gms | German Medical Science

Introduction: Surgery is very demanding in the field of esthetic operations. Scars, result of poor skills or because of an infection, are not desired. Among other things, reprocessing of surgical instruments is an often neglected issue. Function and hygiene of medical devices require adequate reprocessing procedures including washer disinfector, validation and quality management. Sterilization is a single-most important step at the end of the whole reprocessing cycle including transport, pre-cleaning, automated cleaning, maintenance, function control, packaging, and then sterilization by means of steam, peroxy acide or formaldehyde. Finally, after commissioning the surgical staff is going to reuse the medical devices on the next patient. Reuse of single-use devices means that liability passes over to the hospital and surgeon. But also some reusable instruments are better not reused like suction cannulas for liposuction or other needle-like instruments. Cleaning is crucial for any surface structure enabling the safe function of gliding parts. Rinsing, dismantling or opening of shafts therefore is required to assure cleanliness as important feature for mechanical function and prevention of infection. Medical devices are an expensive investment that is often neglected which may cause damage.

Materials and methods: In a prospective cohort study 6 different instrument designs underwent clinical investigation concerning cleanliness after the cleaning step in the washer disinfector without the thermal disinfection, without sterilization as well, to detect remainig proteinacious material that was then rinsed from the instrument surfaces. Six samples each were used. Six german hospitals colaborated for the study. The solution (5 ml eluate) then was tested for protein traces with 4 different methods (pseudoperoxydase reaction, modified Biuret, photometric OPA method, visual inspection). Remanents on the surfaces remained unknown as it was not possible to destroy the samples of the six hospitals involved.

Results: One to two out of three instruments showed traces of proteinacious material. The cohort was too small to differentiate between different instrument designs, different hospital sites, different methods of reprocessing or the impact of ultrasound used or not.

Discussion: Sterilization is necessary to minimize the risk of infection by transmission of microorganisms. Independant from different reprocessing behaviours and hospital sites – fact is that surfaces of medical devices tend to have proteinacious material that is rinsable by liquids like water or the human blood of the next patient. One to two out of three samples were tested positiv by different methods with more less sensitivity and specifity for the kind of proteins.

Conclusion: Patients must be aware that contact to surgeons means contact to infectious material that possibly can be transmitted by surgical medical devices which obviously does not lead to infections as known in the time before F. Nightingale was introducing sterilization by vapour.