The ultrasound unit and infection control - Are we on the right track?

Practice 'safe scans': why ultrasound transducer covers should be considered best practice

Single-injection, ultrasound-guided nerve block procedures involve puncturing the skin in close proximity to an ultrasound transducer, creating a potential vector for transmission of microbial organisms when skin flora and blood come into contact with the probe. Practice patterns regarding disinfection of the transducer and the use of barrier protection are inconsistent, ranging from sterile sleeve probe covers to no cover at all. Although sleeve probe covers are easy and straightforward to use and serve to protect patients, providers and medical equipment, their utilisation remains controversial. Standardisation of their use eliminates the impact of improper or haphazard probe disinfection and makes infection control practices consistent and reproducible. This position is shared by multiple societies and authorities on ultrasound and acute care medicine. In this Daring Discourse, we outline the arguments supporting the utilisation of single-use sleeve probe covers to ensure patient safety with respect to vector-borne transmission of microbes during single-injection regional anaesthesia procedures.

Infection prevention and control in medical imaging surveys: The need to map to guidelines to address systemic issues?

BACKGROUND

Infection prevention and control (IPC) in the medical imaging (MI) setting is recognised as an important factor in providing high-quality patient care and safe working conditions. Surveys are commonly used and have advantages for IPC research. The aim of this study was to identify the core concepts in surveys published in the literature that examined IPC in MI environments.

METHODS

A literature review was conducted to identify studies that employed a survey relating to IPC in the MI setting. For each included study, descriptive study information and survey information were extracted. For IPC-specific survey items, directed content analysis was undertaken, using eleven pre-determined codes based on the 'Australian Guidelines for the Prevention and Control of Infection in Healthcare'. Content that related to 'Knowledge', 'Attitudes' and 'Practice' were also identified.

RESULTS

A total of 23 studies and 21 unique surveys were included in this review. IPC-specific survey items assessed diverse dimensions of IPC, most commonly relating to 'transmission-based precautions' and 'applying standard and transmission-based precautions during procedures'. 'Practice' and 'Knowledge' related survey items were most frequent, compared to 'Attitudes'.

CONCLUSION

MI research using survey methods have focused on the 'entry' points of IPC, rather than systemic IPC matters around policy, education, and stewardship. The concepts of 'Knowledge', 'Attitudes' and 'Practice' are integrated in IPC surveys in the MI context, with a greater focus evident on staff knowledge and practice. Existing topics within IPC surveys in MI are tailored to individual studies and locales, with lack of consistency to national frameworks.

Improving hospital-based point-of-care ultrasound cleaning practices using targeted interventions: a pre-post study

BACKGROUND

Point-of-care ultrasound (POCUS) devices are becoming more widely used in healthcare and have the potential to act as fomites. The objective of this project was to study the thoroughness of cleaning of POCUS machines before and after a quality improvement initiative. We designed a mixed-methods, pre/post study which took place over the course of one year at a university-affiliated health center. Cleaning rates of four ultrasound machines used by hospital medicine and critical care medicine services were evaluated using fluorescent marking. Interventions targeted physicians' knowledge of best practices and improved access to cleaning supplies. Pre- and post-intervention cleaning rates were compared using a generalized linear model. The impact of the corona virus disease of 2019 (COVID-19) pandemic on baseline cleaning rates was also evaluated. Physicians' attitudes and knowledge of cleaning practices were evaluated via unpaired pre/post surveys.

RESULTS

There was significant improvement in thoroughness of cleaning following intervention (pre 0.62, SE 0.05; post 0.89, SE 0.07), p < 0.0001). There was no difference in baseline cleaning rates before (0.63, SE 0.09) and after (0.61, SE 0.1) the onset of the COVID-19 pandemic (p = 0.78). Post-intervention surveying found improved understanding of guideline-based cleaning practice, better performance on knowledge-based questions, and fewer reported barriers to machine cleaning.

CONCLUSION

Thoroughness of cleaning of POCUS machines can be improved with practical interventions that target knowledge and access to cleaning supplies.

Does the COVID-19 pandemic cause late diagnosis and delay in treatment in developmental dysplasia of hip patients?

BACKGROUND

The aim of the current study was to search the effect of COVID-19 restriction on developmental dysplasia of hip (DDH) screening.

MATERIAL AND METHODS

We retrospectively reviewed the patients who brought to DDH screening in April-May and June-July 2020 and compared with the same period of 2019. We recorded age, gender, DDH type and risk factors of the patients.

RESULTS

The number of patients taken for DDH screening was 430 and 400 in April-May 2019 and June-July 2019, respectively. In 2020, the number of patients taken for DDH screening was 159 and 776 in the same period, respectively. Thirteen patients were diagnosed with DDH older than 3 months age in June-July 2020. There were only two patients in same period in 2019. In 2020, 6 of 13 patients who applied to the hospital late for the routine US and had pathologic hips were not taken to orthopaedics or follow-up by their families.

CONCLUSION

In the era of COVID-19, the number of late diagnosis and lost follow-up for DDH are increased. To prevent future morbidities and reduce surgical interventions, special measures should be taken.

Ultrasound-guided regional anesthesia in COVID-19 and future pandemics: infection control

PURPOSE OF REVIEW

Infection control is inherent in ultrasound-guided regional anesthesia practice, because ultrasound transducer and coupling gel can be vectors for pathogen transmission. We reviewed the current standards and recommendations of ultrasound transducer cleaning, disinfection, and safe handling of ultrasound equipment. Based on the available data, we propose a set of practical recommendations applicable to coronavirus disease 2019 (COVID-19) pandemic and future epidemics.

RECENT FINDINGS

Regional anesthesia is often preferred over general anesthesia for COVID-19 patients. Avoidance of general anesthesia reduces the need for aerosol generating procedures. Administration of ultrasound-guided regional anesthesia and surgery under regional anesthesia in COVID-19 patients requires careful infectious precautions to prevent the viral spread through the use equipment.

SUMMARY

Ultrasound machine, transducer and coupling gel can serve as a vector for transmission of pathogens. In the era of COVID-19 pandemic, standardized strategies are recommended to minimize the risk of spread of COVID-19 to both patients and the healthcare providers.

[Disinfection of transvaginal ultrasound probes-A current overview of methods and recommendations]

Disinfection of ultrasound probes, especially of transvaginal probes, has been under discussion during recent years and there have been several new regulations and recommendations as well as trends in the field of disinfection methods. This article provides a review and summary of the current state of knowledge.

Minimizing cross transmission of SARS-CoV-2 in obstetric ultrasound during COVID-19 pandemic

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated infection (COVID-19) is affecting populations worldwide. This statement may serve as guidance for infection prevention and safe ultrasound practices during the COVID-19 pandemic. Ultrasound examination is a fundamental part of obstetric care, yet it is a potential vector for transmission of SARS-CoV-2. Decontamination methods should always be implemented for ultrasound equipment, especially in the presence of suspected or confirmed COVID-19 cases. There must be workflow policies to protect pregnant women and healthcare providers from nosocomial cross transmission of SARS-CoV-2. Cleaning and disinfecting of equipment must be in accordance with their potential of pathogen transmission. Consider using telemedicine and genetic technologies as an adjunctive of obstetric ultrasound to reduce patient crowding. Patient triage and education of healthcare providers of infection prevention are crucial to minimize cross contamination of SARS-CoV-2 during obstetric ultrasound.

Identification and Analysis of Bacterial Contamination of Ultrasound Transducers and Multiuse Ultrasound Transmission Gel Bottle Tips Before and After the Aseptic Cleansing Technique

OBJECTIVES

To provide a descriptive analysis for species identification of culture and Gram stain results from ultrasound transducers and multiuse ultrasound transmission gel bottle tips in active clinical use and to compare bacterial cultures from ultrasound transducers before and after aseptic cleansing.

METHODS

A prospective blinded descriptive analytic study of 18 distinct clinical care sites within a single primary clinical institution was conducted. Before and after a disinfectant towel cleanse, transducers were pressed against tryptic soy agar contact plates. Plates were deidentified and submitted for blind incubation, Gram staining, and species identification with microsequencing. Results were classified as clinically relevant (CR) or non-clinically relevant. In total, 188 samples were analyzed: 80 from ultrasound transducers before and cleansing, 13 from multiuse gel bottle tips before and after cleansing, and 2 precleansing samples from the data collector's pen and badge.

RESULTS

Fifty-nine precleansing samples (73.8%) grew cultures with CR bacteria, and 21 samples (26.3%) did not. Staphylococcus simulans represented 31.0% of all positive culture samples. Thirteen postcleansing samples (16.3%) grew cultures with CR bacteria, equating to a 78.0% reduction of CR bacterial growth (likelihood ratio, 57.10; P < .001).

CONCLUSIONS

Ultrasound transducers have a notable CR bacterial burden and may serve as potential infective vectors. Aseptic cleansing effectively eliminates most of the bacterial load from ultrasound transducers, but some bacteria persist, presenting a risk of nosocomial infection with ultrasound-guided interventions. These findings support American Institute of Ultrasound in Medicine 2018 guidelines intended to ensure an appropriate level of transducer preparation based on the examination type while emphasizing rational infection control measures to minimize the risk of potential patient harm.

Glow Powder: See the Germs? An Innovative Teaching Technique in a Student Sonography Laboratory

The purpose of this study was to compare the disinfection rate of a laboratory environment before and after glow powder exposure and training of sonography students (n = 23) and establish if glow powder was an effective teaching technique for infection protection and control (IPC). Fourteen locations at four scanning stations were contaminated with glow powder, visible under ultraviolet light. Students were shown contaminated areas and debriefed on the importance of disinfection. This activity was repeated to ascertain effectiveness of the training. In total, 204 areas were examined for contamination. Observation 1 revealed 21 locations (30.8%), and observation 2 detected glow powder on 12 locations (17.6%). Overall decrease in contamination rate was 13%. The gel bottle was the most frequently contaminated. The curved 3.5-MHz transducer was consistently cleaned. Disinfectant spray, time gain compensation, bed, stool, screen, and handles of the machine remained contaminated. Students’ IPC increased significantly after glow powder training, and secondary spread was reduced by 16%.

Reviewing the Use of Glutaraldehyde for High-level Disinfection by Sonographers

A review of recent literature has demonstrated that ultrasound transducers may harbor bacteria and viruses that could cause cross-contamination for patients. Reducing the risk of cross-contamination is achieved by high-level disinfection of ultrasound transducers. One of the main types of high-level disinfectants (HLD) used in performing sonography is glutaraldehyde (GA). While GA-based HLDs are cleared in abundance by the FDA and compatible with most transducers, GA has been reported to cause extensive adverse effects and has limited efficacy as a disinfectant. This literature review provides a current set of studies that discuss high-level disinfection of ultrasound transducers, GA use, exposure, and alternatives. This information could be used by practitioners to carefully consider how to effectively clean ultrasound transducers and supporting equipment. Additional guidance is provided on how to potentially minimize GA exposure and suggestions for protecting patients during their imaging examination.

Infection prevention and control in ultrasound - best practice recommendations from the European Society of Radiology Ultrasound Working Group

OBJECTIVES

The objective of these recommendations is to highlight the importance of infection prevention and control in ultrasound (US), including diagnostic and interventional settings.

METHODS

Review of available publications and discussion within a multidisciplinary group consistent of radiologists and microbiologists, in consultation with European patient and industry representatives.

RECOMMENDATIONS

Good basic hygiene standards are essential. All US equipment must be approved prior to first use, including hand held devices. Any equipment in direct patient contact must be cleaned and disinfected prior to first use and after every examination. Regular deep cleaning of the entire US machine and environment should be undertaken. Faulty transducers should not be used. As outlined in presented flowcharts, low level disinfection is sufficient for standard US on intact skin. For all other minor and major interventional procedures as well as all endo-cavity US, high level disinfection is mandatory. Dedicated transducer covers must be used when transducers are in contact with mucous membranes or body fluids and sterile gel should be used inside and outside covers.

CONCLUSIONS

Good standards of basic hygiene and thorough decontamination of all US equipment as well as appropriate use of US gel and transducer covers are essential to keep patients safe.

MAIN MESSAGES

• Transducers must be cleaned/disinfected before first use and after every examination. • Low level disinfection is sufficient for standard US on intact skin. • High level disinfection is mandatory for endo-cavity US and all interventions. • Dedicated transducer covers must be used for endo-cavity US and all interventions. • Sterile gel should be used for all endo-cavity US and all interventions.