1、STD-BSI PD CR L3825-ENGL 2000 Lb24bb9 0850580 bTL PUBLISHED DOCUMENT Luer connectors - A report to CEN CHeF from the CEN forum task group “Luer fittings” ICs 11.040.20 PD CR 13825:ZOOO NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITIED BY COPYRIGHT LAW STD-BSI PD CR L325-ENGL 2000 Lb24bb9 O50583
2、538 PD CR 13826:2000 been prepared under the direction of the Health and Environment Sedor Committee, was published under the authority of the Standards Committee and comes into effect on 16 June 2000 Amd. No. Q BSI W2 ISBN O 580 34983 7 National foreword Date Comments This Published Document reprod
3、uces verbath CR 13825:2000. The UK participation in its prepasation was entrusted to Technicai Committee CHE, Hypodermic equipment, which has the responsibility to: - aid enquirers to understand the te to a hypodermic syringe in order for the syringe or a connected device to achieve its intended pur
4、pose. 2) That Luer connectors should NOT be used: o with devices intended to be connected to the enteral or respiratory system; specifically, they should not be used for making connections to any catheter (other than a catheter intended to be placed in the vascular system) or to components or access
5、ories to breathing systems, and accessories or other devices connected to the respiratory system for the purpose of delivering gases; o with systems intended to deliver compressed air or other gases to medical devices e.g. driving gases; for connections within medical device systems which are used t
6、o control or monitor the operation of that system; with patient-connected drainage devices. Page 4 PD CR 13826:2000 That CEN, in conjunction with EO, develops standards for alternative connectors for enteral and respiratory applications, including the connection between an enteral feeding set and an
7、 enteral feed container. That the scope and titles of EN 20594-1 and EN 1707 be amended to replace the phrase “and certain other equipment” with one that reflects the restriction to devices connected to the vascular system. That CEN asks relevant Convenors to review the standards (published and unde
8、r development) for which they have responsibility which permit the use of Luer connectors, amending those in which the device does not fit the revised connector standard. 3. BACKGROUND In 1997 concern grew regarding the proliferation of devices fitted with Luer connectors and the direct consequence
9、of patient death or injury arising from the misconnection of particular devices, or the inappropriate delivery of enteral solutions, parenteral feeds or compressed gases. Specific concerns were raised by CEN TC 205 regarding the use of Luer connectors with enteral feeding tubes and from CEN TC 21 5
10、regarding gas sampling and gas delivery systems. Supported in principle by clinical and device experts together with a knowledge of actual and anecdotal incidents, these concerns were raised with CEN BTS 3 and the Commission through the Medical Devices Experts Group. In November 1997 the problem was
11、 aired at the final CEN BTS 3 Healthcare Forum and the newly created CHeF steering group set up a Forum Task Group (FTG) to debate the problem. Membership of the FTG was by invitation; CHeF ensured that there was appropriate representation drawn from users, device manufacturers, European Standards b
12、odies and European regulators. The FTG met on three occasions between January and October 1998. The FTG was asked to review the current evidence relating to real and potential problems arising from the misconnection of devices utilising Luer fittings, and to make recommendations regarding the applic
13、ation of Luer fittings to medical devices in order to reduce potential hazards arising from their misconnection. The remit of the FTG did not cover the design of the Luer connector itself; existing standards adequately specify constructional requirements. The security of the connectors is adequate f
14、or the intended purpose providing they have been correctly manufactured and are used appropriately. STD*BSI PD CR L3825-ENGL 2000 Lb24669 085058b OLT W Page 6 PD CR 13825:2000 4. PROBLEMS ARISING FROM THE USE OF LUER CONNECTORS. The increasing complexity of medical interventions, and the associated
15、medical devices, has led to a requirement for users to connect a multiplicity of external tubes to various types of diagnostic and therapeutic devices before use. Typically a patient in a coronary care unit will be connected to a range of devices incorporating Luer connectors. It has been estimated
16、that there are as many as 40 connectors on the devices used with a single patient. It is not therefore surprising that misconnections are made either inadvertently or due to confusion because of the large number of potential connections or because connector sequencing has been lost. However, whilst
17、there are many anecdotal reports of misconnections, published evidence of serious incidents is scarce. Many clinicians will openly admit that misconnections are commonplace but go unreported either because the mistake was rectified in time or because a serious hazard did not arise from the event. Di
18、scussions with other medical device regulators reveal that commonplace but potentially serious events are not reported because users consider them as normal events. Reports which have been published, or that could be otherwise substantiated include: * misconnections resulting in enteral feed being d
19、elivered parenterally (with fatal consequences) have been reported in a number of countries including France, Belgium7 and Canada . * fatalities have resulted from the direct delivery of oxygen intravenously: in the UK through the use of a male-male Luer adaptor , and recently in France due to inadv
20、ertent connection of an oxygen “bubble” tube a Luer connector lo. * enteral feed has been delivered into the inflation cuff of a tracheal tube resulting in total occlusion of the patients airway (the connector to the inflation cuff is a female Luer, as this is normally inflated by a syringe). transp
21、osition of the aspiration and actuator lines of a vitrectomy handpiece, resulting in a jet of gas entering the patients eye, has been reported from two hospitals in the USA12. All the lines are fitted with Luer connectors. In addition, a stopcock may also be fitted to permit connection with another
22、handpiece. * liquid was inadvertently delivered into the breathing system, fitted with a female Luer connector, resulting in decreased oxygen saturation of the patient13. A review of reports indicates that problems can arise from two distinct events: 1) the attachment of a delivery system (parentera
23、l fluid, enteral feed or gas) to an inappropriate device, or 2) the connection of two devices each of which is fitted with a Luer connector but are not intended to be connected in normal use. STD.BSI PD CR L3825-ENGL 2000 m Lb24669 Qll505 T5b m Page 6 PD CR 13825:2000 5. RISK ASSESSMENT Fundamentall
24、y, there are three main routes of delivery to the body: intravascular, enteral and respiratory. Some medical devices are intended to be connected to one of these routes depending upon the application or function of the device, via Luer connectors. Misconnections, which result in the delivery of a su
25、bstance inappropriately to the body, create risks to the patient. The table below shows a simple assessment of risk associated with the accidental cross-connection between these three systems. Delivery Route a Intravascular Enteral Respiratory 8 Application Parenteral + + - - Enteral Feed + + Respir
26、atory Gases + + - Gas Monitoring + I - Inflating Gas + + + CVS Monitoring - I - KEY: Intended connection, or little risk to patient foreseeable. Risk to patient, with fatal consequences if condition is allowed to persist. Immediate fatal risk to patient. + Some risk to patient. + + Table 1 . Simple
27、assessment of risk arising from misconnection between different delivery systems. Misconnections which result in the introduction of enteral products or gas into the vascular system are likely to result in death. Serious injury results from misconnections which permit the introduction of gas into th
28、e patients stomach or the introduction of a liquid into the breathing system, particularly if the error is not corrected. The result of inadvertent introduction of a sterile fluid into the patients stomach will largely depend on the nature and volume of the fluid. Whilst this event might not directl
29、y harm the patient it is a situation which shoyld bt! avoided. STD.BS1 PD CR L3825-ENGL 2000 Lb24hb9 0850588 992 m Page 7 PD CR 13825:2000 6. DISCUSSION 6.1 Human factors A paper by Allnutt5 reviews the role of human factors in accident areas such as aviation, nuclear power and marine transportation
30、. He makes the point that all human beings, without any exceptions whatsoever, make errors and that such errors are a completely normal and necessary part of human cognitive function. He goes on to say that whilst many accidents are put down to human error (which is synonymous with user error) the g
31、uilty party may be someone else, for example the trainer, the equipment designer, the equipment purchaser etc. Well-designed equipment can prevent or at least ameliorate the effects of an error, in his opinion. We must expect users to misconnect devices which are provided with compatible connectors,
32、 and recognise that the potential for misconnection will rise as the number of devices with similar connectors increases. 6.2 Safety under single fault conditions Medical devices have for very many years followed the established principle of “safety under single fault conditions”. Simply stated this
33、 means that a single fault should not result in a hazard. This principle is embodied in numerous medical device standards. Extending this principle to the application of Luer connectors is a logical step, .e. that misconnection should not result in a patient hazard. 6.3 Inherent safe design Misconne
34、ction of devices with Luer connectors is a frequent event. The widespread use of Luer connectors on a multitude of devices can therefore result in connections which have serious, or even fatal, consequences for the patient. Fundamentally, the problem results from the application of a single connecto
35、r design to a number of incompatible applications. 6.4 The Medical Device Directive 93/42/EEC14. The MDD addresses this type of problem in Essential Requirements 1.2. (solutions adopted . . . . . .for the design and construction of devices must conform to safety principles, taking into account the g
36、enerally acknowledged state of the art, In seeking the most appropriate solutions, the manufacturer must apply the following principles in the following order: - eliminate or reduce risk as far as possible (inherently safe design and construction) etc . . . . . . .) and 9.1 (If the device is intende
37、d for use in combination with other devices or equipment, the whole combination, including the connector system must be safe etc. . . . , . . . .) Providing alternative connectors for the applications identified earlier could significantly reduce the problem of misconnection. STD-BSI PD CR L3825-ENG
38、L 2000 m Lb2qbb9 0850589 829 m Page 8 PD CR 13825:2000 7. prEN 13014: CONNECTIONS FOR GAS SAMPLING TUBES TO ANAESTHETIC AND RESPIRATORY EQUIPMENT. At the request of the CEN Consultant the FTG spent some time considering the suitability of this prEN, which permits the use of Luer connectors at gas sa
39、mpling and return ports and for the connecting tubes. A number of objections were made: * Luer connectors are permitted for a purpose other than the intended application. * In order to maintain sequencing within the gas sampling system the connecting tubes terminate either in male connectors (gas sa
40、mpling tube) or in female connectors (gas return tube). This is potentially dangerous in a clinical environment as it provides a means of overcoming connector sequencing which has been introduced into other devices to reduce the possibility of misconnection. * The provision of Luer connectors in bre
41、athing system components increases the risk of inadvertent connection to that system. Some misconnections could be life- threatening for the patient. ( See Table1 .) In summary prEN 1301 4 is not in accord with the FTGs major recommendations. It is seen by some that this prEN is a significant improv
42、ement on the current situation and that it will will serve as a useful interim approach. A long-term solution involves developing an alternative connector for respiratory applications. Page 9 PD CR 13825:2000 8. CONCLUSIONS The FTG recognised that connector systems could not be designed so as to ove
43、rcome all chances of misconnection or eliminate deliberate misuse. However a number of initiatives could be taken forward which would improve the current situation and would lead to a greater degree of patient safety. Luer connectors are well established in many applications and the FTG recognise th
44、at improvements to the current situation will only be achieved through a long-term commitment involving industry, users, standardisation organisations and medical device regulatory authorities. It was also recognised that this is a world-wide problem and, ideally, international involvement is necess
45、ary. The problems of misconnection may result in the delivery of substances to the body inappropriately, which may have serious consequences for the patient. During discussions the FTG considered a number of means that could be used to reduce the possibility of misconnection. In particular colour co
46、ding of connectors was considered. This approach was thought to be impractical because of the large number of colours that would be needed. Furthermore there would need to be extensive co-operation within industry to ensure that the same colours were used throughout. Also colouring connectors may in
47、crease confusion with established colour coding systems for medical devices already in use. From a user point of view, some have difficulty in differentiating colours (colour blindness) and procedures performed in subdued lighting identification could be a problem even for users with normal vision.
48、A second option of restricting th.- tise of Luer connectors to transfer or delivery of liquids was also considered. This approach has a possible drawback since syringes are often used, for example for aspiration or the inflation of the cuff of a tracheal tube. Furthermore, fatalities resulting from
49、the administration of enteral feeds intravenously have been reported despite the availability of enteral feeding tubes with reverse sequence Luer connectors. The availability of adaptors and three-way taps means that sequencing can be easily overcome in the clinical environment. For this reason the FTG recommended that an alternative, non-Luer connector should be developed for enteral applications. Standardising a specific connection between the enteral feeding set and the enteral feed container would further enhance safety. The FTG agre
