Endocavity Ultrasound Transducers: Why High-Level Disinfection Is Necessary

Abstract

As a medical imaging modality, ultrasound is used by a wide cross-section of practitioners including radiologists, obstetricians, gynecologists, gastroenterologists, urologists and cardiologists. The increasing popularity of ultrasound as a diagnostic tool is due not only to the ease of use and portability of systems, but also to the perceived safety aspect of the examination. This latter point needs to be examined. As with any reusable medical device, the ultrasound transducer, also known as a probe, could potentially be a vector for the transmission of pathogenic viruses and fungi between patients if not correctly disinfected after each use. This transmission risk is magnified for an endocavity transducer that has come in contact with the vagina, anal canal or oral cavity, as it could be contaminated with organisms transmitted by blood or mucosal, genital or rectal secretions. Based on the Spaulding system, transducers that come in contact with mucous membranes are classified as semi-critical devices that require high-level disinfection (HLD) after each patient procedure. This HLD process should eliminate all microorganisms except high numbers of bacterial endospores. Only a small number of countries worldwide have implemented transducer reprocessing guidelines that adhere to the Spaulding classification and recommend HLD for endocavity transducers. Overall, there is a lack of conformity among global health agencies regarding the use of HLD for endocavity transducers. This is primarily due to the perception that the infection transmission risk is negligible and that if an endocavity transducer has been covered with a single-use sheath for the procedure, then low-level disinfection provides sufficient protection against pathogen transmission. The objective of this study was to review the published risk of infection transmission from endocavity transducers. By highlighting the outbreaks and case reports that implicate pathogen transmission from transducers, we posit that HLD should be a global standard of practice for the reprocessing of endocavity transducers. It requires substantial time for national health administrations to develop and legislate new recommendations, and for practice changes to be accepted and implemented by healthcare providers. We recommend that Joint Commission International (JCI) and other equivalent organizations enforce the use of HLD of endocavity ultrasound transducers during their accreditation reviews.

Zusammenfassung

Als bildgebendes Verfahren in der Medizin wird Ultraschall von Ärzten verschiedenster Fachrichtungen eingesetzt, darunter Radiologen, Geburtshelfer, Gynäkologen, Gastroenterologen, Urologen und Kardiologen. Die zunehmende Beliebtheit von Ultraschall als diagnostisches Hilfsmittel ist nicht nur auf die einfache Handhabung und Tragbarkeit der Systeme zurückzuführen, sondern auch auf die vermeintlichen Sicherheitsaspekte der Untersuchung. Dieser letztgenannte Punkt muss untersucht werden. Wie bei jedem wiederverwendbaren medizinischen Gerät könnte der Ultraschallkopf, der auch als Sonde bezeichnet wird, potenziell ein Vektor für die Übertragung pathogener Viren und Pilze zwischen den Patienten sein, wenn er nicht nach jedem Gebrauch korrekt desinfiziert wird. Dieses Übertragungsrisiko ist bei einer endokavitären Sonde, die mit der Vagina, dem Analkanal oder der Mundhöhle in Kontakt gekommen ist, erhöht, da diese mit Organismen kontaminiert sein könnte, die durch Blut oder durch Schleimhaut-, Genital- oder Rektalsekrete übertragen werden. Auf der Grundlage des Spaulding-Klassifikationssystems werden Schallköpfe, die mit Schleimhäuten in Kontakt kommen, als semikritische Geräte eingestuft, die nach jedem Patienteneingriff ein High-level-Desinfektionsverfahren (HLD) erfordern. Dieses HLD-Verfahren sollte alle Mikroorganismen mit Ausnahme vieler bakterieller Endosporen eliminieren. Nur wenige Länder weltweit haben Richtlinien für die Aufbereitung von Schallköpfen eingeführt, die sich an die Spaulding-Klassifikation halten und HLD für endokavitäre Sonden empfehlen. Insgesamt besteht unter den globalen Gesundheitsbehörden ein Mangel an Konformität hinsichtlich des Einsatzes der HLD für endokavitäre Sonden. Dies ist in erster Linie auf die Auffassung zurückzuführen, dass das Risiko der Infektionsübertragung vernachlässigbar ist und dass, wenn eine endokavitäre Sonde für den Eingriff mit einer Einweghülle abgedeckt wurde, eine Desinfektion auf niedrigem Niveau einen ausreichenden Schutz gegen die Übertragung von Krankheitserregern bietet. Das Ziel dieser Studie war es, Publikationen zum Risiko der Infektionsübertragung durch endokavitäre Sonden zu überprüfen. Indem wir die Ausbrüche und Fallberichte hervorheben, die eine Erregerübertragung durch Schallköpfe nahelegen, stellen wir fest, dass HLD weltweit Praxisstandard für die Aufbereitung von endokavitären Sonden werden sollte. Die Entwicklung und Verabschiedung neuer Empfehlungen durch die nationalen Gesundheitsbehörden sowie die Akzeptanz und Umsetzung von praktischen Änderungen bei Gesundheitsdienstleistern erfordern einen erheblichen Zeitaufwand. Wir empfehlen, dass die Joint Commission International (JCI) und andere gleichwertige Organisationen während ihrer Akkreditierungsprüfungen den Einsatz der HLD bei endokavitären Ultraschallsonden einfordern.

Key words

ultrasound - infection control - transducers/probes - reprocessing

Publication History

Received: 12 September 2019

Accepted: 14 April 2020

Article published online:
30 July 2020

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