Is it safe to re-access sodium bicarbonate bottles for use in minor surgery?

BACKGROUND/PURPOSE:Sodium bicarbonate is added to lidocaine to reduce injection pain. In Canada, it is available in vials exceeding the injection volume 100-fold. These are single-use vials that should be disposed of after one access. Some surgeons re-use vials to reduce waste, potentially causing contamination. This study aims to review the safety of sodium bicarbonate and assess alternatives to current practice. METHODS:Strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Burkholderia cepacia were used to assess bacterial growth in vials of sodium bicarbonate. Each pathogen was inoculated into a vial for 14 days at room temperature. At several time points, 1 mL of solution was removed and diluted. One hundred microliters were transferred to blood agar plates and incubated at 35 °C. Colony counts were calculated, averaged and plotted onto a logarithmic graph. RESULTS:Colony counts of all strains fell below observational threshold after 7 days in sodium bicarbonate. CONCLUSIONS:Although all strains were reduced, bacteria can survive in sodium bicarbonate for several days, during which transmission may occur. Sodium bicarbonate vials should be treated as single-dose, as indicated by the manufacturers. To reduce waste, hospital pharmacies can repackage sodium bicarbonate into smaller vials or pre-alkalize lidocaine with sodium bicarbonate.