43In what species is laryngospasm most seen?Cats
- 44How should larygnospasm be prevented?Lidocaine on arytenoids, 30-60s before ET intubation
- Attempt intubation when adequate depth of anaesthesia is achieved - 45What should happen is larygnospasm occurs?- Provide 100% O2
- Increase depth of anaesthesia by administering more injectable agent
- Have a stylet and small sizes ready
- If ETT cannot be placed a urinary catheter may be inserted into the trachea via the larynx and the ETT threaded over it
- Consider letting the animal recover / use a larygneal mask airway / facemask rather than repeatedly attempting intubation and causing swelling of the larynx - 46What should occur if there is failed intubation?Confirm using visual inspection and capnography
- Re-insert if oesophageal intubation occurred - 47When may airway occlusion occur?Between sedation and induction of anaesthesia
- Paradoxical ventilation may indicate upper respiratory tract obstruction - 48What should be in a box ready to deal with difficult intubations?- ETT of different sizes
- Stylet
- Urinary catheter
- Laryngoscope
- Lidocaine
- Small oxygen cylinder
- Tracheostomy kit
- Suction device should be available - 49What is the technique of laryngeal mask airways in dogs and cats?- Supraglottic airway device
- Proximal end similar to ETT and connected to an elliptical mask with cuff on the distal end
- Non-invasive method to create an airtight seal
- Correct placement confirmed by capnogram, no audible leak, no abnormal respiratory noise and adequate thoracic excursions during respiration - 50When can laryngeal mask airways be useful?- Difficult airway intubation
- Multiple anaesthetics
- Situations where tracheal trauma should be minimised - 51Why are perianaesthetic morbility and mortality higher in rabbits than cats and dogs?- Underlying and often subclinical disease
- Lack of familiarity
- Small size: difficult placement of IV catheter, difficult doing of drugs, difficult dosing of fluid therapy, problems with equipment
- Challenging endotracheal intubation
- Delicate gastro-intestinal system - 52What needs to be remembered in the preparation of rabbits?- Starving rabbits is not necessary
- Stabilise the rabbit before GA
- Avoid any stress
- Use gentle handling
- Place an IV catheter before induction of anaesthesia: the use of EMLA cream may be beneficial
- Pre-oxygenation may be useful
- Uncuffed endotracheal tubes are generally used in rabbits - 53How might induction of anaesthesia be achieved in rabbits?- IV induction agent (preferable)
- Inhalant agent administered via a mask or induction chamber - 54What are the 3 methods for endotracheal intubation in rabbits?- Blind endotracheal intubation
- Endotracheal intubation with otoscope or laryngoscope
- Endotracheal intubation with endoscope - 55What is blind endotracheal intubation?- Hold the head of the rabbit with your non-dominant hand and extend the neck
- Introduce gently the endotracheal tube down the trachea while listening to breath sounds
- The rabbit may cough when you reach the larynx
- If breath sounds are not heard any more, oesophageal intubation may have occurred - 56What is endotracheal intubation with otoscope or laryngoscope?- Visualization of the larynx is facilitated by the use of an otoscope or laryngoscope
- A boogie or stylette is introduced in the trachea (avoid trauma to the trachea)
- The endotracheal tube is threaded over the boogie or stylette - 57What is endotracheal intubation with endoscope?- Visualization of the larynx is facilitated by the use of an endoscope
- A boogie or stylette is introduced in the trachea (avoid trauma to the trachea)
- The endotracheal tube is threaded over the boogie or stylette - 58What are techniques for use of laryngeal mask airways in rabbits?- Placement of a LMA is usually easier than endotracheal intubation
- The dose of induction agent required to place a LMA is lower than endotracheal intubation - 59What should occur immediately after tracheal intubation?- Peripheral pulses palpated
- Endotracheal tube secured
- Cuff inflated
- Depth of anaesthesia assessed
- Maintenance of anaesthesia monitored
- Hands on monitoring of vital parameters and records made - 60During maintenance of anaesthesia what should happen?- Record data on the anaesthetic record
- Monitor depth of anaesthesia - 61Why should ocular lubrication be applied as soon as possible after induction and regularly during anaesthetic and occassionally post surgery?- Formation of pre-corneal tear film is reduced during anaesthesia and sedation
- Eyes become dry and predisposed to damage, and vulnerable to trauma when moving - 62Why does body temperature have to be controlled for animals during anaesthesia?Body temperature controlled by hypothalamus and so hypothermia is common during anaesthesia
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- Beschreibung
- Foundations of clinical veterinary science - CVS1 (Anaesthesia - Emma Love) Karteikarten am Practical Aspects of Induction and Maintenance of Anaesthesia, erstellt von Rachael Jones am 22/11/2017.
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- Rachael Jones
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