Asr-Airway Maintenance

Front 1

Positioning may not be enough for airway maintenance if...

Back 1

• head in poor anatomical position for surgical access
• positioning/restraint does not allow easy access or re-positioning (stereotaxic)
  
• animal has significant oral/respiratory secretions or potential for stomach/rumen regurgitation
  

Front 2

Face mask

Back 2

• Good low techmethod to deliver gas to theanimal’srespiratory system and notto the general room
  
• Notperfect as the seal is not gastight and there willbe some leakage into the room
  
• Leakage of inhalantanesthetic agents may be dangerous
  

Front 3

Endotracheal Tubes

Back 3

• Maintain a patent airway
  
• Protectairway from foreign material
  
• Allow use ofpositive pressure ventilation·
• Effective delivery of oxygen,inhalant anesthetic agents,and directed test compounds
  
• Suctionof trachea or bronchi
  
• May be made ofpolyvinyl chloride, silicone,plastic, or rubber
  

Front 4

Why is red rubber not advised for use as an endotracheal tube?

Back 4

• due to a propensity for cracking
• difficulty in cleaning
• opacity
  

Front 5

Types of Endotracheal Tubes (2)

Back 5

• Cole Endotracheal tubes
  
• Murphy Endotrachealtubes
  

Front 6

Cole Endotracheal tubes

Back 6

• Uncuffed
  
• Have a “shoulder”that leads to a thinner tip
• Shoulder “seals” against the arytenoidcartilages
  
• Should not contactthe larynx to avoid pressure on laryngeal cartilages which can cause laryngealdilation
  
• Choice ofa proper end diameter (laryngotracheal portion of tube) should create a seal
  

Front 7

Murphy Endotrachealtubes

Back 7

• Cuffed
  
• Allows abetter seal and doesnot require precise tip/shoulder placement
  
• Over-inflationcan rupture the cuff or cause pressure trauma to the airway(ischemic injury, mucosal damage, andultimately tracheal strictures)
  
• Recommendedpressure of air in cuff 10-25 mm Hg
  
• May bereinforced or armored with wire/plastic to prevent kinking
  
• Will have smaller interiorlumens, which can increase resistance to airflow
  
• May bereinforced/colored to preventbreaching by laser lightduring oral procedures
  

Front 8

Murphy Endotracheal tubes

Back 8

Front 9

Cole Endotracheal tubes

Back 9

Front 10

Laryngoscope

Back 10

• Useful for visualizing the glottis and allow easier intubation
  
• do not irritate epiglottis with laryngoscope
  
• holding epiglottis with laryngoscope may be traumatic
  

Front 11

2 Types of laryngoscope blades

Back 11

• Miller
  
• Bizarri-Guiffrida
  

Front 12

Miller Blade

Back 12

Straight

Front 13

Bizarri-Guiffrida Blade

Back 13

Curved

Front 14

Horse,cow, sheep, and goat Airway Concerns

Back 14

• Usually areeating prior to induction, may require flushing debris from the mouth to allow visualization and to not carrydebris into the bronchi
  
• Lubricationof the tube with watersoluble lubricants is helpful
  
• Visualization may be difficult due to the distance from the mouth to the epiglottis
  

Front 15

Cat Airway Concerns

Back 15

• Difficultvisualization
  
• Pressure under theneck will shift the soft palateand obscure the view
  
• Inadequately anesthetized animals may bite down onfingers within the mouth
  

Front 16

Rabbit Airway Concerns

Back 16

• Presenta very small glottis with poor visualizationfrom the mouth
  
• Extending thehead back is helpful during blind intubation
  
• Carefully observe condensation or listen for breath sounds while slowlyadvancing tube to allow adequate feedback
  
• Following a guidecannula may be useful

Front 17

Rodent Airway Concerns

Back 17

• Small sizemakes visualization difficult
  
• Using a guidecatheter or retrograde guidetube may help
  

Front 18

Swine Airway Concerns

Back 18

• Intubationis potentially dangerous due to the false pockets which are highlyvascularized pouches outsidethe trachea
  
• If irritatedthey may bleed profusely
  
• Prone tolaryngospasm
  
• Tube may binddue to sharp angle of route from the mouth into the trachea
  
• Gently twisting the tube while advancing is beneficial
  
• Lubricationof the endotracheal tube is important
  
• As analternate method for intubationof swine, place pig in dorsalrecumbency to which may straightenthe pathway for the endotracheal tube
  

Front 19

Ruminant Airway Concerns

Back 19

• will regurgitaterumen fluid and saliva
  
• Lowerhead below chest level and/or place a rumen tube and collection bag
  
• Rumen tube willalso prevent rumen gasdistension