Assessment of Efficacy of Steam Sterilization for Assembled Laparoscopic Instruments- A Microbiological Study


Abhineet Mehrotra, Shivanshi Tiwari

BACKGROUND The most commonly used infection control methods are disinfection and sterilization. Disinfection technique helps to reduce the chances of contamination but is less effective to pathogenic organisms as compared to sterilization. Hence, we wanted to assess the safety of steam sterilization of the assembled laparoscopic instrument with test infection. METHODS Two different types of re-usable laparoscopic instruments were selected as test instruments; trocar and dissection forceps. Biological indicator used in the present study was Geobacillus stearothermophilus ATCC-7953 in sporulated form. For the present study, three study groups were defined: an experiment group, a negative control and a positive control. The assessed results gave a total of 1080 sampling units. Individual packing of the instruments in the surgical grade paper was done followed by autoclaving in the pressured saturated steam. Seeding of the biological indicator was done in Tryptic Soy Broth (TSB) culture medium, followed by incubation at 56o C for 21 days. The results were compiled in Microsoft Excel sheet and were analysed by SPSS software. RESULTS 100 percent satisfactory growth was seen in the positive controls which confirmed the test in the present research. This also confirmed the viability of the culture media along with adequate efficacy of the incubation condition for spore germination. CONCLUSIONS It is safe to use pressurized saturated steam sterilization for assembled laparoscopic instruments. However; further studies in this regard are recommended for better exploration of results.