Microbial Contamination by a Medical Carbon Dioxide Laser

One of the advantages in using the carbon dioxide laser in medicine is the sterilization of the wound at the site of surgical intervention. In microbial studies, using the Sharplan Model 743 Medical Laser, we found substantial contamination of the area directly below the probe by viable bacteria and fungi. The levels of contamination varied from experiment to experiment, but were always substantial. The contamination is likely due to the stream of nitrogen gas emitted during and following laser irradiation in order to cool the lens. Following the implementation of several simple prophylactic procedures, including insertion of a filter on the end of the tube emitting the nitrogen gas, contamination by the gas stream was reduced to insignificant levels.