Effect of lidocaine gel on povidone-iodine antisepsis and microbial survival.
OBJECTIVE
To determine whether the use of lidocaine gel prior to povidone-iodine antisepsis is associated with increased microbial survival.


METHODS
Ophthalmology Department, Madigan Army Medical Center, Fort Lewis, Washington, USA.


METHODS
A standardized suspension of Staphylococcus epidermidis was used to inoculate 5 blood agar plates that served as a control. A second group of 5 blood agar plates was inoculated, and then lidocaine gel was applied to the plates. A third group of 5 blood agar plates was inoculated, lidocaine gel was applied, and then povidone-iodine 5% was applied and allowed to cover the plates. A fourth group of 5 blood agar plates was inoculated, and then povidone-iodine 5% was allowed to cover the plates. Cultures of Staphylococcus aureus, Pseudomonas aeruginosa, and Haemophilus influenza were tested in a similar fashion. Microbial growth was evaluated after 24 hours.


RESULTS
The number of colony forming units (CFUs) was similar in the control group and the S epidermidis, S aureus, and P aeruginosa lidocaine only and lidocaine with povidone-iodine groups. In these groups, each plate grew between 200 CFUs and 300 CFUs. In the Haemophilus influenza series, the lidocaine with povidone-iodine group had fewer CFUs than the control group. In all 4 series, the povidone-iodine only group had the least amount of CFUs, ranging from 0 to 6.


CONCLUSIONS
The use of lidocaine gel before application of povidone-iodine 5% resulted in decreased effectiveness of antisepsis and increased microbial survivability. The increase in microbial survivability may increase the risk for postoperative infection in ocular surgery performed under topical anesthesia.
Boden
John H
JH
Department of Ophthalmology, Madigan Army Medical Center, Tacoma, Washington 98431, USA. john.boden@amedd.army.mil
Myers
Mary L
ML
Lee
Thomas
T
Bushley
D Matthew
DM
Torres
Mark F
MF
D000779:Anesthetics, Local / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001419:Bacteria / Q000254:growth & development*; D015169:Colony Count, Microbial; D005782:Gels / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000254:growth & development; D008012:Lidocaine / Q000494:pharmacology*; D011206:Povidone-Iodine / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000235:genetics; D013211:Staphylococcus aureus / Q000254:growth & development; D013212:Staphylococcus epidermidis / Q000254:growth & development
D000779:Anesthetics, Local; D000891:Anti-Infective Agents, Local; D005782:Gels; D011206:Povidone-Iodine; D008012:Lidocaine