Medical Devices Safety Update, Volume 3, Number 5, September 2015

Medical Devices Safety Update is the medical device safety bulletin of the Therapeutic Goods Administration (TGA)

Check 'synch' before cardioversion

Health professionals are reminded of the importance of ensuring a defibrillator is in synchronised ('synch') mode before undertaking cardioversion therapy.

Cardioversion is the process of restoring the heart's normal rhythm by applying a controlled electric shock to the exterior of the chest. It is used to treat arrhythmias (abnormal rhythm).

Due to the potential for unsynchronised shocks to create life-threatening arrhythmia (e.g. ventricular fibrillation (VF)), it important for health professionals to ensure devices are in 'synch' mode before undertaking cardioversion.

Potential for unsynchronised shocks

The TGA has received two adverse event reports since January 2014 of devices displaying irregular behaviour during 'synch' events. In such situations there is increased potential for unsynchronised shocks to be delivered if the issue is not identified early. In both cases the issue was identified and neither incident resulted in patient injury.

Whether a device is in 'synch' mode is usually indicated on the display and it is recommended to check more than once to confirm prior to delivery of therapy.

Operators need to know each device's settings and behaviour before undertaking cardioversion therapy. It is also important to understand if the individual defibrillator is set to remain in 'synch' mode after a shock is given.

Devices will not start in 'synch' mode, so cycling (turning machine off then on) the power when problems occur can return the device to asynchronous, or VF shock, mode.

Consider internal policies

Health facilities and health professionals are advised to carefully consider their internal policies regarding defibrillator settings. Depending on these settings, in situations where synchronisation therapy fails after the first shock, the device may revert to unsynchronised mode. The next shock has some potential to create life-threatening arrhythmia, which would need a third shock to treat.

It is preferable to ensure all devices are the same and behave the same (i.e. have the same settings) within each health facility.

The clinical implications of keeping devices in 'synch' mode after shock delivery should be considered during set-up and training. Synch mode settings or the performance of the defibrillator can be affected in the rare event that the 'synch' circuit fails. If this happens, the shock may also cause life-threatening arrhythmia, which again could need a follow-up shock to treat.

Facility managers should ensure that users have read and understand the Instructions for Use before using any defibrillator and/or receiving training on the use of the defibrillator. Where any doubt exists regarding the operation of 'synch' mode, consult senior clinical staff, the facility biomedical engineering department or the device manufacturer.

Recognising medical device incidents

While some medical device incidents (also known as adverse events) are obvious, the definition of what constitutes one is broader than many may imagine.

Previously in Medical Devices Safety Update (MDSU), the TGA has provided information on its IRIS inSite program - a pilot project to support reporting of medical device incidents in hospitals. The key messages for the project are 'Recognise', 'Retain' and 'Report'.

An article focusing on 'Retain' was published in the May 2015 issue of MDSU, while this article will explore the 'Recognise' component of medical device incident reporting.

Defining medical devices

The different types of medical devices range from the very simple, such as tongue depressors, gauze pads and bandages, through to the most complex and sophisticated monitoring and medical imaging equipment.

Examples include:

• single-use devices - staplers, cannulas and catheters
• reusable devices, such as surgical instruments
• implantable devices - pacemakers, intraocular lenses and joint replacements
• equipment, such as wheelchairs, beds, pumps and sterilisers
• in vitro diagnostics
• software, which is an increasingly important component of many devices
• consumables, such as scrub solutions and skin preps
• components, such as connectors, filters and lines.

Defining medical device incidents

There is a similarly broad definition of what constitutes a medical device incident.

Incidents are adverse events or potential adverse events (sometimes called 'near misses') resulting from the use of a medical device. They are unintended and can be experienced by any user, including a patient, caregiver or health professional.

Examples include:

• mechanical or material failure of a device - it breaks during normal use
• failure of a software upgrade, which creates new problems
• overly complex or substandard design or construction which creates a safety risk for patients or health professionals
• labelling or packaging inadequacies
• Instructions For Use which are unclear or incomplete
• failed interactions between connected devices
• design so poor that it makes it difficult to use the product as it is intended
• design which means it is difficult or impossible to clean or sterilise a reusable device to an acceptable standard.

The TGA is interested in reports of near misses as well as actual events. If you can identify that there is a risk associated with a medical device, you don't have to wait for an incident to happen to report your observations.

Reporting is easy and there are various avenues for doing it, including a convenient online reporting form located on the TGA webpage. If a problem has occurred with a product multiple times, you can lodge all those reports in one online report.

Details of other methods of medical device incident reporting are available on the TGA's 'Report a problem' webpage.

Risks to health professionals, ancillary workers, visitors and patients are all just as important as each other, and they are all reportable.

What happens to your report?

Every report provided to the TGA is entered into a database and logged against the medical device's Australian Register of Therapeutic Goods entry.

When deciding which reports to investigate, the TGA's Incident Reporting and Investigation Scheme (IRIS) team look for the combined effect of frequency and severity of risk.

An event which happens once and has a relatively low risk may not be investigated on that occasion. However, the data remains logged against that device, and if sufficient reports are received, an investigation will be instigated. Conversely, a single incident with a severe outcome or risk will likely be investigated immediately.

The volume and quality of reports are hugely important to the TGA in building a databank of information that is statistically significant and current.

Medical device incidents reported to the TGA can lead to actions such as product recalls, safety alerts, product improvement, user education and compliance testing.

If you would like further information or advice on lodging a medical device incident report, please call 1800 809 361 during business hours or email iris@tga.gov.au.

Grounding pad selection vital during electrosurgical and ablation procedures

With an increasing number of 'non-traditional' electrosurgical and ablation procedures being undertaken, health professionals are reminded of the importance of selecting and using grounding pads correctly.

A recent adverse event reported to the TGA, citing a case where a patient had received serious burns at the grounding pad site during a cardiac ablation, offers a reminder of the importance of complying with electrosurgical safety guidelines during procedures using grounding, or return, pads.

There is an increasing number of 'non-traditional' procedures - ablations, tissue lesioning, tissue vaporisation, etc - for which the grounding pad requirements are different to those used for traditional surgical diathermy procedures.
'Non-traditional' procedures may utilise high currents, long duty cycles, or both, making them higher risk than traditional diathermy.

Key issues

Health professionals are advised to be mindful of the following:

• Ensure the grounding pad is appropriate to the specific generator being used - there is no 'one size fits all' solution.
• Read and follow the relevant section of the Instructions for Use (IFU) of the electrical current generator being used and be familiar with the guidelines for that product.
• Take into account the individual patient's requirements, for example paediatric patients, obese patients and patients with piercings or surgical implants may have particular needs.
• Procedures in which conductive fluids such as saline or lactated Ringer's solution are introduced into the surgical site, for distention or to conduct the radiofrequency current, increase the risk of excessive heating under a fully applied return.
• In some circumstances it may be appropriate to use more than one grounding pad.

Seek information

Apart from the IFU for the particular generator being used, suppliers and facility biomedical engineering departments are good sources of information on how best to keep patients safe while using electrical energy in their treatment.

Practice points - HIV point-of-care testing

In an effort to prevent adverse events, Medical Devices Safety Update from time to time highlights some important clinical practice points to facilitate the safe use of certain devices.

Human immunodeficiency virus (HIV) point-of-care tests are used to screen for HIV outside the laboratory setting.

The TGA had received a total of four adverse event reports for HIV point-of-care tests up until April 2015. These included three false positive results.

Although the rate of false positive results appears to be within the expected range, the TGA advises health professionals to consider some important clinical practice points when using HIV point-of-care tests.

Hypothetical clinical scenario

A patient presents with a positive HIV nucleic acid amplification testing (NAAT) result in the context of recent symptoms consistent with an HIV seroconversion illness. The patient is tested during the consultation using an HIV point-of-care test. A negative or non-reactive result is received

Practice points - the role of HIV point-of-care testing

The following issues should be considered when using HIV point-of-case testing:

• While point-of-care tests can provide rapid results, they are a preliminary screen only. In other words, the test is not used as a diagnostic test for HIV.
• As with all screening tests, the HIV point-of-care tests are expected to have a high level of sensitivity but false negatives can occur if testing is performed during the early stages of infection. The level of antigen and antibody may not be detectable within the first three months of infection and false negative results can be obtained during this period. Therefore, negative results also require interpretation to take into account the patient's individual circumstances.
• Where clinical presentation (such as symptoms consistent with acute seroconversion illness) or other data would suggest that a screening test is not appropriate, or an inconsistent result is received, the patient should be tested by a diagnostic laboratory test immediately.
• Although HIV point-of-care tests also have a high level of specificity, it is expected that a low rate of false positive results will still occur, particularly when testing is performed in low prevalence populations. Sensitivity, specificity and other issues relating to testing were discussed in more detail in the March 2014 edition of MDSU.
• All positive results require confirmation by a diagnostic laboratory test.
• HIV point-of-care tests should always be used according to the IFU documentation.

More information

• HIV testing in Australia
• Clinical performance requirements and risk mitigation strategies for HIV tests

Recent safety alerts

Below are TGA safety alerts relating to medical devices published since the last edition of Medical Devices Safety Update.

Profemur cobalt-chrome femoral neck: Hazard alert - potential for component failure due to metal fracture

Vertical Expandable Prosthetic Titanium Rib caudal rib supports: Hazard alert - risk of implant breakage

Contact Detach infusion sets: Recall for product correction - potential for interruption of medicine delivery and/or infection due to needle breaking during use

Medtronic neurostimulators used for deep brain stimulation therapy: Hazard alert - warnings regarding potential adverse events

MiniMed 640G insulin pump: Recall for product correction - potential for user error leading to incorrect dosing

Clinect Neria infusion sets: Recall for product correction - potential for interruption of medicine delivery and/or infection due to needle breaking during use

Disclaimer

For the latest information from the TGA, subscribe to the TGA Safety Information email list.

For correspondence or further information about Medical Devices Safety Update, contact the TGA's Medical Devices Branch at iris@tga.gov.au or 1800 809 361.

Medical Devices Safety Update is written by staff from the Medical Devices Branch.

Editor: Dr Pamela Carter

Deputy Editor: Mr Aaron Hall

Acting TGA Principal Medical Adviser: Dr Tony Gill

Contributors include: Dr Cate Brogan, Mr Shawn Hazel, Mr Patrick O'Meley, Ms Jan Law