Page 2276 - Cote clinical veterinary advisor dogs and cats 4th

1130 Local and Regional Anesthesia

○ Animal is usually sedated or under general • Peripheral nerve blocks
anesthesia. ○ Dental nerve block: self-mutilation after
VetBooks.ir Other regional techniques: ○ Brachial plexus block: inadvertent IV
• Epidural anesthesia/analgesia
sensory loss to tongue and lips (rare)
or intraarterial injection or injection
• Intraarticular anesthesia/analgesia
○ Hypodermic needle (22 gauge), syringe,
sterile gloves, local anesthetic (lidocaine, into the thoracic cavity with possible
pneumothorax/pulmonary laceration
bupivacaine) ± opioid (morphine) ○ Distal radial, ulnar, median nerve blocks:
○ Animal is usually sedated or under general self-mutilation after sensory loss to distal
anesthesia. paws (rare)
• Interpleural anesthesia ○ Intercostal nerve block: inadvertent
○ Butterfly catheter (22 gauge) or through- intrathoracic injection with possible
the-needle catheter (20 gauge, 2 inches); pneumothorax/pulmonary laceration
preplaced chest tube or commercial • Other regional techniques
interpleural anesthesia tray, syringe, sterile ○ Intraarticular anesthesia/analgesia: articular
gloves, local anesthetic cartilage damage
○ Dosages: lidocaine ≤ 5 mg/kg (dog) q ○ Interpleural anesthesia: pneumothorax,
2-4h; ≤ 3 mg/kg (cat) q 4h; bupivacaine pulmonary laceration
≤ 2 mg/kg (dog) initially, then ≤ 1 mg/ ○ IV regional anesthesia: ischemic limb
kg q 6h; ≤ 1 mg/kg (cat) initially, then damage; systemic local anesthetic toxicosis LOCAL AND REGIONAL ANESTHESIA Brachial
≤ 0.5 mg/kg q 6h. due to tourniquet failure plexus nerve block. Place needle medial to scapu-
○ Animals are usually sedated or under lohumeral joint, lateral to thoracic wall, toward
general anesthesia. Procedure costochondral junction, parallel to vertebral column.
• IV regional anesthesia For selected techniques only (From Fossum TW, et al: Small animal surgery, ed 2,
○ Cling-and-release bandage material • Peripheral nerve blocks St. Louis, 2002, Mosby.)
(e.g., Vetrap), IV catheter (22 gauge), ○ Dental nerve blocks
tourniquet, hypodermic needle (22 gauge), ■ Infraorbital: palpate infraorbital foramen
syringe, local anesthetic (lidocaine) rostral and ventral to medial canthus
○ Dose: lidocaine 2.5-5 mg/kg (dog only) of eye; insert needle into foramen and
○ Animal is usually sedated. aspirate. If there is negative pressure ■ Insert catheter in the ninth intercostal
(no blood), inject local anesthetic. space on the midlateral aspect of thorax.
Anticipated Time ■ Mandibular: palpate mandibular fora- ■ Aspirate to remove air/blood.
This time does not include clipping of hair men intraorally on the medial surface of ■ Inject local anesthetic (lidocaine should
and preparation of the site where indicated. the mandible, and insert needle percu- be injected first in conscious animals to
• Infiltrative anesthesia taneously from the ventromedial aspect minimize discomfort and can be fol-
○ Incisional block: < 1-2 minutes of the mandible toward the foramen lowed by bupivacaine if a long-duration
• Peripheral nerve blocks and aspirate. If there is negative pressure block is desired).
○ Dental nerve blocks: < 1-2 minutes (no blood), inject local anesthetic.
○ Brachial plexus block: < 5-10 minutes ○ Brachial plexus block Postprocedure
○ Distal radial, ulnar, median nerve blocks: ■ From a cranial approach, insert the • If local/regional anesthesia is being used for
< 1-2 minutes needle medial to the scapula just supplementing analgesia in conjunction with
○ Intercostal nerve blocks: < 1-2 minutes ventral to the body of the sixth cervical general anesthesia, injectable and inhalation
• Other regional techniques vertebra; advance until the tip of the anesthetic requirements may be markedly
○ Intraarticular anesthesia/analgesia: < 1-2 needle is just beyond the first rib and reduced.
minutes aspirate. If there is negative pressure (no • Animals must be monitored for adequacy
○ Interpleural anesthesia: < 5-10 minutes blood), inject one-fourth dose of a local of analgesia and treated accordingly.
○ IV regional anesthesia: < 5-10 minutes anesthetic; withdraw needle partially,
and aspirate. If there is negative pressure Alternatives and Their
Preparation: Important (no blood), inject another one-fourth Relative Merits
Checkpoints dose of anesthetic; repeat until needle • Pain associated with surgery, trauma, and
• Ensure that injection site is clipped (if is completely withdrawn and all drug a variety of medical conditions can usually
applicable) and aseptically prepared. has been injected. be managed using systemic analgesics (e.g.,
• Adhere to strict aseptic technique during all ○ Distal radial, ulnar, median nerve blocks: opioids, nonsteroidal antiinflammatory drugs
procedures; doing this is mandatory. three injections required per paw [NSAIDs]); however, these agents are not
• Ensure that drug solutions are free from ■ On dorsal aspect, insert needle just able to block peripheral nociceptive input.
contamination (especially for epidural and proximal to the first phalanx and • The inclusion of a local or regional technique
intraarticular techniques). aspirate; if negative pressure (no blood), constitutes a multimodal approach to anes-
inject local anesthetic. thesia and pain management and is simply
Possible Complications and ■ On palmar aspect, insert needle just good medical practice.
Common Errors to Avoid medial to accessory carpal pad and
• Systemic local anesthetic toxicosis is possible aspirate; if negative pressure (no blood), SUGGESTED READING
with any technique and is usually associated inject local anesthetic. Campoy L, et al: Canine and feline local anesthetic
with inadvertent IV injection/excessive drug ■ Remove needle and insert just lateral and analgesic techniques. In Grimm KA et al,
doses. Calculate total dose per animal. and proximal to accessory carpal pad editors: Veterinary anesthesia and analgesia, ed 5,
• Infiltrative anesthesia and aspirate; if negative pressure (no Ames, IA, 2015, Wiley Blackwell, pp 827-856.
○ Incisional block: inadvertent IV or blood), inject local anesthetic. AUTHOR: Leigh A. Lamont, DVM, MS, DACVAA
intraarterial injection, penetration of body • Other regional techniques EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
cavities/organs ○ Interpleural anesthesia Thompson, DVM, DABVP

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