Clinical Evaluation of a Liquid Chemical Sterilization System for the Flexible Bronchoscope

Abstract

A growing number of immunocompromised patients are undergoing both diagnostic and therapeutic flexible bronchoscopy (FFB). Despite written policies and recommendations for high-level disinfection and sterilization, a number of infections transmitted by contaminated FFB have been reported. The purpose of this study was to analyze prospectively our department's cleaning and sterilization protocols. The sterilization procedure utilizes a liquid chemical sterilization process using peracetic acid as the active biocidal agent. We prospectively studied 20 consecutive patients suspected to have a lower respiratory tract infection who underwent a FFB procedure with bronchoalveolar lavage (BAL) and protected specimen brush (PSB) specimen collections. Sterile normal saline (NS) was aseptically suctioned and collected through the bronchoscope's suction channel after the procedure (preprocessing fluid). The scope was then cleaned and processed in a liquid chemical sterilization system. After processing, sterile NS was suctioned and collected (postprocessing fluid) in a similar fashion. Cultures of the BAL and PSB, preprocessing, and postprocessing fluids were compared. In addition to the 20 patients studied, deliberate inoculations of the FFB with Mycobacterium avium complex (MAC) organisms were done. Cultures of the inoculated, preprocessing, and postprocessing fluids were compared. BAL cultures and PSB cultures revealed growth in 14 and in 15 of 20 patients, respectively. Pneumocystis carinii was noted in three patients. Viral cultures were positive for cytomegalovirus in three patients and positive for herpes simplex virus in one patient. All postprocessing fluid cultures were negative except in two patients. In these two, the postprocessing fluid was positive for the presence of coagulase-negative staphylococci and diphtheroids. The rare number of these organisms isolated was felt most likely to represent contaminated collection or processing procedures in the laboratory. The postprocessing fluids of the inoculated bronchoscopes revealed no growth for MAC organisms. Our results indicate that our department's cleaning and sterilization protocol was effective in eradicating bacterial, mycobacterial, and viral organisms. The liquid chemical sterilization system utilizing peracetic acid as the active biocidal agent provided an effective and safe sterilization process with a relatively quick turnover time.