Medical Devices Safety Update, Volume 4, Number 4, July 2016

5 July 2016

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

TGA tests resolve potential issue with intravenous catheter connection

Following an adverse event report, the TGA undertook tests on a needleless plastic valve, finding the likely cause of the reported issue and a simple way to resolve it.

The TGA received an adverse event report relating to a patient who was admitted for chemotherapy treatment via intravenous (IV) catheter. The report stated:

The patient's intravenous catheter was needled and the Neutron Needlefree Catheter Patency Device (NCPD) applied (as per policy) to the intravenous catheter needle set. The line was flushed with normal saline and flushed easily at this point.

The patient required premedications prior to treatment, but these could not be administered due to resistance in the line. The intravenous catheter was checked for correct positioning and the clamps were checked that they were unclamped.

The IV access above the valve on the intravenous catheter needle was flushing well so it appeared that the valve was faulty. The valve was replaced but the replacement also offered resistance to infusion, so it too was replaced.

The third valve worked correctly and all the treatment was administered as prescribed.

The reporter said this was not an isolated incident and other nurses at the facility had reported similar experiences with Neutron NCPDs recently.

About the device

The Neutron NCPD (sometimes referred to as 'Neutron valve') is a small, sterile, standalone Luer-activated needleless plastic valve. It is intended to mate two related IV line devices (for example, hypodermic syringe and catheter port or tubing from an IV administration set) and hold them in a secured, sealed, locked position until disconnection, at which point there is minimal fluid flow into or out of the catheter/tubing. It is intended to eliminate the use of needles for IV administration of medications.

The design of the Neutron NCPD is such that an internal silicone seal must be pushed, by the Luer lock taper on a syringe, past holes in a central spike. If this does not occur, then the NCPD will either restrict flow significantly or prevent it completely. The TGA hypothesised that stochastic variation in the NCPD and/or the Luer lock connectors in syringes and extension lines may lead to partial or complete blockage at the NCPD in a proportion of cases, even when assembled correctly.

How we tested

To avoid operator variation, valves were assembled onto fluid lines using a specially made apparatus that applies an axial force not exceeding 27.5 Newtons (N) while applying a torque not exceeding 0.12 Newton metres (Nm) as required by clause 5.2 in International Standard ISO 594-2:1998 prior to leak testing.

The assembled lines were connected to a peristaltic pump delivering 18 ml/min of water while monitoring the pressure drop across the assembly, an abnormally high pressure drop indicating that the line was blocked or partly occluded.

Figure 1 - Pressure drop across 101 Neutron NCPDs
Figure 1 - Pressure drop across 101 Neutron NCPDs

Visual inspection prior to each test did not identify any mechanical malfunctions in the 101 Neutron NCPDs tested. Fluid flow was established in every instance and there was no leakage from the connectors.

Test results showed the average pressure drop across the assemblies at 18 ml/min was 2.8 kPa. Two NCPDs displayed slightly elevated pressures (4.4 kPa), one displayed a moderately elevated pressure (6.2 kPa) and one valve displayed a significantly elevated pressure (8.2 kPa).

Whether elevated pressures of this magnitude are noticeable to a health professional depends on several factors such the size of syringe being used for priming or infusion and, if a syringe is not being used, the setting of any overpressure alarm. The problem is more noticeable when using a large bore (>20 ml syringe) syringe.

In every instance the restriction to flow was resolved if the valve was manipulated by slight tightening or loosening (so that the silicone seal cleared the central spike in the NCPD).

Conclusions

The TGA confirmed that it was possible that a proportion of Neutron NCPDs could block or partially restrict the flow when assembled normally. During our tests the incidence of occurrence was 4% of uses, but the problem was easily resolved by a slight tightening of the connection at the Neutron NCPD.

The TGA will work with the device sponsor to incorporate advice about the issue and its resolution in the Instructions for Use or in other material supplied by the manufacturer about the device.

Recent safety alerts

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

Medtronic deep brain stimulation therapy DBS Extension models 7483 and 37086: Hazard alert - risk of adverse events related to DBS tunnelling procedure

Medtronic deep brain stimulation devices - multiple models: Hazard alert - risk of loss of coordination in patients' movements

Ethicon Physiomesh Flexible Composite Mesh: Hazard alert - higher rate of recurrence/reoperation

Zimmer Biomet Trabecular Metal knee implant components: Hazard alert - potential for post-operative infection

Medtronic RestoreSensor implantable neurostimulators: Hazard alert - potential for loss of therapeutic effect due to battery charging issues

TRUEresult blood glucose test strips: Recall - risk of undetected high blood sugar levels due to incorrect readings

HeartWare external controller: Hazard alert - risk of problems due to loose power or data connectors

Birmingham Hip Modular Head (used in hip replacements): Update - new hazard alert with updated revision rates

Birmingham Hip Resurfacing system: Update - new hazard alert with updated revision rates

Silimed medical devices (all - including breast implants): Update - Extension to suspension

Military Trauma and Haemorrhage Wound Dressing: Recall - may break during use

Practice Points: The 'doctor's bag'

A doctor's bag will sometimes be stored in challenging conditions and the TGA encourages doctors to consider the effects this may have on medical devices.

Access to a doctor's bag is an important requirement for many doctors, including general practitioners.1 There is a large amount of literature available discussing the choice, use and maintenance of medications within a doctor's bag. However, there is little discussion regarding the correct storage and maintenance of medical devices within a modern doctor's bag.

Although the content of the bag may vary, a number of medical devices are commonly included in doctors' bags, such as:

  • auriscope
  • disposable gloves
  • equipment for maintaining an airway in both adults and children
  • ophthalmoscope
  • sharps container
  • sphygmomanometer
  • stethoscope
  • syringes and needles in a range of sizes
  • thermometer
  • tongue depressors
  • alcohol swabs
  • contaminated waste bags
  • hand sanitiser
  • blood glucose monitoring kit.

The TGA has received reports of changes to the pliability of plastic in resuscitation equipment used in doctors' bags. One potential cause of this is due to plastic degrading due to raised temperatures during vehicle storage.2

Points to consider

  • Disposable gloves: The shelf-life of gloves can be significantly reduced when exposed to temperatures above 30°C. This environmental storage requirement will vary depending on the brand of glove and can be found either printed on the box or from the manufacturer.
  • Diabetes test strips: Ensure containers holding test strips are sealed and be alert to the potential effects of high temperatures. Out of date and out of specification test strips are commonly seen and may lead to inaccurate or unobtainable results.
  • Resuscitation equipment: Bag and mask resuscitator devices have storage environmental temperature limits, with most devices stating an upper limit of +60°C.
  • Hand sanitiser products: Increasing temperatures can lead to decrease in efficacy. Many products state they should be stored below 25°C.
  • Syringes and needles: Expiry dates are printed on each packet. After this time, the sterility of the device may be compromised.
  • Equipment that requires calibration or that is electrically or battery operated requires regular servicing in accordance with the manufacturer's instructions.
  • Dust is known to impact on the function of many medical devices. Ensure that devices are cleaned regularly and stored in bags/boxes that may reduce dust accumulation.
  • Each piece of equipment will have a specific Instruction for Use document or product information that provides details of the storage and maintenance requirements.

TGA recommendations

The TGA advises health professionals to:

  • be alert to the potential for environmental conditions to affect the quality, safety and performance of medical devices
  • consider what environmental conditions affect the storage of your doctor's bag
  • take appropriate action to mitigate risks, including avoiding storing bags in vehicles for long periods and regularly replacing equipment to avoid degradation
  • familiarise yourselves with the Instructions for Use for medical devices that you use and be alert to references to the potential effects of environmental conditions, storage and maintenance
  • report issues with medical devices to the sponsor and/or TGA.

References

  1. Royal Australian College of General Practitioners (RACGP) Standards for General Practices 4th edition.
  2. Medical Devices Safety Update, Volume 3, Number 4, July 2015.

Adverse event reporting compliance

The TGA actively monitors sponsors' compliance with regulations - particularly those that relate to conditions of inclusion on the Australian Register of Therapeutic Goods - and will take action when these conditions are not complied with.

Sponsors of products on the Australian Register of Therapeutic Goods (ARTG) have a range of obligations under the Therapeutic Goods Act (the Act), including a requirement to report adverse events associated with their products.

In recent months the TGA has undertaken action in connection to two separate sponsors and their inadequate adverse event reporting.

In one case TGA monitoring found that one medical device sponsor was failing to report adverse events. The sponsor's standard operating procedures did not comply with relevant subsections of the Act. The adverse event and complaint data provided by the sponsor demonstrated discrepant results and indicated non-reporting of adverse events.

The TGA has imposed an additional condition on two of the sponsor's ARTG entries. This condition states that the sponsor must provide the TGA with all adverse event reports and complaints that have occurred in Australia within 10 working days of them being lodged for a minimum of two years unless the sponsor assesses that the adverse event meets the criteria for reporting within a shorter time frame. In the other case, the TGA identified that the sponsor of a medicine being used in a clinical trial was reporting the required adverse events, but not in a timely manner. The TGA raised the issue with the sponsor who responded that they had believed they were acting according to requirements, but agreed to improve their reporting timeframes.

What to report? Please report adverse events, as well as near misses

The TGA encourages the reporting of any suspected adverse event or potential adverse event relating to a medical device. Adverse events can involve actual harm to a patient or caregiver, or a near miss that may have resulted in harm.

Some issues relating to medical devices that may lead to adverse events and prompt you to report include:

  • mechanical or material failure
  • design issues
  • labelling, packaging or manufacturing deficiencies
  • software deficiencies
  • device interactions
  • user/systemic errors.

Suspected adverse events or near misses can be reported directly to the TGA:

For more information about reporting, visit www.tga.gov.au or contact the TGA's Medical Devices Branch on 1800 809 361.

Disclaimer

The Medical Devices Safety Update (MDSU) is aimed at health professionals and is intended to provide practical information on medical device safety, including emerging safety issues. The information in the MDSU is necessarily general and is not intended to be a substitute for a health professional's judgment in each case, taking into account the individual circumstances of their patients. Reasonable care has been taken to ensure that the information is accurate and complete at the time of publication. The Therapeutic Goods Administration gives no warranty that the information in this document is accurate or complete, and does not accept liability for any injury, loss or damage whatsoever, due to negligence or otherwise, arising from the use of or reliance on the information provided in this document.

© Commonwealth of Australia 2016

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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: Ms Pamela Carter

Deputy Editor: Mr Aaron Hall

Acting TGA Principal Medical Adviser: Dr Tony Gill

Contributors include: Dr Cate Brogan and Dr Jorge Garcia