Disinfection of Surgical Instruments Using a Hydrodynamic System with Ozonated Water and Ultrasound: Preliminary Study.

Surgical site infections are the most common infections acquired at hospitals, with Staphylococcus aureus being the main agent due to its ability to adhere to surgical instruments. This study aimed to develop a hydrodynamic system associating ozonated water and ultrasound to disinfect surgical instruments. The equipment consists of a reservoir with sinuous internal geometry to accommodate instruments, from where ozonated water comes out and flows through the circuit with the aid of a pump. To assess its efficacy, microbiological evaluation was performed on scalpel handles experimentally contaminated with S. aureus. The hydrodynamic system promoted effective disinfection, obtaining 3-log of bacterial reduction with an applied ozone dosage of 3 mg O₃/cm² in seven minutes. The FEG-SEM images showed that the ultrasound (40 KHz, 50W) associated with the hydrodynamic circuit was sufficient to remove almost all bacteria adhered to the instrument´s surface, enabling ozone to perform high-level disinfection of the material. Based on this preliminary study, it can be concluded that the hydrodynamic system developed was effective in disinfecting surgical instruments, demonstrating the synergy of the two techniques. In addition, it is a system that does not produce harmful chemical waste to the environment and can be utilized for thermo-sensitive materials. [ABSTRACT FROM AUTHOR]