Study On The Current Situation Of Bacterial Endotoxin Contamination On The Surface Of Reused Surgical Instruments And The Factors Influencing The Removal Effect

Objective:To understand the current situation of bacterial endotoxin contamination on the surface of reused surgical instruments in hospital,and to study the effectiveness and influence factors of endotoxin removal in cleaning,disinfection and sterilization of reused surgical instruments.It provides the experimental data for the scientific establishment of the endotoxin ppm on the surface of reused surgical instruments and provides the basis for studying the method of removing endotoxin on the surface of the reused surgical instruments.Methods:Four third Class A hospitals in Beijing were selected to sample the surgical instruments during the procession recycling,cleaning,disinfection and sterilization.Two samples were collected at each time point in each hospital.Three surgical instruments for each sample were taken as a sample and divided into nocturnal groups(Emergency surgical instruments at night)and daytime group(Daytime surgical instruments);The instruments were put into the extraction solution for about 2-6 hours.Each sample was extracted and sent to the laboratory with 5 mL extract.The endotoxin content of the instrument was determined qualitatively and quantitatively by gel method and dynamic colorimetric method.Results:In this study,96 samples were collected,before cleaning,after cleaning,after disinfection and after sterilization,the four time points were 24.There were 64 samples in the daytime group,32 samples in the group with no obvious surface contamination and 32 samples in the group with obvious contamination.Noctumal group 32.Gel method:After four time points that before cleaning,after cleaning,after disinfection and after sterilization,the positive rates of endotoxin on the surface of the surgical instruments were 58.3%,37.5%,12.5%and 8.3%,respectively.The positive rate of the daytime group at four time points were 43.75%,31.25%,6.25%and 0,the nocturnal group positive rate at four time points were 88%,50%,25%and 25%,after sterilization was still positive samples from the nocturnal group,the positive rate of the nocturnal group at four time points were higher than that of daytime group.Dynamic chromogenic method:At the four time points before cleaning,after cleaning,after disinfection and after sterilization,the average of endotoxin on the surface of surgical instruments was 92.3EU/piece,26.5EU/piece,10.8EU/piece and 5.3 EU/piece,respectively.The highest bacterial endotoxin content was 882 EU/piece in 24 samples before cleaning.The highest bacterial endotoxin content in 24 samples after sterilization was 36 EU/piece.The average values of the daytime group at the four time points were 26EU/piece,16EU/piece,8EU/piece and 4 EU/piece,respectively,and the average values of the nocturnal group at the four time points were 226EU/piece,48EU/piece,18EU/piece and 10 EU/piece,respectively,After cleaning,after disinfection and after sterilizing the surgical instruments,the elimination rates of bacterial endotoxins were 71.3%,88.3%and 94.2%respectively.Statistical analysis shows that:The results of bacterial endotoxin on the surface of surgical instruments by gel method and dynamic coloration method were in good agreement.Nocturnal group(before cleaning)the content of bacterial endotoxin was higher than that of daytime group,and the difference was statistically significant.No matter whether there was obvious contamination on the surface of surgical instruments,there was no significant difference in bacterial endotoxin content The difference of bacterial endotoxin content in the surface of the apparatus from after recovery to after cleaning,after cleaning to disinfection was statistically significant,and there was no significant difference between the bacterial endotoxin content of the instrument surface after disinfection and sterilization.Conclusion:Reuse of surgical instruments(before cleaning)endotoxin pollution is serious,especially the surgical instruments which can not be dealt with in time.Cleaning and disinfection can effectively remove part of endotoxin,but can not be completely removed,there are still some surgical instruments after sterilization endotoxin residue;The effect of sterilization on the surface endotoxin of clear instruments was limited.The endotoxin contamination of surgical instruments after use is serious regardless of whether there are visible pollutants.It is suggested that all surgical instruments should be cleaned and disinfected in time.If it cannot be handled in time,it is recommended that dry and hot links be added after cleaning and disinfection,and then sterilization is carried out.Due to the different risk caused by endotoxin in different surgical instruments,it is suggested that the intrathoracic application and contact with cerebrospinal fluid should be treated separately,and dry and hot links should be added after cleaning and disinfection.