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Local and Regional Anesthesia 1129

• Use the blunt probe placed into the instru- Closure: • Ultrasound-guided liver biopsy: less invasive,
ment portal to evaluate all lobes. • Open all cannulas, and expel CO 2 from may be performed using sedation, smaller
VetBooks.ir biopsy forceps into the instrument portal • Close port sites routinely in two- to three- Pearls
samples obtained
abdomen with gentle pressure on the
• Remove the blunt probe, and insert the
abdomen before removal of the cannulas.
to sample multiple liver lobes.
• Position the cup forceps on the margin of a
lobe, slowly twist the forceps and withdraw layer closure. • Poorly placed portals prevent adequate
visualization and access to the liver
to sever the liver sample, and remove through Postprocedure • A 30° scope improves visualization over a
the cannula. • The patient should be monitored for bleeding 0° scope.
• To sample the liver surface, open the forceps, by packed cell volume/total solids and blood • Biopsy abnormal- and normal-appearing
direct at a 90° angle to the surface, push into pressure. liver, and sample from at least two lobes.
the liver 5-1 0 mm, and close. • The patient may be monitored overnight
• Check all biopsy sites for excessive hemor- or discharged from the hospital the SUGGESTED READING
rhage; the blunt probe or gel foam may be same day. McDevitt HL, et al: Short-term clinical outcome
used for hemostasis. • An e-collar should be placed and the patient of laparoscopic liver biopsy in dogs: 106 cases
Gallbladder aspiration: activity level limited for 7-10 days. (2003-2013). J Am Vet Med Assoc 248:1, 2016. Procedures and Techniques
• Insert a 20-gauge, 2-3 inch spinal needle
using telescope guidance into the right Alternatives and Their RELATED CLIENT EDUCATION
ventrolateral abdomen, caudal to the last rib. Relative Merits SHEETS
• Direct the needle through the apex in an • Laparotomy: larger samples may be obtained,
avascular region of the gallbladder surface, a full exploration may be performed, and Consent to Perform General Anesthesia
and use a 3-5 mL syringe to aspirate as much therapeutic intervention such as liver lobec- Consent to Perform Hepatic (Liver) Biopsy
fluid as possible to prevent leakage. tomy may be performed when appropriate. AUTHOR: Jill K. Luther, DVM, MS, DACVS
• Fluid should be submitted for aerobic and Longer procedure times and more invasive EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
anaerobic bacterial culture. than laparotomy Thompson, DVM, DABVP

Local and Regional Anesthesia

Difficulty level: ♦ • Distal radial, ulnar, and median nerve May be diluted 1.1 with 0.9% sterile saline
blocks: supplemental analgesia for feline to increase injection volume for incisional
Synonym onychectomy or any surgical procedure infiltration
Local blocks involving the distal forepaw Infiltrative anesthesia:
• Intercostal nerve blocks: supplemental analge- • Incisional block
Overview and Goals sia after lateral thoracotomy or desensitizing ○ Hypodermic needle (22, 25 gauge),
• Local anesthesia and regional anesthesia refer area around isolated rib fractures syringe, sterile gloves, local anesthetic
to a broad range of techniques that use local Other regional techniques: ○ Animal is usually under general anesthesia,
anesthetic agents delivered to a discrete ana- • Intraarticular anesthesia/analgesia: supple- and block is done before incision is
tomic area (as opposed to systemic delivery). mental analgesia for procedures involving made or at the end of the surgery before
• With these techniques, the local anesthetic the joint space (stifle most common) complete closure.
agent inhibits pain by blocking transmission • Interpleural anesthesia: supplemental analge- Peripheral nerve blocks:
of noxious input (and other types of sensory sia for thoracic and cranial abdominal pain • Dental nerve block
input) before it ever reaches the brain. (especially pancreatitis) ○ Hypodermic needle (22, 25 gauge),
The animal’s level of consciousness is not • Intravenous (IV) regional anesthesia: syringe, local anesthetic
affected. desensitization of a distal limb to facilitate ○ Animal is usually under general anesthesia.
• This contrasts with general anesthesia, during surgery • Brachial plexus block
which nociceptive processing continues to ○ Hypodermic needle (22 gauge) or spinal
occur, but the animal is not able to perceive Contraindications needle (22 gauge, 2-3 inches [5-8 cm]),
pain because of the unconscious state. Infiltrative anesthesia, peripheral nerve blocks, syringe, local anesthetic
others: injection into infected tissue ○ Specialized insulated needle (22 gauge, 3
Indications inches) required if a nerve locator is to be
Infiltrative anesthesia: Equipment, Anesthesia used
• Incisional block: supplemental analgesia Local anesthetic agents: ○ Animal is usually sedated or under general
for a variety of surgical procedures (e.g., • Lidocaine: duration ≈1-3 h; total dose anesthesia.
abdominal wall incisions, total ear canal ≤ 5 mg/kg (dog); ≤ 3 mg/kg (cat) • Distal radial, ulnar, median nerve blocks
ablation incisions) • Bupivicaine: duration ≈3-4 h; total dose ○ Hypodermic needle (22, 25 gauge),
Peripheral nerve blocks: ≤ 2 mg/kg (dog); ≤ 2 mg/kg (cat) syringe, local anesthetic
• Dental nerve block: supplemental analgesia • Liposome encapsulated bupivacaine: ○ Animal is usually under general anes-
for tooth extractions, maxillary/mandibular gradual-release formulation with duration thesia, and block is done before surgical
surgeries ≈72 h; approved for use at incision site for procedure.
• Brachial plexus block: supplemental analgesia cruciate surgery (5.3 mg/kg [0.4 mL/kg] • Intercostal nerve block
for surgical procedures involving the forelimb dogs) and for onychectomy (5.3 mg/kg ○ Hypodermic needle (22, 25 gauge),
distal to shoulder per limb or 10.6 mg/kg [0.8 mL/kg] cats). syringe, local anesthetic

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