Local Anesthetics and Loco-Regional Techniques

Local anesthetics are low-cost, nonscheduled drugs that are widely used for treatment of perioperative pain, and to reduce inhalant and injectable anesthetic requirements. Local anesthetics inhibit the generation and propagation of electrical impulses in a reversible manner by blocking sodium (Na+) channels. There are several factors that determine the onset and duration of action of a local anesthetic. Complications and toxicity may occur if doses and contraindications are not considered. Knowledge of anatomy and clinical pharmacology is essential for effective use of loco-regional techniques in the clinical setting. These techniques can be used to produce anesthesia at many sites. This chapter describes local anesthetics and loco-regional techniques in the cat.