Endotracheal Intubation of Dogs and Cats (Anesthetist) A&A Pages 97-99 & 245-251

Endotracheal Intubation Flexible tube, placed inside trachea of an anesthetized (induced) patient, used to transfer gases directly from the anesthesia machine to the patient’s lungs, therefore securing the airway. Page

Advantages to Cuffed ET Tubes Dead air space reduced  increase efficiency of gas exchange with inhalation anesthetics Anatomic dead space – This is good for two reasons: 1. 2. Efficient manual ventilation can be provided PPV Reduces the risk of pulmonary ______________ What might be aspirated?

More advantages Secretions can be removed with suction catheter through the ET tube Drugs can be easily administered in emergency (route = ____) Dosage =

Challenges to Intubating Overzealous efforts to intubate can damage anatomy Esophageal intubation Tube can be left too far cranial Tube can be inserted past tracheal bifurcation Pressure ___________ from over inflation of cuff

Types of ET Tubes- Materials

Types of ET Tubes Murphy tubes Magill tubes: Cuffed or non-cuffed Murphey eye- distal end of tube Purpose: Magill tubes: No Murphey eye

Types of Cuffs High volume, low pressure cuffs are ideal Posey Cuff Inflator

Cuff Inflation Recheck every 30 min of surgery – especially after moving or repositioning patient How can you check cuff inflation? Most important for which type of procedures?? If you are running anesthesia for longer than 2 hours, you can reposition the ET tube slightly to ensure pressure necrosis does not happen. IMPORTANT: Must deflate cuff before moving tube! *Even in emergencies*

Additional Types of ET Tubes Cole tubes Laser specific tubes

Selecting an ET Tube DIAMETER Weight based is only a guideline! Brachycephalics: Obese patients: Palpation is more accurate; requires more practice Cats: 3.0-4.5 mm tubes Can use width of space between the nostrils as a guide

Positioning an ET Tube LENGTH- measured in centimeters If you extend into only one bronchus:

Positioning an ET Tube LENGTH If tube extends past patient’s nose  Increased _____________ dead space How might we solve this?

Intubation Techniques 1. Visual 2. Blind Used in dogs and horses NOT suitable for cats, very small dogs, or patients with edema, swelling or trauma 3. Tactile Cattle, large exotics, a few large dogs Finger holds down the epiglottis Slide tube into trachea using your finger as a guide

Feline Intubation Small oral cavity and sensitive larynx Vocal cords tend to quickly close and push tube to side Due to swallowing reflex or contact with end of ET tube  causes ______________________. Can be reduced by application of topical anesthetic Apply 0.1 cc of _______________ on glottis *Try to get 0.05 ml on each arytenoid

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Maintaining an ET Tube Once you have checked placement and patient is stable, watch for: Kinks or bends ALWAYS disconnect from breathing system when repositioning Watch for weight of breathing system tugging on ET tube Don’t place items on patient’s chest! If you have a “bad lung” keep that one down Positioning require head tilted down? Regurgiation?

Extubation Process Removal of tube too early can cause respiratory distress Waiting too long can cause patient to bite tube in half Pay close attention to reflexes during this time! Exceptions to completely deflating the cuff: VIDEO

Post-op Advice to Owner Patients may cough immediately post-op Should not be severe or continue to get worse Is noticed if there was a rough intubation Advising owner will avoid phone calls and later explanations!

Complications Before You Even Start Unclean equipment (we reuse ET tubes!) Leaky cuff/damage Check before use, during surgery, and while cleaning

Complications While Placing Tube too small Not getting enough inhalant ax  Like breathing through a straw  Easily become blocked with mucus  Tube too large Damage to anatomy Tube is too long Hypoxemia and atelectasis/decreased tidal volume

Complications While Placing Over-inflation of cuff: Under inflating cuff = No seal created Breathing room air Staff breathing inhalant Aspiration likely: Vagus nerve stimulation: Parasympathetic response  bradycardia, apnea, cardiac arrhythmias What class of premed can help prevent this response?

Complications During Ax Dislodged tube Not tied securely? Coughs out (cats) Not disconnected while repositioning Weight of hoses & machine pulls tube out Restricted air flow Bevel against wall of trachea What can help prevent this? Kinks-extreme head position, over edge of table, floppy tube

Videos http://www.youtube.com/watch?v=3EDRvvGp OZk&NR=1 - intubation of a dog http://www.youtube.com/watch?v=CGjGTfP_ Bs0 – intubation with cuff