Felis ISSN 2398-2950

Local anesthesia: intraoral

Contributor(s): William Gengler, Margherita Gracis

Introduction

  • General anesthesia General anesthesia: overview  and endotracheal intubation Endotracheal intubation with a cuffed endotracheal tube is required for any dental procedure. Sedation   Sedation or sedative protocol may be used for quick diagnostic procedures (ie radiographic examination).
  • Many patients in veterinary dentistry are older and/or have compromised core body functions. It is important to choose an anesthetic regimen that will provide these animals with the least risk and offer adequate analgesia Analgesia: overview intraoperatively and postoperatively. Regional anesthesia Local anesthesia: intravenous regional anesthesia (IVRA) is an excellent adjunct to general inhalation anesthesia because it will:
    • Allow the anesthetist to reduce systemic anesthesia levels (and risks) while providing appropriate intraoperative analgesia.   
    •  Aid in hemostasis and prolong analgesia when combined with specific drugs (eg dilute epinephrine 1:100,000). 
      Caution in hyperthyroidism or cardiac disease.
    • Provide long lasting postoperative analgesia when long acting solutions are used (ie bupivacaine Bupivacaine).
  • Despite some reports indicating that animals are more at risk for self-trauma to the locally anesthetized area during recovery from general anesthesia, this is not a typical response. Self-trauma occurs only when a block is made with excessive volume of drug or lack of attention to specific anatomical landmarks.

Body systems

  • The trigeminal nerve (CN5), and in particular its mandibular and maxillary branches, provides most of the innervation to the oral cavity in the dog and cat. The maxillary nerve at the rostral third of the pterygoid fossa gives off into the sphenopalantine nerve, later becoming the major palatine nerve. The maxillary nerve then enters the infraorbital canal and becomes the infraorbital nerve which provides innervation to the rostral teeth and gingiva, skin of the upper lips and nose. The mandibular nerve enters the mandibular  foramen on the medial aspect of the mandible and runs into the mandibular canal as inferior alveolar nerve, which innervates all mandibular teeth.

Dosage

  • Bupivacaine Bupivacaine:
    • Cats = 2 mg/kg (caution never exceed as a total dosage)  
    • Dogs = 2 mg/kg.
  • Syringe and 22 - 25 gauge x ¾ to 3 inch hypodermic needle.
  • Bupivacaine will take affect within 4-8 mins and will last 6-10 hours. The duration of anesthesia/analgesia may be increased, potentially doubled, with the addition of opioids such as morphine Morphine or buprenorphine Buprenorphine, as described in the brachial plexus block in humans. 

Technique

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Medical, financial and environmental benefits

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Beckman B W, Legendre L (2002) Regional nerve blocks for oral surgery in companion animals. Comp Cont Ed Prac Vet 24 (6), 439-442 VetMedResource.
  • Candido K D, Winnie A P, Ghaleb A H et al (2002) Buprenorphine added to the local anesthetic for axillary brachial plexus block prolongs postoperative analgesia. Reg Anesth Pain Med 27 (2), 162-167 PubMed.
  • Bazin J E, Massoni C, Bruelle P et al (1997) The addition of opioids to local anaesthetics in brachial plexus block: the comparative effects of morphine, buprenorphine and sufentanil. Anaesthesia 52 (9), 858-862 PubMed.

Other sources of information

  • Rochette J (2001) Local Anesthetic Nerve Blocks and Oral Analgesia. In: Proceedings from the 26th World Congress of the World Small Animal Veterinary Association, August 2001, pp 250-252.
  • Haws I J (1999) Local Dental Anesthesia. In:  Proceedings from the Thirteenth Annual Veterinary Dental Forum, October 1999, pp 304-307.
  • Holmstrom S E, Frost P, Eisner E R (1998) Veterinary Dental techniques. Philadelphia, W.B. Saunders, pp 492-493.


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