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Medical device incident investigations, March 2002

27 March 2002

Correct use of warming blankets

The TGA continues to receive reports of patient injuries associated with the inappropriate use of warming blankets. In addition, an article published in the Australian Operation Room Nurse Journal (AORN) this year, reports that patients have been injured by the use of hoses, rather than warming blankets being used as patient warming source. The hoses have not been attached to patient warming blankets and have either been placed on the patient directly or over a blanket draped over the patient. This practice has resulted in several burns to patients who required extended hospital stays and further treatment.

The reasons given for not using an appropriate warming blanket are generally that the practitioner believes that they are saving money and that any warming is good warming.

The TGA recommends that users become familiar with and strictly follow the patient warmer instructions for use and warnings when using blanket warmers, including the use of an appropriate patient warming blanket. "Hot spots" may develop in blankets, usually at the inlet port. Patients should be checked periodically to ensure that any hot spots are not in contact with the patient.

Maintenance of medical devices: minimisation of cross contamination

The TGA received a safety notice from the Medical Devices Agency (MDA) of the UK about the maintenance of medical devices to minimise the possibility of cross contamination.

The MDA has received an adverse event report in which it was found that the internal components of an intensive care ventilator were contaminated with Methicillin Resistant Staphylococcus Aureus (MRSA). This organism was found in dust that had accumulated on internal surfaces such as the circuit boards and in the air filters. Hospital staff were unaware of the need to clean/replace the filters, even though this information is contained in the manufacturers instructions for use.

The TGA would also like to remind users that certain parts of medical devices such as air filters can harbour infectious organisms if not cleaned correctly or replaced according to the manufacturers instructions for use. It is also important to note that users need to be aware of all instructions in the operations manual and put in place checks to ensure that these instructions are followed.

Paracentesis/thoracentesis kits

The TGA has received a Device Incident Report in relation to the death of a patient associated with the use of a thoracentesis device. During a pleural tap, the thoracentesis needle inadvertently entered the left ventricle, ultimately leading to the death of the patient as a result of cardiac tamponade. The risk of the event is not restricted to any one brand of this type of device.

The "Instructions for Use" states, "Caution: the introducer needle must be withdrawn as soon as fluid is observed in the 5 cc syringe to avoid potential damage to internal organs. Care must also be taken to avoid damaging internal organs with the catheter tip. The introducer needle should not be advanced in the catheter after it has been partially withdrawn."

The TGA would like to alert users to this potential risk and of the need for caution when undertaking such procedures.

High flow fluid infusers and air embolism

The TGA has received several reports of deaths or serious injury to patients due to intra-vascular air embolisms associated with the use of high-flow fluid infusers/fluid warmers. These devices are generally used in emergency situations.

It is believed that, in most of the incidents, the injury has resulted from re-attachment of partially exhausted fluid bags to the system. The bags contained significant volumes of air as a result of the handling and storage associated with detachment and re-attachment. This large volume of air is generally not present in a correctly handled fresh bag of solution when it is first attached to the infusion device.

After consultation with, and in cooperation with the TGA, all sponsors of these devices recently issued a Safety Alert to remind users of the risks of introducing air into these systems and the possible consequence of serious injury to patients connected to these systems.

In the interest of patient safety, when using these products it is essential to:

  • REMOVE ALL AIR from fluid bags and lines before connection to patients;
  • FOLLOW appropriate instructions for PRIMING the infusion line and set; and
  • MONITOR fluid lines to ensure that they are free of air.
  • DO NOT open ports in the infusion system, unless appropriate measures are in place to prevent the entry of air.
  • DO NOT reconnect partially emptied fluid bags - significant volumes of air may be sucked into the bag when disconnected.
  • DO NOT use auto-transfusion bags with these systems, unless the infuser is clearly indicated for this use.

Electrosurgery and patient return electrode burns

3M Australia Pty. Ltd., in cooperation with the TGA, recently issued a Safety Alert to inform users of 3M electrosurgical grounding plates of the risk to patients of burns at the patient return electrode during certain high power electrosurgical procedures. Patient injuries have been reported overseas, but no incidents have been reported in Australia.

The problem is potentially associated with any high power monopolar electrosurgical procedure. Monopolar electrosurgery typically uses high power, long activation periods and a distention/ irrigation medium. If the patient return electrode is not capable of dispersing this power level, a burn may result as the patient return electrode overheats.

The situation can sometimes be exacerbated if the distention/ irrigation medium is conductive (e.g. saline). This can disperse the therapeutic current. Under these circumstances, relatively high power is required to achieve the same surgical effect and an increasing demand is placed on the patient return electrode. This causes the electrode to get hot.

In the interest of patient safety, when performing monopolar electrosurgical procedures:

  • USE ADEQUATELY SIZED PATIENT RETURN ELECTRODES - it may sometimes be necessary to connect two such electrodes, particularly during procedures with high power settings and extended activation periods; and
  • AVOID the use of ELECTROLYTIC distention/irrigation MEDIA (e.g. saline) during monopolar surgery, if possible. Non-electrolytic media (e.g. sorbitol, glycine, dextran10) should decrease the power required to perform the procedure;
  • BE AWARE that some electrosurgical systems produce power levels that may potentially result in burns at the patient return electrode, particularly under procedural conditions in which the patient return electrode system is overloaded.

For more detail on this issue, readers are referred to the 1998 ECRI Hazard Report titled "Skin Burns Resulting from the Use of Electrolytic Distention/Irrigation Media during Electrosurgery with a Rollerablation Electrode" published in the journal Health Devices, Vol.27, No.6.

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Comweld Medical Products Multe-flow Medical Oxygen Piston Regulator

The TGA received an incident report from a medical practitioner involving separation of parts from a Comweld Medical Products Multe-flow Medical Oxygen Piston Regulator while a patient was under oxygen therapy during transport. The regulator was connected to a small oxygen cylinder and the person had one hand on the cylinder and one hand on the regulator.

The inlet connection of this regulator is held to the main body by means of a circlip that allows a swivelling action for easy connection and positioning of regulator attachments. It appears that the circlip and its holding groove became very worn from repeated tightening of the regulator inlet connection or positioning of the regulator by leveraging the regulator attachments while the regulator was pressurised. The connection yoke could no longer hold the inlet connection to the regulator under the combined load from carrying the cylinder through the regulator and previous overloading of the yoke.

Carrying an oxygen cylinder by hand, using the attached pressurised regulator as a handle, or rotating the regulator body through its attachments to position it or to tighten the inlet connection, are not recommended practices.

Comweld had redesigned the inlet connection of this regulator in March 2001 to provide additional attachment strength in case unexpected, excessive leverage loads were incorrectly applied through attached connections. The regulator involved in the reported incident was an early model without the additional protection. Multe-flow regulators with the latest design inlet yoke connection are identified by the addition of 3 grub screws on the yoke outer surface. Any regulators manufactured before March 2001 (without the grub screws) can be returned to Comweld Medical Products for an upgrade for a nominal fee.


Users of medical compressed gas cylinders should follow the recommendations of the Gas Suppliers whilst storing, using and transporting these cylinders. Such recommendations are contained in a pamphlet entitled "Safe Handling of Medical Gases" which is available for example from BOC Gases. The pamphlets include advice on having cylinders "in use" firmly secured to a suitable support or contained in a trolley or stand, and moving cylinders only when their cylinder valve is closed and the regulator is either removed or de-pressurised.

Inlet connections should be tightened by means of the yoke tightening screw by applying only enough torque to seal the connection leak-tight. Overtightening may damage the yoke connection seal, leading to leaks which may not be stopped by further tightening.

Rotation (swivelling) of the regulator body in order to position it should only be done when the regulator is de-pressurised and the yoke tightening screw is initially loosened.

It should be noted that the early-design regulators should give trouble-free service if used appropriately. Also cylinders fitted with the newer-design regulators will still need careful handling in accordance to these recommendations, and the gas supplier cylinder handling recommendations.

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Statistics report

Device incident reports 01/07/2001 to 31/12/2001

Number received: 308

Cause of problem1
Biocompatibility 17
Component failure 68
Contamination 9
Design 16
Diagnostic Inaccuracy 2
Electrical 18
Inadequate Instructions 12
Labelling 7
Maintenance 7
Manufacture 27
Material/Formulation Deficiency 47
Mechanical 10
Not Applicable- ADR 1
Not Device Related 38
Other 42
Packaging/Sterility 4
Quality Assurance 10
Unknown 39
Wear/Deterioration 12
Death 25
No Injury 177
Serious Injury 75
Temporary Injury 42
Source Category
Medical Administrator 12
Specialist 20
Coroner 17
Nurse 46
Blood Bank 33
Hospital Supply Service 47
Other 23
Patient/User 4
Sponsor 59
Overseas Advice 23
Biomed Engineer 22
Result of Investigation
Bulletin Article 3
Company Warning 4
Compliance Testing 13
No Further Action 92
Not Investigated2 132
Other 24
Problem Not Confirmed 13
Product Improvement 18
Recall/Hazard Alert 16
Refer to GMP 8
Safety Alert 15
User Education 20


  1. The problem causes are not mutually exclusive. For example, a material deficiency may have led to a mechanical malfunction or a biocompatibility problem.
  2. Every report received by IRIS receives a risk analysis by the Scheme Coordinator and is discussed by a panel of technical and clinical professionals. In the case of reports that are "Not Investigated" the panel has made a decision that further investigation of the particular event is not necessary at that time. However, these reports are logged into the database for future reference and the trend of reports is monitored. In making their decision, the panel considers whether any similar reports have been received previously.

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