10 Recommendations For Point of Care Ultrasound Probe Disinfection

Ultrasound has become a cornerstone in the diagnosis and treatment of patients in many hospital disciplines of medicine and surgery and is increasingly being used in Critical Care, Emergency Departments (A&E), Anaesthesia, and indeed Primary Care and Specialty Outpatient Clinics. To achieve the full ultrasound benefits in patient care, medical teams need to consider the contamination risk over repeated use of probes as a vector for pathogen transmission.

New specialty guidelines

Various global guidelines have been published. But in response to current infectious diseases, specialty medical groups are publishing their own recommended guidelines, taking into account how ultrasound is practiced within their Specialty (Intensive Care, Emergency/A&E, Anaesthesia, Fertility Specialist), which is relevant to the wider medical community.

Based on these new emerging specialty guidelines, there are 10 recommendations to consider for ultrasound probe disinfection to prevent pathogen transmission during ultrasound use:

  1. Know When to Disinfect
  2. Ultrasound-Guided Procedures
  3. Obstetrics Gynaecologists Procedures
  4. Ultrasound Machine and Probe
  5. Use of sterile Probe Covers
  6. Use of Ultrasound Gel
  7. Documentation and Traceability
  8. Infection Control Risk Assessment
  9. Educational Training and Certification
  10. Current Methods of Disinfection

These recommendations address the emerging issues of care for patients with confirmed or suspected Corona Virus Disease 2019 (COVID-19) or potential risk to other infectious diseases Methicillin-resistant Staphylococcus aureus (MRSA) and High Risk Human papillomavirus (HPV). HPV is known as the silent killer that causes 99% all cervical cancers and associated with 5% of all cancers worldwide.7-9 


1. Know When to Disinfect

To know what disinfection level to apply to the ultrasound probe before a patient procedure, refer to the Spaulding classification.

Under the Spaulding classification the ultrasound probe is classified into non-critical probe, semi-critical probe and critical probe, determined by how the probe comes in contact with the patient’s procedure site and the level of cross-infection risk.1-6

Non-critical probe is low- level disinfected as the probe contacts intact skin or non-infected skin and the potential cross-infection risk is low.

Semi-critical probe is high level disinfected as the probe may contact non-intact skin (wound or burn) or mucus membrane and the potential risk of cross-infection is considered medium to high.

Critical probe should be sterilised, if not possible can be high level disinfected and placed inside a sterile cover to prevent the contamination of a sterile field. The potential risk of cross-infection is considered high.

 

Disinfection Levels

Low level Disinfectant: Kills most vegetative bacteria and some fungi and viruses but does not kill mycobacteria or bacterial spores.

High Level Disinfection: All viable microorganisms must be destroyed, except a small number bacterial spores

Sterilisation: All viable microorganisms must be destroyed

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HLD Chart

2. Ultrasound-guided procedures

Most ultrasound-guided procedures in A&E Departments and Intensive Care are urgent and are performed with live guidance involving sharp objects, such as needles, trocars and scalpels.

The setting presents an elevated risk of unintended micro or macro perforation of the sterile plastic probe cover, resulting in exposure of the patient and the equipment.

In response to the absence of clear evidence of harm as well as concerns to the practicality of HLD after ultrasound-guided procedures, the global guidelines1-6 permit LLD if the clinician judges that the transducer has not contacted “blood or body fluids noted during procedure” from potential contamination. The term “Noted” offers excessive ambiguity. That is why HLD is the only option in ultrasound-guided procedures

Chronos Central Lines & IV

Considering all risks, specifically to POCUS in A&E and Intensive Care practice, as well as the minimal time and cost difference between options, HLD is preferred and recommended over LLD as the standard of care following ultrasound-guided procedures.10-13

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Ultrasound-Guided Procedures
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Regional Anaesthesia Block

3. Obstetrics Gynaecologists Procedures

Some institutions and medical teams proceed to Low Level Disinfection (LLD) and may not be fully aware of the cross-infection risks after use of an ultrasound probe that is classified as semi-critical. However, LLD has been proven to be insufficient, as demonstrated by the results of a retrospective cohort study using linked national datasets from Scotland.4-5 Standards and guidelines recommend HLD as a minimum for semi-critical probes.

The risk of exposure to toxic residuals can impact oocyte retrieval, embryo transfer and other IVF applications during pelvis ultrasound probe procedures. Included phenol, hydrogen peroxide (30% w/v), formaldehyde (37% w/v), Sodium hypochlorite (4% w/v), glutaraldehyde (50% w/v), cupric ascorbate, and peracetic acid (32% w/v) toxicity.11-12

Select high level disinfection system proven to kill high-risk, cancer-causing HPV. Research reveals that virtually all cervical cancers (more than 99%) are caused by high-risk Human Papillomaviruses (HPV16 and HPV18 ).13

HPV is a highly resistant virus; more so than other non-enveloped viruses previously tested. Published test results showed that commonly used clinical disinfectants, including those used as sterilants in medical and dental healthcare facilities, have no effect on HPV16 and HPV18.14

Results suggest that healthcare facilities using endocavity ultrasound probes need to strongly consider disinfection methods that are effective against native HPV - adopting new technologies such as UV-C HLD.15

Dr. Craig Meyers, Ph.D. - gives his expertise in HPV research. He was the first lab to develop a technique to grow natural High-Risk HPV. He discusses how his research has been applied in changing clinical practice globally in ultrasound probe reprocessing. Webinar

Webinar - HPV Facts

Dr. Craig Meyers, Ph.D. - gives his expertise in HPV research. HPV best research evidence supports clinical change in Ultrasound probe reprocessing

Q&A  - Latest tests discussion

Dr. David J. Weber - What to Consider in Evidence-Based Practice in Ultrasound

 

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IVF success rate in mind!

4. Ultrasound Machine and Probe

Immediately cleaning following use, prevents drying and adherence of biological debris which may interfere with disinfection later.

Disinfection immediately before use minimises the risk of probe contamination. Individual policies must consider these factors in designing workflows reflecting local specifics.

Cleaning and Disinfection must apply to the entire ultrasound scanning equipment to adequately control the transmission of pathogens

High-frequency touch areas such as the keyboard, screen and probe holder are at risk of exposure to pathogens and require disinfection.1,7

 



Ultrasound Probes

Place ultrasound probe inside a clean cover may avoid contamination of probes following disinfection.


5. Use of Sterile Probe Covers

Sheath covers are mandatory for semi-critical procedures such as transrectal and trans-vaginal probes and critical procedures require a sterile sheath covers for procedures such as ultrasound-guided vascular access and intra-operative ultrasound.


Probe covers not 100% protection proof

Research studies show that up to 13% of condoms and 5% of commercial covers have tears pre and post-transvaginal ultrasound examinations.16-19 However, this integrity is subjectively estimated rather than factually proven. Most clinicians performing these procedures on a routine basis with high patient turnover can attest to the fact that perforation of the cover does occur, exposing the patient procedure site to cross-infection risk.20

 

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Cross Infection Risks in ultrasound examinations

 

In similar studies in Transoesophageal Echocardiography (TOE) studies question whether the cover sheath offers any advantage in reducing infection risk.21-26 As cleaning and disinfection are still needed to prevent probe contamination, it is not clear whether the cover sheath offers any advantage over standard measures for infection prevention.

 

Sheaths are subject to perforation which may be undetectable to the naked eye. Perforation rates are as high as 4.4%.21,23

Studies concluded, probes should undergo high level disinfection before each procedure and question whether sheath covers provide any advantage in reducing cross-infection risk.24-26

 


6. Use of Ultrasound Gel

Transmission of infection with ultrasound gel has been well reflected in the medical literature.27-30 Reusable containers present high-risk to patients due to potential for contamination of gel and bottle surface. While their use may be acceptable in low-risk situations, are high infection risk in A&E Departments and Critical Care.

Research studies clearly demonstrates that contaminated gel can lead to infections, but also highlight that a probe can be a vector for pathogen transmission.

Single-use sachets of sterile ultrasound gel are relatively cheap and present the best option to minimise potential contamination and cross-infection between patients. Routine warming of the gel is not recommended due to the increased risk of bacterial proliferation.

 

Picture1-1

 

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Emergency Department

7. Documentation and traceability

Documentation of HLD must include the date and time, scanner and transducers identifiers, the name of the person performing disinfection and chemical agents with batch numbers. This documentation must be stored for a period prescribed by the local policy.

To reduce cross-infection risk, it is preferable to have electronic documentation, moving to a paperless system

 

 


8. Infection Control Risk Assessment

The Infection control risk assessment aim is to keep the patient and medical staff safe and is a living document that forms the foundation of any comprehensive Infection Prevention and

Control (IPC) program.48-49
The ultrasound probe risk assessment is designed to determine the risk for each hazard by how bad (Severity of Harm) and how likely the potential harm (likelihood of Harm) can occur during the reprocessing (cleaning, disinfection, and traceability) of ultrasound probes.

 

 

 

Risk Matrix, example below, could be used to determine risk for each hazard: (how bad and how likely) and consequently identify risk prominence and areas for improvement

Risk Assessment Martix

 

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Infection Control Risk Assessment

9. Educational Training Videos – Certify Training

Most A&E and Intensive Care ultrasound studies are performed as a point of care investigations (POCUS), ranging from basic to highly advanced.31-46

Emergency Physicians and Intensive care doctors are traditionally responsible for cleaning and disinfection of ultrasound equipment. A survey of ICU and ED departments found that 50% of probes retained traces of blood despite current cleaning/disinfection regimes.46 This presents a clear danger to other patients, staff and visitors.

Adequate training in disinfection is needed due to significant variability of skills in infection control standards.

 

 

 

Healthcare companies that sell disinfection products need to provide educational tools to support training of medical staff in how to reduce cross-infection risk. They need to be available as either online training or in the form of training videos with certification option that training has been completed.

Germitec Online Training Website

 


10. Current methods of disinfection

Ultrasound probes cannot be sterilised and there are a number of different disinfection methods shown in the table below.

Different manufacturers produce an array of different products, each with advantages and disadvantages that are best assessed according to local needs.

Options exist for all disinfection methodology with and without need for the purchase of upfront capital equipment.
Suppliers of Disinfection

 

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Chronos UV-C HLD

Clinical Workflows

For clinical workflows that require a 10-minute patient examination time, with a 5-minute turnaround time (such as Women’s Health, Fertility Medicine, IVF, Emergency, Intensive care), Chronos is extremely efficient in quickly disinfecting ultrasound probes between patients to help maximise patient throughput.

Other HLD systems can take significantly longer, directly impacting the number of examinations that can be achieved per day.

 

Chronos workflows

Manual chemical processes, for example, increase patient turnaround time up to 30 minutes while automated Hydrogen Peroxide systems can add up to 14 minutes. To maintain a 5-minute turnaround time, purchasing extra probes and hiring dedicated staff in cleaning and disinfecting probes might be required. This adds additional costs on top of the consumable cost of chemicals and chemical indicator or test strips.50

For further information

On how Germitec can assist you in ultrasound probe high level disinfection contact us

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Chronos HLD Solution


References

x.1ACIPC-ASUM. Guidelines for Reprocessing Ultrasound Transducers. Australasian Journal of Ultrasound in Medicine. 2017;20(1):30-40. 2. CDC 2008. Guideline for Disinfection and Sterilization in Healthcare Facilities. 3. FDA 2008. Information for Manufacturers Seeking Marketing Clearance of Diagnostic Ultrasound Systems and Transducers. 4. Health Protection Scotland (HPS), NHS National Services Scotland (2017). NHS Scotland Risk Based Recommendations for the Decontamination of SemiInvasive Ultrasound Probes: Risk of infection following semi-invasive ultrasound procedures in Scotland, 2010 to 2016. Version 1.0. 5.Health Facilities Scotland, NHS National Services Scotland, Health Protection Scotland. Scotland, March 2016. NHS Scotland Guidance for Decontamination of Semi-Critical Ultrasound Probes; Semi-invasive and Non-invasive Ultrasound Probes. Document: HPS/HFS Version 1.0. 6. Health Service Executive (HSE) Quality Improvement Division (2017). HSE Guidance for Decontamination of Semi-critical Ultrasound Probes; Semi-invasive and Non-invasive Ultrasound Probes. Document: QPSD-GL-028-1. 7 Cartan Costello. et al (2020). Prevention of pathogen transmission during ultrasound use in the Intensive Care Unit: Recommendations from the College of Intensive Care Medicine Ultrasound Special Interest Group (USIG) https://doi.org/10.1002/ajum.12205 8.Ultrasound Transducer and Equipment Cleaning and Disinfection Authors: FUSIC Committee on behalf of the Intensive Care Society and endorsed by the FAMUS working group on behalf of the Society for Acute Medicine https://www.acutemedicine.org.uk/wp-content/uploads/2020/03/FUSIC_FAMUS-Decontamination-guidelines.pdf 9.Amer M. et al. ASE Statement on Point-of-Care Ultrasound (POCUS) During the 2019 Novel Coronavirus Pandemic. 2020 American Society of Echocardiography 10.ACEM (2020) COVID-19 Clinical Guidelines for Emergency Medicine Departments in Australia and New Zealand https://acem.org.au/COVID-19 11. Sagripanti JL, Bonifacino A. 2000. Cytotoxicity of liquid disinfectants. Surgical infections 1:3-14. 12. Ackerman, S.B., et al., Toxicity testing for human in vitro fertilization programs. J In Vitro Fert Embryo Transf, 1985. 2(3): p. 132-7. 13.Meyers J, Ryndock E, Conway MJ, Meyers C, Robison R. Susceptibility of high-risk human papillomavirus type 16 to clinical disinfectants. J Antimicrob Chemother. 2014;69(6):1546-50. 14.Meyers C, Milici J, Robison R (2017) UVC radiation as an effective disinfectant method to inactivate human papillomaviruses. PLoS ONE 12 (10): e0187377. 15.Maxime Pichon, Karine Lebail- Carval, Geneviève Billaud, Bruno Lina, Pascal Gaucherand and Yahia Mekki (2019) Decontamination of Intravaginal Probes Infected by Human Papillomavirus (HPV) Using UV-C Decontamination System. J. Clin. Med, 8, 1776; doi:10.3390/jcm8111776. 16. Basseal,j. et al. (2019).Analysis of the integrity of ultrasound probe covers used for transvaginal examinations.Australasian College for Infection Prevention and Control. Dec. 15. Vickery K, et al. Evaluation of an automated high-level disinfection technology for ultrasound transducers, Journal of Infection and Public Health, 2013. 17. Masood J et al. Condom perforation during transrectal ultrasound guided (TRUS) prostate biopsies: a potential infection risk. Int Urol Nephrol 2007;39(4):1121−4. 18. Leroy S. Infectious risk of endovaginal and transrectal ultrasonography: systematic review and meta-analysis. The Journal of hospital infection. 2013;83(2):99-106. NAN0046. 19. Bloc S1, Mercadal L, Garnier T, Komly B, Leclerc P, Morel B, Ecoffey C, Dhonneur G. (2011) Evaluation of a new disinfection method for ultrasound probes used for regional anesthesia: ultraviolet C light. J Ultrasound Med. 2011 Jun;30(6):785-8. https://www.ncbi.nlm.nih.gov/pubmed/21632992 20. Geneviève Côté, André Denault. Review Article: Transesophageal echocardiography-related complications [Complications associées à l’échocardiographie transoesophagienne] Can J Anesth 2008 / 55: 9 / pp 622–647. 21. Fritz S, Hust MH, Ochs C, Gratwohl I, Staiger M, Braun B. Use of a latex cover sheath for transesophageal echocardiography (TEE) instead of regular disinfection of the echoscope? Clin Cardiol 1993; 16: 737–40. 22. Khandheria BK. The transesophageal echocardiographic examination: is it safe? Echocardiography 1994; 11: 55–63. 23. Richard Steeds. et al. Guidelines for transoesophageal echocardiographic probe cleaning and disinfection from the British Society of Echocardiography Article in European Heart Journal – Cardiovascular Imaging October 2011. 24. Cote G, Denault A. Transoesophageal echocardiography-related complications. Can J Anesth 2008; 55(9): 622-647. 25. Fritz S, Hust MH, Ochs C, et al. Use of latex cover sheath for transoesophageal echocardiography (TEE) instead of regular disinfection of echoscope? ClinCardiol 1993;16:737-40. 26. Abdelfattah R, Aljumaah S, Alqahtani A, Althawadi S, Barron I, Almofada S. Outbreak of Burkholderia cepacia bacteraemia in a tertiary care centre due to contaminated ultrasound probe gel. Journal of Hospital Infection. 2017;pii:S0195-6701(17)30516-9. 27. Olshtain-Pops K, Block C, Temper V et al. An outbreak of Achromobacter xylosoxidans associated with ultrasound gel used during transrectal ultrasound guided prostate biopsy. J Urol 2011:185(1):144-147. 28. Oleszkowicz S, Chittick P, Russo V, Keller P, Sims M, Band J. Infections associated with use of ultrasound transmission gel: proposed guidelines to minimize risk. Infect Control Hosp Epidemiol 2012; 33: 1235. 29. Shaban R, Maloney S, Gerrard J, Collignon P et al. Outbreak of healthcare associated Burkholderia cenocepacia bacteremia and infection attributed to contaminated sterile gel used for central line insertion under ultrasound guidance and other procedures. American J Infection Control 2017;45(9):954-958. 30. Yastrebov K, Costello C, Grealy R, et al Echocardiography Time Audit Study .Anaesth Intensive Care. 2017 Sep;45(5):632-63. 31. Cholley B, Vieillard-Baron A, Mebazaa A (2005) Echocardiography in the ICU: time for widespread use! Intensive Care Med 32:9–10. 32. A. Levitov, H.L. Frankel, M. Blaivas, et al. Guidelines for the appropriate use of bedside general and cardiac ultrasonography in the evaluation of critically ill patients-part II: cardiac ultrasonography. Crit Care Med 2016; 44: 1206-27. 33. M Narasimhan, S Koenig, P Mayo. Advanced Echocardiography for the Critical Care Physician. 2014; 145:129-134. 34. Neskovic AN et al. Emergency echocardiography: the European Association of Cardiovascular imaging recomendartions. Eur Hear Journal-Cardiovascular imaging 2013; 14: 1-11. 35. Porter TR et al. Guidelines for the Use of Echocardiography as a Monitor for Therapeutic intervention in adults: a Report from the American society of Echocardiography. J Am soc Echocardiography 2015;28: 40-56. 36. Neskovic AN, et al. Focus Cardiac Ultrasound: the European Association of Cardiovascular imaging viewpoint. Eur Heart J Cardiovasc Imaging 2014; 15: 956-960. 37. Guidelines for the Appropriate Use of Bedside General and Cardiac Ultrasonography in the Evaluation of Critically Ill Patients—Part I: General Ultrasonography Crit Care Med 2015; 43:2479- 2501. 38. 2014 ESC Guidelines on the diagnosis and management of acute pulmonary embolism. European Heart Journal (2014) 35, 3033–3080. 39. Protocol for Adult Advanced Life support. Guideline 11.2 2012. Australian Resuscitation council. New Zealand Resuscitation Council. 40. NSW HEALTH -Policy Directive PD 2011_060 “ Central venous Access Insertion and Post Insertion Care” [internet] Available at www.health.nsw.gov.au/mhr/Publications. 41. NSW Agency for Clinical Innovation : Pleural Drain Insertion in Adults- Consensus Guidelines 2012 [internet] Available at www.aci.health.nsw.gov.au/ data/.../ACI-pleural-drain-web-v1-2.pdf. 42. Mercaldi CJ, Lanes SF. Ultrasound guidance decreases complications and improves the cost of care among patients undergoing thoracentesis and paracentesis. Chest 2013; 143:532. 43. Patel PA, Ernst FR, Gunnarsson CL. Ultrasonography guidance reduces complications and costs associated with thoracentesis procedures. J Clin Ultrasound 2012; 40:135. 44. Havelock T, Teoh R, Laws D, et al. Pleural procedures and thoracic ultrasound: British Thoracic Society Pleural Disease Guideline 2010. Thorax 2010; 65 Suppl 2:ii61. 45. ANZICS, Percutaneous Dilatational Tracheostomy Consensus Statement, 2014 [internet] Available at http://www.anzics.com.au. 46. Keys M, Sim B, Thom O, Tunbridge M, Barnett A, Fraser J. Efforts to Attenuate the Spread of Infection (EASI): a prospective, observational multi-center survey of ultrasound equipment in Australian emergency departments and intensive care units. Crit Care Resusc 2015; 17: 43–6. 47. Angela Ai, et al. (2020) Barriers and facilitators to standardization of ultrasound use and probe disinfection in the ambulatory setting. Infection Control & Hospital Epidemiology (2020), 1–3 doi:10.1017/ice.2020.13. 48. Marcia P (2016) 10 Elements to Consider When Conducting an Infection Risk Assessment, infection control today. 49. https://www.cdc.gov/hai/prevent/infection-control-assessment-tools.html. 501. Johnson et al.,Evaluation of a Hydrogen Peroxide-Based System for High-Level Disinfection of Vaginal Ultrasound Probes, Journal of Ultrasound Medicine, 32:1799-804, 2013.