<scp>ISUOG</scp> Safety Committee Position Statement on safe performance of obstetric and gynecological scans and equipment cleaning in context of COVID‐19

Abstract

In view of the challenges of the current coronavirus (COVID-19) pandemic and to protect both patients and ultrasound providers (physicians, sonographers, allied professionals), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) has compiled the following expert-opinion-based guidance for the performance of ultrasound investigations in pregnancy and for gynecological indications. The guidance assumes that robust local processes are in place for cleaning ultrasound equipment after each patient routinely, and gives specific recommendations for ultrasound examinations in suspected or confirmed cases of COVID-19. The novel coronavirus infection spreads very easily and even asymptomatic patients or caregivers can be a route of transmission. The two main principles of undertaking safe ultrasound examinations during the COVID-19 pandemic are (1) prevention of the spread of the virus and (2) protection of the healthcare workers. Ultrasound is an essential part of obstetric and gynecological care, but exposes the patient and the caregiver to high risks, given the impossibility of keeping the recommended distance between them during the ultrasound scan. It is therefore essential to take all possible precautions when undertaking routine clinical activity. Every country follows national and international guidelines for the performance of routine or targeted ultrasound investigations1-4. The decision as to what constitutes an elective or an emergency examination is to be decided locally and will not be addressed in this document. This document is intended to serve as an adjunct in the context of the current COVID-19 pandemic and should be considered in conjunction with relevant advice from other organizations (Appendix S1). The aspects that should be considered when planning an ultrasound examination in an obstetric or gynecological care setting in the context of the COVID-19 pandemic are: (1) how to prepare and clean the ultrasound room and equipment and (2) how to protect the patient and ultrasound providers (physicians, sonographers, allied professionals). The transducer and ultrasound equipment should be cleaned with a compatible LLD after each patient, in accordance with local guidelines. PREPARATION AND CLEANING OF ULTRASOUND EQUIPMENT Since information about SARS-CoV-2 is incomplete, additional use of high-level disinfectants is recommended; however, this advice is manufacturer-specific. High-level disinfectants include ethanol 80–95% (exposure time 30 s), 2-propanol 75–100% (exposure time 30 s), 2-propanol and 1-propanol 45% and 30% (exposure time 30 s), sodium hypochlorite 0.21% (Antisapril Blu 2%, exposure time 30 s), glutaraldehyde 2.5% (exposure time 5 min) and 0.5% (CIDEX OPA, exposure time 2 min), hydrogen peroxide 0.5% (REVITAL-OX RESERT, exposure time 1 min)6. Protective eyewear and gloves should be used when cleaning, disinfecting or sterilizing any equipment. PREPARATION AND CLEANING OF ULTRASOUND TRANSDUCER Guidelines regarding cleaning of ultrasound transducers between patients are available7-10. Coronaviruses are enveloped viruses, which are the least resistant to inactivation by disinfection. The structure of these viruses includes a lipid envelope, which is easily disrupted by most disinfectants suitable for use on ultrasound systems and transducers. According to the Spaulding classification system, medical devices are classified according to the infection risk they present as non-critical, semi-critical and critical (also referred to as low-risk, medium-risk and high-risk). Non-critical devices present the lowest risk for infection as they come in contact with intact skin, such as transabdominal transducers. Low- or intermediate-level disinfection is recommended, which will eradicate most bacteria (but not bacterial spores) and fungi, as well as certain types of viruses, including human immunodeficiency virus (HIV). Semi-critical devices are those that present a higher risk for infection because of contact with non-intact skin or mucous membranes. Transvaginal transducers belong to this category. High-level disinfection for destruction of all microorganisms, including SARS-CoV-2, is recommended and can be performed by means of solutions containing sodium hypochlorite or other disinfectants as detailed above. Critical devices, such as transducers used in invasive procedures, should undergo sterilization as per medical facility guidelines irrespective of whether a probe cover is used. Preparation of the ultrasound transducer consists of two steps: cleaning and disinfection. Any products used for cleaning or disinfection should be compatible with the ultrasound equipment, as determined by the ultrasound equipment manufacturer10. Certain products may damage ultrasound equipment or transducers and invalidate warranties. This is an important first step since any remaining gel can act as a barrier to the disinfectant thus diminishing its efficacy. The USA Centers for Disease Control and Prevention (CDC) defines cleaning as ‘the removal of foreign material (e.g. soil and organic material) from objects and is normally accomplished using water with detergents or enzymatic products’. Ineffective cleaning prior to disinfection can limit the effectiveness of chemical disinfection. Current guidelines for cleaning transvaginal transducers8, 10 recommend using running water to remove any residual gel or debris from the probe before cleansing thoroughly the transducer using a damp gauze pad, or other soft cloth, and a small amount of mild non-abrasive liquid soap (approved for use on medical instruments). The use of a small brush especially for the crevices and areas of angulation should be considered, depending on the design of the particular transducer. The transducer should then be rinsed thoroughly with running water and dried with a soft cloth or paper towel. Always refer to your facility's infection control policies and protocols, as well as the transducer manufacturer's instruction for use and labels for use. Disinfection practices are evolving constantly, and this is the most current to date. As mentioned above, high-level disinfection is recommended for transvaginal but not transabdominal transducers. Specific product instructions should be consulted. Available methods (current at the time of publication) include: Note that common household bleach (5.25% sodium hypochlorite) diluted to yield 500 parts per million chlorine (10 mL in one L of tap water), although effective is not recommended by manufacturers because it can potentially cause damage to metal and plastic parts of the transducer. Mention of this disinfectant here does not imply that we consider it to be appropriate, but we are aware that it is used in some settings. After cleaning, store transducer in a clean closet or its case with foam inset to prevent damage and protect from contamination with dirt, if it is not going to be used immediately. This document was prepared by and under the auspices of the Safety Committee of ISUOG and members co-opted for the purposes of compiling the document. The authors are: L. C. Poon, Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR J. S. Abramowicz, Department of Obstetrics and Gynecology, University of Chicago, Chicago, IL, USA A. Dall'Asta, Department of Medicine and Surgery, Obstetrics and Gynecology Unit, University of Parma, Parma, Italy R. Sande, Department of Obstetrics and Gynecology, Stavanger University Hospital, Stavanger, Norway G. ter Haar, Therapy Ultrasound, Division of Radiotherapy & Imaging, Joint Department of Physics, Royal Marsden Hospital, Institute of Cancer Research, Surrey, UK K. Maršal, Department of Obstetrics and Gynecology (Emeritus), Lund University, University Hospital, Lund, Sweden C. Brezinka, Department of Obstetrics and Gynecology, Medical University of Innsbruck, Innsbruck, Austria P. Miloro, Ultrasound and Underwater Acoustics, National Physical Laboratory, Teddington, UK J. M. Basseal, Discipline of Infectious Diseases & Immunology, Faculty of Medicine and Health, The University of Sydney; and Australasian Society for Ultrasound in Medicine (ASUM), NSW, Australia S. C. Westerway, School of Dentistry & Health Sciences, Charles Sturt University; and Australasian Society for Ultrasound in Medicine (ASUM), Sydney, NSW, Australia R. S. Abu-Rustum, Department of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville, FL, USA C. Lees (Chair), Imperial College School of Medicine, Imperial College London, London, UK We thank Suzanne Beattie Jones, Maternity Ultrasound Services Manager, Imperial College Healthcare NHS Trust, London, UK, for her contribution. Where commercially available products are referenced, this does not imply ISUOG endorsement. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.