The Effect of Commonly Used Local Anesthetic on Bacterial Growth

• Published in: The Journal of surgical research Vol. 274; pp. 16 - 22
• Main Authors: Callahan, Zachary M., Roberts, Amity L., Christopher, Adrienne N., Gadomski, Stephen P., Kuchta, Kristine M., Costanzo, Caitlyn M., Phillips, Benjamin R., Isenberg, Gerald A., Goldstein, Scott D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-06-2022
• Subjects: Anesthesia, Local; Anesthetics, Local - pharmacology; Antimicrobial; Bupivacaine; Bupivacaine - pharmacology; Escherichia coli; Humans; Lidocaine - pharmacology; Liposome; Local anesthetic; Pain, Postoperative; Staphylococcus aureus; Surgical site infection; Antimicrobial; Local anesthetic; Liposome; Surgical site infection; Bupivacaine
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1016/j.jss.2021.12.040

Liposomal bupivacaine (LB) has emerged as a superior form of local anesthetic across numerous surgical subspecialties. The purpose of this study is to evaluate the ex-vivo antimicrobial effects of LB in comparison with traditional local anesthetics.
A standardized inoculum of bacteria commonly associated with surgical site infection was inoculated into a suspension of 1% lidocaine, 0.25% bupivacaine, Exparel (proprietary liposomally packaged 1.3% bupivacaine), and normal saline as a growth control.
In all five bacteria tested, the medium inoculated with traditional local anesthetics reduced growth to a greater degree than LB-inoculated plates. Both conventional local anesthetics reduced the growth of all bacteria when compared with the control with the exception of methicillin-susceptible Staphylococcus aureus growth in bupivacaine. LB-inoculated plates had equivalent growth to the control in all plates with the exception of Escherichia coli plates which demonstrated superior growth.
The results of this simple ex-vivo model suggest that the liposomal packaging of bupivacaine may decrease this local anesthetic's innate antibacterial properties.
•The ex-vivo growth of bacteria is affected by exposure to local anesthetics.•Both bupivacaine and lidocaine reduced the growth of bacteria compared with control.•Liposomally packaged bupivacaine did not reduce the growth of any bacteria.•In vivo studies are required to further investigate this discrepancy.