Combination of lidocaine gel and povidone–iodine to decrease acquired infections in procedures performed using topical anesthesia

In Brief Purpose: To test the antiseptic efficacy of povidone–iodine when mixed with topical lidocaine gel. Setting: Emory School of Medicine, Atlanta, Georgia, USA. Design: Experimental study. Methods: Staphylococcus epidermidis, Staphylococcus aureus, viridans streptococci (Streptococcus sanguinis), Escherichia coli, and Pseudomonas aeruginosa were grown on blood agar plates with povidone–iodine and/or lidocaine gel. The efficacy of sterilization was quantified by surviving bacterial colony-forming units. Results: Combination of povidone–iodine and lidocaine gel prevented bacterial growth to levels similar to povidone–iodine alone. Application of lidocaine gel to bacteria before povidone–iodine treatment allowed bacterial growth similar to controls not exposed to povidone–iodine. Conclusions: Povidone–iodine must be applied before lidocaine gel for effective antisepsis, but admixture of povidone–iodine with lidocaine gel was also effective and may reduce the risk of endophthalmitis associated with lidocaine gel use. This strategy offers a practice-changing alternative for preoperative prophylaxis in procedures requiring topical anesthesia. Mixing povidone–iodine with lidocaine gel kills bacteria similar to povidone–iodine alone, which might reduce the risk of endophthalmitis associated with lidocaine gel in cataract surgery and intravitreal injection.