Dayane de Melo Costa1, Lillian Kelly de Oliveira Lopes2, Anaclara Ferreira Veiga Tipple3, Khalid Johani4, Honghua Hu2, Anand Kumar Deva2, Evandro Watanabe5, Karen Vickery6. 1. Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia; Faculty of Nursing, Federal University of Goias, Goiania, Brazil. 2. Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia. 3. Faculty of Nursing, Federal University of Goias, Goiania, Brazil. 4. Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia; Central Military Laboratories and Blood Bank, Prince Sultan Military Medical City, Riyadh, Saudi Arabia. 5. School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirao Preto, Brazil. 6. Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia. Electronic address: karen.vickery@mq.edu.au.
Abstract
BACKGROUND: To determine the effect of multiple use and processing cycles on instrument quality over the life of stainless steel, complex designed clinical surgical instruments. METHODS: Steam sterilised surgical instruments due to be discarded from Australian hospitals, because of loss of functionality, were assessed for contaminating protein and bacteria using the bicinchoninic acid protein assay and microbial culture, respectively. Biofilm presence and instrument damage were visually confirmed by scanning electron microscopy (SEM). Instruments were categorised into hinged/serrated, screw, cannulated, flexible, and irregular surfaced (but not hinged) according to their design. RESULTS: Protein contamination ranged from 24 μg on the new screw to 3,756,046 μg contaminating a discarded forceps. The more complex the instrument design the higher the protein contamination. All samples were culture negative, however, biofilm was visually confirmed on 4/8 instruments tested using SEM. SEM also detected soil, holes or black stains on all the instruments. CONCLUSION: "Ready to use" surgical instruments that underwent multiple uses and processing cycles were contaminated with high amounts of protein, and microscopy revealed the presence of soil, structural damage, black stains and biofilm. While less affected new but multiply processed screws also showed soil and biofilm contamination. These findings highlight the need for further research into determining what is the "life" of stainless steel instruments and development of standard criteria for evaluating when to "retire" an instrument.
BACKGROUND: To determine the effect of multiple use and processing cycles on instrument quality over the life of stainless steel, complex designed clinical surgical instruments. METHODS: Steam sterilised surgical instruments due to be discarded from Australian hospitals, because of loss of functionality, were assessed for contaminating protein and bacteria using the bicinchoninic acid protein assay and microbial culture, respectively. Biofilm presence and instrument damage were visually confirmed by scanning electron microscopy (SEM). Instruments were categorised into hinged/serrated, screw, cannulated, flexible, and irregular surfaced (but not hinged) according to their design. RESULTS: Protein contamination ranged from 24 μg on the new screw to 3,756,046 μg contaminating a discarded forceps. The more complex the instrument design the higher the protein contamination. All samples were culture negative, however, biofilm was visually confirmed on 4/8 instruments tested using SEM. SEM also detected soil, holes or black stains on all the instruments. CONCLUSION: "Ready to use" surgical instruments that underwent multiple uses and processing cycles were contaminated with high amounts of protein, and microscopy revealed the presence of soil, structural damage, black stains and biofilm. While less affected new but multiply processed screws also showed soil and biofilm contamination. These findings highlight the need for further research into determining what is the "life" of stainless steel instruments and development of standard criteria for evaluating when to "retire" an instrument.