With the continuous development of medical imaging technology, ultrasonic medical equipment has been paid more and more attention by hospitals, and its use frequency is also higher and higher. Now ultrasonic examination covers almost all departments in the hospital. With the wide use of ultrasonic examination, more and more clinical departments have been inseparable from ultrasonic examination. The probe is a bridge for clinical service. Medical ultrasonic probes are often used repeatedly, but they are also very vulnerable to damage. Today, Xiaobian has sorted out some documents related to ultrasonic probe disinfection for your reference.

Pollution of ultrasonic probe

Repeated use of ultrasonic probes is prone to bacterial contamination. There is a statistically significant difference in the positive rate of probes used in different specialties. The positive rate of functional departments is significantly higher than that of Obstetrics and Gynecology and physical examination departments, and the positive rate of Obstetrics and gynecology is higher than that of physical examination departments. The common bacteria are Staphylococcus, Escherichia coli, heterotypic Citrobacter, Bacillus subtilis, Shigella, etc. At the same time, the literature also confirmed that the ultrasonic probe may have become the residence of drug-resistant bacteria.

Pollution source of ultrasonic probe

Because the ultrasonic examination instrument needs to emit the ultrasonic sound source into the tissue and use the echo for diagnosis or treatment, the probe of the ultrasonic instrument needs to contact the skin or mucous membrane of the examinee. In order to make the examination image clear, the ultrasonic couplant of the acoustic transmission medium should be coated before the examination, which creates conditions for the transmission of bacteria between the examinee. If it is not handled well, there is a potential threat of microbial transmission. Summary: bacteria on the skin of the subject, bacteria on the mucosa, bacteria in the couplant, bacteria on the paper towel erasing the couplant.

Recommended method of detergent disinfection

At present, there is no national or industrial standard specifically for the surface disinfection requirements and effect evaluation of medical ultrasonic probes in China, which leads to a variety of cleaning and disinfection methods of ultrasonic probes in domestic hospitals. Most of them are selected only d on the experience of doctors, which is lack of scientificity and effectiveness. In order to prevent and control nosocomial infection caused by microbial contamination on the surface of ultrasonic diagnostic equipment, some foreign countries and regions have formulated corresponding operating specifications and standards. d on the general consensus of the European Society of Radiology ultrasound working group, the American Institute of ultrasound medicine, the Canadian Society for social medicine ultrasound diagnosis, the Australian Society of medical ultrasound and the College of prevention and control, the main recommendations for probe cleaning and disinfection procedures are as follows:

Cleaning and drying of ultrasonic probe

The residual couplant and dander on the probe will prevent the penetration and action of the disinfectant, so the probe must be thoroughly and effectively cleaned and dried before disinfection to ensure the subsequent disinfection effect. Foreign guidelines recommend the use of soap and running water or detergent wipes to remove residual couplants and debris. When washing, the water temperature should not exceed 60 ° C. the probe should face down and move gently. Do not bend or stretch the cable excessively. If there are grooves or gaps on the probe, it must be thoroughly cleaned with a soft brush. Relevant foreign guidelines do not recommend using dry paper towels to wipe directly for cleaning, which is not as effective as detergent or soap, and may scratch the surface of the probe. After cleaning the probe, wipe it with a dry soft cloth or dry it naturally to avoid diluting the disinfectant applied later and reducing the disinfection effect.

Disinfection of ultrasonic probe

1. Selection of disinfection methods

The risk of cross infection associated with ultrasound operation mainly depends on whether it is in contact with body fluids and the degree of invasion of the operation. Usually, ultrasonic probes that contact intact skin only need low-level disinfection to eliminate most bacteria, some fungi and viruses. When performing intraluminal ultrasound, interventional operation, and ultrasonic examination in contact with infected or damaged skin and wounds, the ultrasonic equipment is in contact with the patient's mucosa or body fluid. Therefore, it is necessary to strictly disinfect the equipment directly in contact with the patient, including the ultrasonic probe, to kill all active pathogens except spores. The probe sensor is sensitive to heat and is not suitable for high-temperature disinfection or sterilization. 75% ethanol, chlorine containing disinfectant and peracetic acid can effectively kill the virus, but these chemical disinfectants cause great damage to the probe sensor and are easy to cause probe aging. Chemical disinfectants such as glutaraldehyde and formaldehyde can damage the health of patients and medical staff through direct contact or inhalation, so routine use is not recommended. Foreign literature shows that compared with hydrogen peroxide, UV has a relatively poor killing effect on microorganisms. In addition, ultraviolet radiation is difficult to achieve real-time clinical disinfection, which is not suitable for daily disinfection of probes.

2. Low level disinfection method

The low-level disinfection method is applicable to the probe that contacts the complete skin. Disinfection wipes, disinfection foam or other approved disinfection agents that meet the quality requirements can be selected. Quaternary ammonium salt disinfectants can effectively kill most pathogens, including coronavirus. They are less irritating and corrosive, and have no bad smell. They are commonly used for cleaning and disinfection of the surface of medical equipment. The composite double chain quaternary ammonium salt disinfectant wipes take the non-woven fabric with good water absorption as the material, and soak the composite double chain quaternary ammonium salt disinfectant (the total quaternary ammonium salt content is 0.18% - 0.22%). Domestic research shows that when it acts on the ultrasonic probe for 1 ~ 2 minutes, the sterilization rate can reach 100%, and the sterilization effect can last for 6 hours. Quaternary ammonium salt disinfection wipes have good cleaning power and disinfection effect. They are safe and convenient to use. They are a good choice for low-level disinfection of ultrasonic probes in daily life and during the epidemic.

3. High level disinfection method

All intraluminal ultrasound, interventional procedures, and ultrasonic examinations in contact with infected or damaged skin require high-level disinfection of the probe and handle, including the cable connected to it. Common methods include high-level chemical disinfectant immersion disinfection, and automatic high-level disinfection system d on chemical disinfectant or ultraviolet light. Immersion disinfection is a commonly used disinfection method in China. This method immerses the probe in a special liquid for a certain time, and the disinfectants used include preparations d on glutaraldehyde or succinic aldehyde. Using this method, the probe must be disinfected in a separate bracket for at least 15min. After disinfection, the probe must be thoroughly washed with drinking water or water of higher quality to remove residual allergic or toxic substances. The ultrasound examination area is usually narrow and poorly ventilated, which may cause inhalation related health hazards. The Tryphon EPR system using hydrogen peroxide is a commonly used automatic disinfection system abroad, which can provide high-level disinfection of the entire ultrasonic probe (including the handle) within a period of 7min, and has good material compatibility. In the process of mechanical disinfection controlled by software, the whole ultrasonic probe is placed in a sealed disinfection room, and the system releases hydrogen peroxide ultrafine aerosol to wet all surfaces of the probe for disinfection, and then the system automatically decomposes hydrogen peroxide into oxygen and water. The desktop device can be placed directly next to the ultrasonic device without removing the probe from the host, which is convenient for daily application.

Source

1: Basic medicine and clinic, September 2020, Volume 40, Issue 9, article number: 1001-6325 (2020) 09-1261-05 disinfection of ultrasound equipment in non isolated diagnosis areas during covid-19 epidemic, Meng Wei, Wang ruojiao, Lu Ke, Zhang Yixiu, Li Jianchu, Li Wenbo, Wang Ming, Department of ultrasound medicine, Beijing Xiehe Hospital, Chinese Academy of Medical Sciences

2: Chinese Journal of disinfection, Volume 29, Issue 9, 2012, technical requirements for disinfection of medical ultrasonic probes, Shen Peng, Tianjin disease