SonoGuidelines : AIUM guidelines for cleaning probes (external and internal) #FOAMus

In an official statement by the American Institute of Ultrasound in Medicine (AIUM), they updated their guidelines on cleaning probes: Read below:

“The purpose of this document is to provide guidance regarding the cleaning and preparation of external and internal ultrasound probes. Some manufacturers use the term “transducers” or “imaging arrays.”

Medical instruments fall into different categories with respect to their potential for pathogen transmission. The most critical instruments are those that are intended to penetrate skin or mucous membranes. These require sterilization. Less critical instruments (often called “semicritical” instruments) that simply come into contact with mucous membranes, such as fiber-optic endoscopes, require high-level disinfection rather than sterilization. “Noncritical” devices come into contact with intact skin but not mucous membranes.

External probes that only come into contact with clean, intact skin are considered noncritical devices and require cleaning after every use as described below.

All internal probes should be covered with a single-use barrier. If condoms are used as barriers, they should be nonlubricated and nonmedicated. Although internal ultrasound probes are routinely protected by single-use disposable probe covers, leakage rates of 0.9% to 2% for condoms and 8% to 81% for commercial probe covers have been observed in recent studies (Rutala and Weber, 2011). These probes are therefore classified as semicritical devices.

Note: Practitioners should be aware that condoms have been shown to be less prone to leakage than commercial probe covers and have a 6-fold enhanced acceptable quality level (AQL) when compared to standard examination gloves. They have an AQL equal to that of surgical gloves. Users should be aware of latex sensitivity issues and have non-latex-containing barriers available.

For maximum safety, one should therefore perform high-level disinfection of the probe between each use and use a probe cover or condom as an aid to keep the probe clean. For the purpose of this document, “internal probes” refer to all vaginal, rectal, and transesophageal probes, as well as intraoperative probes and all probes that are in contact with bodily fluids/blood or have a remote chance to be in contact with dry/cracked skin and body fluids, including blood.

Definitions

All cleaning, disinfection, and sterilization represent a statistical reduction in the number of microbes present on a surface rather than their complete elimination. Meticulous cleaning of the instrument is the key to an initial reduction of the microbial/organic load by at least 99%. This cleaning is followed by a disinfecting procedure to ensure a high degree of protection from infectious disease transmission, even if a disposable barrier covers the instrument during use.

According to the Centers for Disease Control and Prevention (CDC) “Guideline for Disinfection and Sterilization in Healthcare Facilities” (2008):

Cleaning is the removal of visible soil (eg, organic and inorganic material) from objects and surfaces and normally is accomplished manually or mechanically using water with detergents or enzymatic products. Thorough cleaning is essential before high-level disinfection and sterilization because inorganic and organic material that remains on the surfaces of instruments interfere with the effectiveness of these processes.”

Disinfection describes a process that eliminates many or all pathogenic microorganisms, except bacterial spores.”

Low-Level Disinfection—Destruction of most bacteria, some viruses, and some fungi. Low-level disinfection will not necessarily inactivate Mycobacterium tuberculosis or bacterial spores.

Mid-Level Disinfection—Inactivation of M Tuberculosis, bacteria, most viruses, most fungi, and some bacterial spores.

High-Level Disinfection—Destruction/removal of all microorganisms except bacterial spores.

Sterilization describes a process that destroys or eliminates all forms of microbial life and is carried out in healthcare facilities by physical or chemical methods. Steam under pressure, dry heat, ethylene oxide (EtO) gas, hydrogen peroxide gas plasma, and liquid chemicals are the principal sterilizing agents used in health-care facilities. . . . When chemicals are used to destroy all forms of microbiologic life, they can be called chemical sterilants. These same germicides used for shorter exposure periods also can be part of the disinfection process (ie, high-level disinfection).”

The following specific recommendations are made for the cleaning and preparation of all ultrasound probes. Users should also review the CDC document on sterilization and disinfection of medical devices to be certain that their procedures conform to the CDC principles for disinfection of patient care equipment.

1. Cleaning—Transducers should be cleaned after each examination with soap and water or quaternary ammonium (a low-level disinfectant) sprays or wipes. The probes must be disconnected from the ultrasound scanner for anything more than wiping or spray cleaning. After removal of the probe cover (when applicable), use running water to remove any residual gel or debris from the probe. Use a damp gauze pad or other soft cloth and a small amount of mild nonabrasive liquid soap (household dish-washing liquid is ideal) to thoroughly cleanse the probe. Consider the use of a small brush, especially for crevices and areas of angulation, depending on the design of the particular probe. Rinse the probe thoroughly with running water, and then dry the probe with a soft cloth or paper towel.

2. Disinfection—As noted above, all internal probes (eg, vaginal, rectal, and transesophageal probes) as well as intraoperative probes require high-level disinfection before they can be used on another patient.

For the protection of the patient and the health care worker, all internal examinations should be performed with the operator properly gloved throughout the procedure. As the probe cover is removed, care should be taken not to contaminate the probe with secretions from the patient. At the completion of the procedure, hands should be thoroughly washed with soap and water. Gloves should be used to remove the probe cover and to clean the probe as described above.

Note: An obvious disruption in condom integrity does not require modification of this protocol. Because of the potential disruption of the barrier sheath, high-level disinfection with chemical agents is necessary. The following guidelines take into account possible probe contamination due to a disruption in the barrier sheath.

After removal of the probe cover, clean the transducer as described above. Cleaning with a detergent/water solution as described above is important as the first step in proper disinfection, since chemical disinfectants act more rapidly on clean and dry surfaces. Wet surfaces dilute the disinfectant.

High-level liquid disinfection is required to ensure further statistical reduction in the microbial load. Examples of such high-level disinfectants are listed in Table 1. A complete list of US Food and Drug Administration (FDA)-cleared liquid sterilants and high-level disinfectants is available at http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm194429.htm, and other agents are under investigation.

To achieve high-level disinfection, the practice must meet or exceed the listed “High-Level Disinfectant Contact Conditions” specified for each product. Users should be aware that not all approved disinfectants on this list are safe for all ultrasound probes.

The CDC recommends environmental infection control in the case of Clostridium difficile, consisting of “meticulous cleaning followed by disinfection using hypochlorite-based germicides as appropriate” (CDC, 2008). The current introduction and initial marketing of a hydrogen peroxide nanodroplet emulsion might provide an effective high-level disinfectant without toxicity.

Table 1. Sterilants and High-Level Disinfectants Listed by the FDA

Name Composition/Action
Glutaraldehyde Organic compound (CH2(CH2CHO)2)
Induces cell death by cross-linking cellular proteins; usually used alone or mixed with formaldehyde
Hydrogen peroxide Inorganic compound (H2O2)
Antiseptic and antibacterial; a very strong oxidizer with oxidation potential of 1.8 V
Peracetic acid Organic compound (CH3CO3H)
Antimicrobial agent (high oxidization potential)
Ortho-Phthalaldehyde Organic compound (C6H4(CHO)2)
strong binding to outer cell wall of contaminant organisms
Hypochlorite/hypochlorous acid inorganic compound (HClO)
Myeloperoxidase-mediated peroxidation of chloride ions
Phenol/phenolate Organic compound (C6H5OH)
Antiseptic
Hibidil Chlorhexidine gluconate (C22H30Cl2N10)
Chemical antiseptic

The Occupational Safety and Health Administration as well as the Joint Commission (Environment of Care Standard IC 02.02.01 EP 9) have issued guidelines for exposure to chemical agents, which might be used for ultrasound probe cleaning. Before selecting a high-level disinfectant, users should request the Material Safety Data Sheet for the product and make sure that their facility is able to meet the necessary conditions to minimize exposure (via inhalation, ingestion, or contact through skin/eyes) to potentially dangerous substances. Proper ventilation, a positive-pressure local environment, and the use of personal protective devices (eg, gloves and face/eye protection) may be required.

Immersion of probes in fluids requires attention to the individual device’s ability to be submerged. Although some scan heads as well as large portions of the cable may safely be immersed up to the connector to the ultrasound scanner, only the scan heads of others may be submerged. Some manufacturers also note that the crystals of the array may be damaged if, instead of suspending the probe in the disinfectant, it rests on the bottom of the container. Before selecting a method of disinfection, consult the instrument manufacturer regarding the compatibility of the to-be-used agent with the probes. Relevant information is available online and in device manuals. Additionally, not all probes can be cleaned with the same cleaning agents. Although some agents are compatible with all probes of a given manufacturer, others must be limited to a subset of probes.

After soaking the probe in an approved disinfectant for the specified time, the probe should be thoroughly rinsed (especially to remove traces of toxic disinfectants in the case of ortho-phthalaldehyde) and dried.

Summary

Adequate probe preparation is mandatory. The level of preparation depends on the type of examination performed. Routine high-level disinfection of internal probes between patients is mandatory, plus the use of a high-quality single-use probe cover during each examination is required to properly protect patients from infection. It would be reassuring for the user to be able to consult manufacturer’s instructions, particularly those that have been validated by the manufacturer for sterilizing devices. Preparation of external probes between patients is less critical and reduced to a low-level disinfection process. For all chemical disinfectants, precautions must be taken to protect workers and patients from the toxicity of the disinfectant.

The AIUM does not endorse or promote any specific commercial products. It is the responsibility of each entity to follow the manufacturer’s guidelines, law, and regulations.

Suggested Reading

  1. Amis S, Ruddy M, Kibbler CC, Economides DL, MacLean AB. Assessment of condoms as probe covers for transvaginal sonography. J Clin Ultrasound 2000; 28:295-298.
  2. Bloc S, Garnier T, Bounhiol C, et al. Ultrasound-Guided Regional Anaesthesia: An Effective Method for Cleaning the Probes. Quincy-Sous-Sénart, France: Service d’Anesthésie, Hôpital Privé Claude-Galien; 2010.
  3. Centers for Disease Control and Prevention, Hospital Infections Program. National Nosocomial Infections Surveillance (NNIS) report, data summary from October 1986-April 1996: a report from the NNIS system. Am J Infect Control 1996; 24:380-388.
  4. Frazee BW, Fahimi J, Lambert L, Nagdev A. Emergency department ultrasonographic probe contamination and experimental model of probe disinfection. Ann Emerg Med 2011; 58:56-63.
  5. Hignett M, Claman P. High rates of perforation are found in endovaginal ultrasound probe covers before and after oocyte retrieval for in vitro fertilization-embryo transfer. J Assist Reprod Genet 1995; 12:606-609.
  6. Kac G, Podglajen I, Si-Mohamed A, Rodi A, Grataloup C, Meyer G. Evaluation of Ultraviolet C for Disinfection of Endocavitary Ultrasound Transducers Persistently Contaminated Despite Probe Covers. Paris, France: Hygiène Hospitalière; 2010
  7. Koibuchi H, Fujii Y, Kotani K, et al. Degradation of ultrasound probes caused by disinfection with alcohol. J Med Ultrason 2011; 38:97-100.
  8. Milki AA, Fisch JD. Vaginal ultrasound probe cover leakage: implications for patient care. Fertil Steril 1998; 69:409-411.
  9. Mirza WA, Imam SH, Kharal MS, et al. Cleaning methods for ultrasound probes. J Coll Physicians Surg Pak 2008; 18:286-289.
  10. Muradali D, Gold WL, Phillips A, Wilson S. Can ultrasound probes and coupling gel be a source of nosocomial infection in patients undergoing sonography? An in vivo and in vitro study. AJR Am J Roentgenol 1995; 164:1521-1524.
  11. Rooks VJ, Yancey MK, Elg SA, Brueske L. Comparison of probe sheaths for endovaginal sonography. Obstet Gynecol 1996; 87:27-29.
  12. Rutala WA, Weber DJ. Sterilization, high-level disinfection, and environmental cleaning. Infect Dis Clin North Am 2011; 25:45-76.
  13. Whitehead EJ, Thompson JF, Lewis DR. Contamination and decontamination of Doppler probes. Ann R Coll Surg Engl 2006; 88:479-481.

Related Websites

  1. US Food and Drug Administration. Cleared liquid chemical sterilants/high-level disinfectants US FDA website; March 03, 2010. http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm194429.htm.
  2. Centers for Disease Control and Prevention. Guideline for disinfection and sterilization in healthcare facilities, 2008. Centers for Disease Control and Prevention website; 2008. http://www.cdc.gov/hicpac/pdf/guidelines/Disinfection_Nov_2008.pdf.
  3. Occupational Safety and Health Administration. Hospital eTool: clinical services. Occupational Safety and Health Administration website. http://www.osha.gov/SLTC/etools/hospital/clinical/pt/pt.html.

SonoNews: Robotic arm allows remote real-time ultrasound scans -made by French engineers

Now, this is pretty cool. Imagine doing an ultrasound on someone who is not right where you are, but could be in another hospital, or maybe even in another country? These french engineers has made something that is almost to that level. Read below for the EDMT medical imaging article:

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“In a breakthrough that might expand the frontiers of ultrasound examinations, a French company has developed the world’s first industrial-scale remote ultrasound system with a robot arm.

Introduced for radiography, remote imaging is now also used for ultrasound, which accounts for one third of medical imaging procedures, making it the most common such procedure in medicine. Today, ultrasound is the most efficacious of all diagnostic procedures, and on average costs half as much as CT scanning. However, medical exams during pregnancy and detailed investigations of organs, blood vessels, ligaments and the heart require the presence of a highly trained physician at the patient’s bedside as well as hands-on operation of the ultrasound device and interpretation of the resulting images.

Remote medical image scanning using a robot arm that functions as a genuine extension of the physician’s hand was invented by the head of the Department of Nuclear Medicine and Ultrasound at Tours University, Philippe Arbeille, as an outgrowth of manned space flight research that is supported by France’s CNES and by the ESA.

“The main challenge is to resolve the problem of synchronous video transmission. Also, the operator needs to be able to place his hand on the patient virtually,” notes AdEchoTech CEO Éric Lefebvre. The French company recently invested four years and one million Euros in the development of the world’s first industrial-scale remote ultrasound system. AdEchoTech has four patents pending for its Melody robot, two of them with Orleans University’s PRISME mechanical engineering research center.

AdEchoTech’s Melody workstation consists of two elements. For the medical practitioner, the workstation comprises a control box, a mini-console and a virtual probe that remotely controls the ultrasound probe arm. And on the patient side, the operator controls the probe arm remotely. The ultrasound probe, connected to the ultrasound device, is attached to the extremity of the robot arm, whose load is lightened by the arm’s carrier base while at the same time making the arm very easy to manipulate. Thanks to its modularity, the solution is readily adaptable to any given technical environment. Particularly, since operator and patient stations can be operated via satellite, as well as fiber optic 3G+ and 4G hookups. In this regard, the system is compatible with most commercially available ultrasound and video conferencing systems.

“Our R&D also focused on compression algorithms, so as to allow for the communication of information concerning the transmission of ultrasound images, as well as for control of the robot arm and for the realization of video conferences in real time – and all of this in a merely 2 Mbit/s symmetrical bandwidth,” says an AdEchoTech engineer.

The Melody robot, which obtained the CE mark in 2012, allows for 90% concordance with conventional ultrasound, and is useful for solving the growing problems entailed by the performance of ultrasound examinations on islands, in mountainous regions, and on ships or oil drilling platforms, in military zones, for repatriation medicine, and in prisons. Ten Melody stations are already in operation in French hospitals, where they are used for the following procedures: pelvic and abdominal emergencies (investigations of the hepatobiliary system, the urinary system, the abdominal aorta and the pancreas) and examinations during pregnancy. In such settings, the system helps to avoid lengthy trips for pregnant women to major hospitals.

“A second generation of patented Melody robots will benefit from two additional degrees of movement freedom, which will allow for the performance of remote cardiac ultrasound examinations,” says Lefebvre. A third generation of Melody robots, which is expected to be available in 2017, will carry out remote robot-assisted ultrasound for punctures and certain surgical procedures.

By: Bernard Banga, MD Report, France

SonoEquipment: SonoSite’s new XPorte and their free teaching files on iTunes #FOAMed

SonoSite has launched a new ultrasound system called XPorte – it is an ultrasound machine and more! It’s all touch screen and not only allows for quick scanning and easy inputting of data, but it has lectures that you can view and listen to right there!

Screen Shot 2013-11-25 at 7.18.56 PM

You can download the free lectures and Xporte info from iTunes here. It’s another great resource for free ultrasound education. Hopefully SonoSite will not change that, but I doubt they will, as they already have a great app for free, called SonoAccess, as well as awesome online lecture tutorials by the best in the field in their online learning center.

SonoEquipment: How to make your own Ultrasound Gel – Guar gum, salt, and water #FOAMed

I saw an interesting blog post, sent to me by my ultrasound uncle, Dr. Chris Fox, that was on the: “Why Is American Healthcare so Expensive?” site entitled “How to Make Ultrasound gel: which is also sterile and edible and environmentally friendly” by Dr.Janice Boughton. Not only did the title catch my eye, but the content drew me even closer. If you are in need of gel – whether that’s because you are doing global health, disaster relief, or healthcare at any resource-limited area – there are ways to make it. Ive heard of a couple alternatives – and here is a way to make your own – that is also sterile, edible, and environmentally friendly. :)

As the blog post states: “Ultrasound requires an aqueous interface between the transducer and the skin or else all you see is black. Ultrasound gel is a clear goo, looks like hair gel or aloe vera, and is made by several companies out of various combinations of propylene glycol, glycerine, perfume, dyes, phenoxyethanol or carbapol R 940 polymer along with lots of water.” – not easy to find, and ot so cheap either. So, she set out and tried six different recipes – yup, that’s right – SIX! …and made the below gel (see pic) from guar gum (found in the flour section of stores), salt and water:

IMG_0075

“Guar gum is available in the flour section of many grocery stores and costs about $10 for a 220 gram bag. It is purported to be good for diarrhea, constipation, diabetes and lowering cholesterol.” – how cool is that?!

1. Mix 2 teaspoons of guar gum with 1-2 teaspoons of salt. (The amount of salt isn’t vitally important since it is just added to keep the guar gum from clumping. Using slightly less than a teaspoon of salt per 2 cups makes a gel with which is isotonic, which would be ideal for use near eyes or other mucus membranes or on open wounds).

2. Boil two cups of water.

3. Slowly sprinkle the guar gum/salt mixture into the boiling water while stirring vigorously with a fork or whisk.

4. Boil for about 1-2 minutes until thick and well mixed.

5. Cool before using. Save lives.

To read more about her plight – click here. Thanks Janice!

Below is a video on how to do it made by her too:

An Excerpt from LITFL today: a Cheap way to Make an US Simulator!

An excerpt from Life in the Fast Lane (LITFL): VERY cool US simulator that you can make cheaply!!! Just need hardware….The guys from Saskatchewan, Paul Kulyk and Paul Olszynski (http://www.edus2.com/) have developed a trainer for using in simulation which they explain very well in their project summary: “The Emergency Department Ultrasound Simulator (edus2TM) is a portable bedside ultrasound device that allows for the seamless integration of Emergency Department Ultrasound (EDUS) into high fidelity simulation scenarios (HFS). Trainees using the edus2 gain the opportunity to determine whether to use bedside ultrasound (indications), how to properly hold and place the probe (image generation) and finally how to assess scans (image interpretation) as displayed on the edus2 screen all within the context of an HFS scenario.”

SonoStuff: new and upcoming US equipment

Sonosite’s iPAD style US machine – coming soon! http://mobilehealthoutlook.com/?p=846GE’s hand-held Vscan is upgraded! better, fasterhttp://medgadget.com/2012/05/ge-upgrades-its-portable-vscan-ultrasound.html

Zonare’s faster software and improved image resolution:http://www.zonare.co.uk/products/

Phillips new Clearvue for improved Echocardiography:http://www.healthcare.philips.com/us_en/products/ultrasound/systems/clearvue550/