Analysis of possible cross-contamination with the Venturi system atomizer

The physics behind the Venturi atomizers suggest a possibility of bacterial colonization and the potential for patient cross-contamination. A protocol for use of the atomizer and clinically appropriate demonstration of cross contamination has not been established.

Three sterilized atomizers filled with a solution of 2% Pontocaine and 1% ephedrine (two test and one control) were used during a 5-day study period. Clinic staff was instructed to (1) use a nozzle tip, (2) use a nasal speculum, (3) avoid contact between the atomizer and the patient, and (4) apply a continuous, <1-second spray to the nasal cavity. Samples were obtained from each of the atomizers three times per day and plated on chocolate agar plates. The number and type of bacterial colony were registered.

No respiratory pathogens grew from any of the 45 plated samples. Nine of 30 experimental atomizer samples produced 12 bacterial colonies. Of the 12 bacterial colonies obtained, 6 colonies of coagulase-negative Staphylococcus, 5 colonies of Corynebacterium sp., and 1 colony of Bacillus sp. were identified. One of 15 plated control atomizer samples produced two colonies of coagulase-negative Staphylococcus. An average of 1.3 colonies per positive test plate and an average of 2.0 colonies per positive control plate were identified. There was no evidence of an increasing number of colonies per plate or persistence of any particular bacteria identified over time to suggest contamination or colonization of the system reservoir.

There is no risk of cross-contamination of patients with the use of the Venturi system atomizer as outlined in this study. Culture results from this study were consistent with random culture contamination during the plating and/or culturing period. There was no evidence to support the idea of bacterial colonization of the atomizers. Continued use of the Venturi system atomizer is an acceptable practice.