Local anesthetics can effectively prevent the transduction and transmission of pain and may be the only way to completely block perioperative pain. Methods of providing local anesthesia include wound or tissue infiltration, regional nerve blocks, neuraxial analgesia (eg, intrathecal, epidural), and placement of soaker catheters. The short duration of action of available formulations of local anesthetics is the significant limiting factor. Fenestrated wound catheters with intermittent local anesthetic administration can extend the duration of analgesia of local anesthetics but are only useful in hospitalized patients.
The FDA recently approved a bupivacaine liposomal injectable suspension that is estimated to be efficacious for 72 hours post- intraoperative tissue infiltration following cruciate surgery in dogs. Liposomes are microscopic structures composed of lipid bilayers, which gradually break down to release their contents over 96 hours. A moving-needle technique is used to inject the solution into all tissue layers in the surgical field. Bupivacaine is gradually released into local tissues and then into systemic circulation.
The author concluded that this product may be an effective and beneficial tool for post-operative pain management.—Lascelles BDX
The research referenced includes a study funded by Aratana Therapeutics.