9 Oral Pain Management

INDICATIONS



  • To control oral pain preoperatively, perioperatively, and postoperatively by focal and/or systemic routes using multimodal therapy

c09uf003EQUIPMENT: MATERIALS


Injectable Opioids and Alpha-2 Agonists



  • Buprenorphine
  • Butorphanol
  • Hydromorphone
  • Morphine
  • Oxymorphone
  • Fentanyl
  • Methadone
  • Dexmedetomidine
  • Xylazine

Local Anesthetics



  • Bupivicaine, 0.5%
  • 1-cc syringe
  • 25–27-gauge, 1–3-in. hypodermic needles
  • Dosage: cats and small dogs = 0.1 cc; medium dogs = 0.2 cc; large dogs = 0.3 cc
  • Add buprenorphine (to double duration) at 3 µm/kg in same syringe1

Injectable Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)



  • Carprofen
  • Meloxicam

Oral or Transmucosal Opioids



  • Buprenorphine
  • Methadone
  • MS Contin (time-released formulation of morphine sulfate)

Oral NSAIDs



  • Carprofen
  • Meloxicam
  • Other veterinary-labeled NSAIDs

MECHANISM OF LOCAL ANESTHETICS



  • Inhibit sodium (Na) cations’ passage through ion-selective Na+ channels in nerve membranes by selectively binding these channels and thereby preventing nerve impulse transmission1

METHODS


Sites and Means for Control of Pain



  • Local anesthesia agents and alpha-2 agonists will inhibit transduction at A-delta and C nocioceptors and transmission of pain to the spinal cord
  • Anti-inflammatory drugs are known to act both peripherally at the site of inflammation and centrally to modulate spinal transmission
  • Opioids can modulate pain centrally and locally
  • N-Methyl-D-aspartic (NMDA) antagonists, such as ketamine,2 can greatly decrease central sensitization

c09uf004PROCEDURE FOR REGIONAL ANESTHESIA


Anatomical Sites for Local Anesthetic Infusion3



  • Maxilla: at the pterygopalatine branch of the maxillary nerve (an extension of the trigeminal nerve) as it courses through the pterygoid fossa ventral to the junction of the rostral/middle one-third of the zygomatic arch

    • Access via the infraorbital foramen (Fig. 9-1)
    • Premeasure hypodermic needle length from the infraorbital foramen to the junction of the rostral/middle one-third of the zygomatic arch (Fig. 9-2)
    • Insert hypodermic needle slowly into the infraorbital foramen, extending caudally to the level of the pterygopalatine nerve branch
    • Aspirate, rotate needle 90 degrees and aspirate, repeating the process to complete 360 degrees, infuse slightly, aspirate again; if no backflash of blood enters the syringe, infuse desired volume slowly
    • Gently remove hypodermic needle and hold pressure on the injection site for 1 minute to avoid hematoma formation
    • Regional anesthesia will affect the oral tissue from the point of injection to the midline and rostral, including the hard palate

  • Mandible: at the entrance of the inferior mandibuloalveolar branch of the mandibular nerve (an extension of the trigeminal nerve) into the mandibular foramen

    • Access the site by inserting the hypodermic needle medial to the ramus, caudal to the third molar tooth coursing caudally toward the angular process of the mandible; to establish a target, place a finger extraorally on the angular process and direct the needle toward and just short of your finger (Fig. 9-3)
    • An alternate access is to imagine a line extending ventral from the lateral canthus of the eye; enter via the skin medial to the ventral cortex of the mandible coursing dorsally to a point approximately half the width of the body of the mandible4
    • Aspirate and rotate the syringe as described above
    • Infuse slowly and withdraw the needle; hold pressure as described above to prevent hematoma formation
    • The mandibular tissues will be anesthetized from the point of injection site rostral to the midline and medial to but not affecting the tongue

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May 22, 2017 | Posted by in GENERAL | Comments Off on 9 Oral Pain Management

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