Case description: A 5-year-old castrated male domestic shorthair cat was examined because of presumptive lidocaine intoxication. Thirty minutes earlier, the cat had received an SC injection of approximately 140 mg of lidocaine hydrochloride (20 mg/kg [9.1 mg/lb]) to facilitate closure of a wound on the left pelvic limb.
Clinical findings: Initial physical examination revealed severe lethargy and respiratory distress; erratic, poor-quality pulses with severe hypotension; and pulmonary edema.
Treatment and outcome: Initial supportive treatment included administration of oxygen and IV administration of lactated Ringer's solution. Additional treatment with a 20% lipid emulsion (1.5 mL/kg [0.68 mL/lb], IV) delivered over a 30-minute period resulted in dramatic improvement in cardiovascular and behavioral variables. No adverse effects from lipid emulsion were detected on routine hematologic evaluation, thoracic radiography, or computed tomography.
Clinical relevance: IV administration of a lipid emulsion was used in the treatment of lidocaine intoxication in a cat. Rapid infusion of a lipid emulsion may be a therapeutic option for veterinary patients with toxicosis attributable to local anesthetics or other lipid-soluble drugs.