BACKGROUND: Infections after epidural and spinal blocks are rare. The topical anesthetic liclocaine used in these procedures has been found to have antibacterial effects on various microorganisms. OBJECTIVE: The aim of this study was to assess the antibacterial effects of alkalinized liclocaine on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. METHODS: Lidocaine 2%, alkalinized lidocaine, and physiologic saline (as a control solution) were added to standard bacterial preparations. The final concentration of the lidocaine was 10 mg/mL (1%). At baseline and 3 and 6 hours after incubation at 37°C, 3-mL aliquots were vortexed and pipetted into sterile polystyrene spectrophotometer cuvettes. Baseline referred to the end of the period of preparation of the solution (≤20 minutes). Growth was measured as the optical density at a wavelength of 540 nm. RESULTS: Compared with the control, lidocaine significantly inhibited the growth of S aureus, E coli, and P aeruginosa at baseline and 3 and 6 hours after incubation (all, P < 0.05). Alkalinized lidocaine significantly inhibited the growth of S aureus at baseline and 3 and 6 hours (all, P < 0.05), while it significantly inhibited the growth of E coli and P aeruginosa only at 6 hours (both, P < 0.05). The growth of E coli was significantly less in lidocaine than in alkalinized lidocaine at 0 and 3 hours (both, P < 0.05). CONCLUSION: The antibacterial effect of lidocaine 1% on S aureus was not changed after alkalinization. The effect of alkalinized lidocaine on E coli and P aeruginosa was significant only at 6 hours. Lidocaine significantly inhibited the growth of these 3 microorganisms at all study periods.
BACKGROUND: Infections after epidural and spinal blocks are rare. The topical anesthetic liclocaine used in these procedures has been found to have antibacterial effects on various microorganisms. OBJECTIVE: The aim of this study was to assess the antibacterial effects of alkalinized liclocaine on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. METHODS:Lidocaine 2%, alkalinized lidocaine, and physiologic saline (as a control solution) were added to standard bacterial preparations. The final concentration of the lidocaine was 10 mg/mL (1%). At baseline and 3 and 6 hours after incubation at 37°C, 3-mL aliquots were vortexed and pipetted into sterile polystyrene spectrophotometer cuvettes. Baseline referred to the end of the period of preparation of the solution (≤20 minutes). Growth was measured as the optical density at a wavelength of 540 nm. RESULTS: Compared with the control, lidocaine significantly inhibited the growth of S aureus, E coli, and P aeruginosa at baseline and 3 and 6 hours after incubation (all, P < 0.05). Alkalinized lidocaine significantly inhibited the growth of S aureus at baseline and 3 and 6 hours (all, P < 0.05), while it significantly inhibited the growth of E coli and P aeruginosa only at 6 hours (both, P < 0.05). The growth of E coli was significantly less in lidocaine than in alkalinized lidocaine at 0 and 3 hours (both, P < 0.05). CONCLUSION: The antibacterial effect of lidocaine 1% on S aureus was not changed after alkalinization. The effect of alkalinized lidocaine on E coli and P aeruginosa was significant only at 6 hours. Lidocaine significantly inhibited the growth of these 3 microorganisms at all study periods.
Authors: M Curatolo; S Petersen-Felix; L Arendt-Nielsen; R Lauber; H Högström; P Scaramozzino; M Luginbühl; T J Sieber; A M Zbinden Journal: Anesth Analg Date: 1998-02 Impact factor: 5.108