Barrier protection capacity of flip-top pharmaceutical vials.

Study Objective: To test the sterility of medication vial tops after removal of the dust cover, and to survey anesthesia providers for their perceptions surrounding medication vials and sterility.

Design: Experimental design and survey instrument.

Setting: Ambulatory and hospital care setting.

Participants: Anesthesia providers in the United States.

Measurements: A two-question survey was distributed to anesthesia providers in the U.S. An experimental model was conducted on a total of 42 medication vials. The access diaphragms of medication vials were sampled after routine handling, after exposure to aerosolized contamination with the dust cover on, and after submersion into a bacterial medium with the dust cover on.

Main Results: 878 responses to Question 1 and 876 responses to Question 2 were received. Fifty-two percent of respondents declared that the access diaphragm was sterile in routine conditions, and 43% felt that (or were unsure if) the dust cover would prevent contamination when exposed to a contaminated environment. Two of the 12 vials sampled in the routine handling model had microbial contaminants on the access diaphragm. No growth was found on any of the 15 vials exposed to aerosolized E. coli. Seven of the 15 vials in the submersion model were contaminated.

Conclusions: Anesthesia providers in the U.S. possess contradictory opinions of, and unclear knowledge about, the sterility of rubber stoppers used to access medications, and also the barrier capacity of a vial's dust cover. Standard anesthetic medication vial dust covers do not offer barrier protection against the growth of pathogens.