Evaluation of the Sterility of a Vapocoolant Spray for Use in Minor Surgery

Vapocoolant sprays (skin refrigerants) are topical agents frequently utilized in a clinical office setting to reduce pain caused by needle injections or minor surgical procedures by rapid cooling of the skin. However, possible flammability and bacterial contamination have limited their use in clinics. The recent introduction of a non-flammable vapocoolant spray, "Pain Ease®" (Gebauer Co., Cleveland, OH), composed of 1,1,1,3.3-Pentafluoropropane and 1,1,1,2-Tetrafluoroethane, has been suggested as a possible alternative product. The purpose of this study is to evaluate the sterility of Pain Ease® and to determine whether this product is suitable for use prior to small skin incisions or injections such as botulinum toxin. A prospective, blinded, and controlled study was performed on 50 healthy adult volunteers. From each subject, three swab cultures were obtained from the same cheek area: (1) at time 0 prior to any skin preparation (control), (2) after antiseptic preparation with 70% isopropyl alcohol swabs, and (3) after spraying with Pain Ease®. All microbiology specimens were quantitatively and qualitatively analyzed for five days in a blinded fashion regarding the nature and sequence of the culture swabs, and gram stains were obtained when cultures were positive. Three samples of Pain Ease® alone were also cultured to further investigate the microbiologic activity of the product. No injections or surgical procedures were carried out in this study. Bacterial growth was found in 98% of cultures taken before antiseptic was applied (group I), in 54% of cultures after alcohol was applied, and in 46% of cultures after spraying with vapocoolant. There was statistically significant difference found between group I (no antiseptic) and both group II (after antiseptic but before vapocoolant) and group III (after vapocoolant) (p < 0.001), but not between groups 2 and 3 (p = 0.74). The pathogens most commonly cultured were gram positive cocci and gram positive bacilli. No positive cultures were observed in samples containing only Pain Ease®. The widely used and cost-effective topical antiseptic 70% isopropyl alcohol significantly reduces skin colonization when compared to unprepared skin (p < 0.001). When Pain Ease® is sprayed on skin prepared with alcohol, there is no statistically significant increase in bacterial colonization than when alcohol is used alone. We present prospective, blinded data using a mock injection clinical model suggesting the use of Pain Ease® as an inexpensive and safe product in clinics from a microbiologic standpoint.