Drug Contamination from Opening Glass Ampules

Recently there have been several reports of postoperative sepsis due to the intravenous injection of contaminated solutions of propofol (Diprivan). The mechanism by which this contamination occurred has not been identified. This study sought to determine whether bacterial contamination of the contents of glass ampules can be decreased by swabbing the neck of the vial with alcohol prior to opening. Glass ampules of 1% propofol and 1% lidocaine were swabbed with a solution of Staphylococcus epidermidis. Half of these ampules were subsequently wiped with alcohol pads prior to being opened. An aliquot from each ampule was pipetted into a nutrient broth and allowed to incubate overnight at 37 degrees C. These solutions were plated on agar, incubated for 24 h, and then examined for bacterial growth. Three of the eight lidocaine ampules and six of the eight propofol ampules not cleaned with alcohol demonstrated evidence of bacterial contamination. The contents of all ampules that had been wiped with alcohol prior to being opened remained sterile (P less than 0.001 vs. non-alcohol-treated group for propofol ampules and P = 0.20 vs. non-alcohol-treated group for lidocaine ampules). These data suggest that bacterial contamination of propofol and lidocaine may occur as a result of opening glass ampules. Wiping the outside of the ampule with alcohol immediately prior to opening may decrease this risk.