Anesthetic Procedures and Techniques in Dogs



Anesthetic Procedures and Techniques in Dogs




Overview


Anesthetic procedures and techniques for dogs are designed to safely, effectively, and economically produce calming, sedation, analgesia, and unconsciousness. Techniques using single drugs have largely been abandoned in favor of techniques that combine drugs from different classes in reduced doses, theoretically reducing unwanted side effects and toxicity. The advantage of combination drug therapy over single-drug therapy is a more controlled anesthetic state by manipulation of hypnosis, analgesia, and muscle relaxation. Combination drug therapy requires a comprehensive knowledge of the pharmacology of anesthetic drugs, their interactions, and potential side effects.




General Considerations




A variety of anesthetic procedures and techniques can be used to safely produce chemical restraint and anesthesia in dogs. Local anesthetic techniques (see Chapter 7) should be considered to augment analgesia.


II The choice of anesthetic regimen is influenced by the following characteristics:



III Whenever possible, drugs that are reversible should be used


IV Endotracheal intubation should be performed whenever possible to ensure a patent airway


Careful monitoring is mandatory to recognize and treat untoward drug effects


VI Food and water should be withheld for approximately 4 to 6 hours before surgery, except in very small, very young, or diseased dogs



Preanesthetic Evaluations (See Chapter 2)




Review history and current drug therapy


II Perform a physical examination


III Review available laboratory data


IV Formulate a specific anesthetic plan (Fig. 20-1)




Intravenous (IV) catheter placement is recommended



VI Gather appropriate equipment and supplies



Mouth gag or speculum


Endotracheal tube (see Chapter 11)



1. Select diameter of cuffed endotracheal tube based on the dog’s size, breed, and procedure; brachycephalic breeds usually have smaller-diameter trachea (Table 20-1); a reinforced tube (kink resistant) should be used for procedures that may require severe curvature of the neck (e.g., ophthalmic surgeries, cerebrospinal fluid tap)



2. Check cuff for leaks by inflating with air; deflate before intubation


3. Use a stylet for small-diameter, endotracheal tubes, and reinforced tubes


4. Use an uncuffed endotracheal tube in very small dogs (Fig. 20-2)



5. Use a small amount of sterile lubricant


Laryngoscope (Fig. 20-3)




Anesthetic machine and breathing system



1. Size and type of system determined by dog’s size



2. Rebreathing bag should be approximately five times the tidal volume. Tidal volume (VT) is 10 to 15 mL/kg of body weight (e.g., 5 kg × 10 mL/kg = 50 mL VT)


3. Refill carbon dioxide absorbent canister if material is exhausted (discolored or dry)


4. Evaluate anesthetic system for possible malfunctions (see Chapter 12)



5. Connect the waste gas scavenging system to the anesthetic circle or nonrebreathing system


Fresh gases



IV administration supplies



Drugs



Monitoring equipment (see Chapter 14)


Sep 6, 2016 | Posted by in SUGERY, ORTHOPEDICS & ANESTHESIA | Comments Off on Anesthetic Procedures and Techniques in Dogs
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