Assessment of Multi-dose Lidocaine Vials use for Microbial Contamination in Ophthalmic Regional Anesthesia in Ocular Surgeries

Background: Lidocaine is a commonly used local anesthetic in various medical procedures, including ocular surgeries. However, there are important considerations when lidocaine is used in conjunction with microbial pathogens or in the presence of infection, particularly during ocular procedures. Microbial contamination could potentially increase the risk of endophthalmitis, a serious complication following eye surgery. The choice of anesthetic should not interfere with the effectiveness of antimicrobial agents used during surgery. It is essential to follow strict infection control practices, and should always be used in conjunction with proper antimicrobial treatment to reduce the risk of ocular infections. Objective: This study aimed to evaluate the risk of microbial contamination of multiple-dose lidocaine vials after opening, and the associated risk factors in ocular surgeries. Materials and methods: This study includes 360 lidocaine vials and 1 control multi-dose vials (MDV) from the same patch used in the assessment at the Research Institute of Ophthalmology's Ocular Operating Rooms between May and September 2024. Samples were taken from MDV Lidocaine under sterile precaution and underwent microbial analysis to inspect bacterial contamination related. Results: A total number of 9 vials containing microorganisms were identified from the 360 administered lidocaine solution vials used in the microbiology investigation, the overall prevalence of contamination was 2.5%. Gram negative bacteria were more common than Gram positive bacteria and no mixed contamination was found in any of the MDVs, microbial species were identified from the total number of bacterial isolates as follows: 2 (37%) and 7 (63%) of the contaminations were caused by Gram-positive and Gram-negative bacteria respectively. P. aeruginosa and K. pneumoniae were the most prevalent Gram-negative bacteria and accounts for 5 (71.4%) and 2 (28.6%) isolates respectively. The only Gram positive bacteria that were isolated were coagulase negative staphylococci (CoNS). Conclusion: The demonstrated data in this study showed the possible risk of microbial contamination after opening and repeatedly using the lidocaine multidose vials. Adhering to aseptic protocols can minimize the risk of infection and ensure optimal outcomes for the patient.