Replacing Luer connectors: still work in progress

At the time of writing, all NHS trusts and independent healthcare institutions in England and Wales will be required to take action to use spinal needles with non-Luer connectors by 1 April 2011 [1]. This important target follows repeated calls to design a solution to make it physically impossible to connect medications intended for intravenous administration to spinal needles [2-5]. However, < 6 months from the implementation date, new devices are only just beginning to appear on the market and there is only one clinical study of a connector prototype in the peer-reviewed literature [6]. In this issue of Anaesthesia, Cook et al. describe the results of bench tests undertaken by experienced clinicians that demonstrate that two new connectors required further modification (n.b. both have been modified since the study) [7]. Why has it been so hard to find a simple engineering solution to a problem that was first described more than 40 years ago [8]? German medical instrument maker Hermann Wülfing Luer designed the Luer connector in 1896 and suggested that the simple 6% taper for glass bottle stoppers be used to provide a secure connector for intravenous devices. A threaded collar was described by Fairleigh Dickenson in 1925, and by the 1960s, the Luer-Slip® and Luer-Lok® connectors were the most common in clinical use [9]. Unfortunately, the success of the Luer connectors in healthcare has also been a major failure as they risk misconnection between a multiplicity of different devices and provide no protection against wrong-route drug errors [10]. The first death due to accidental intrathecal vincristine was in 1968 and since then, there have been at least 58 deaths worldwide, probably with many more unreported [11]. Enteral feeds, epidural local anaesthetic infusions, capnography tubing, non-invasive blood pressure devices and oxygen tubing have all been connected to intravenous devices, resulting in numerous fatalities. In the words of a recent Sentinal Event Alert from the Joint Commission, ‘if it can be done it will be done’ [12]. In the UK, the most recent case of intrathecal vincristine was in 2001 and resulted in the death of Wayne Jowett, a teenager who was in remission from leukaemia and was to receive his last treatment [2, 3]. This tragic accident occurred the year after the publication of the Department of Health’s report ‘An Organisation With a Memory’, which highlighted the importance of learning from rare, but serious, adverse events in healthcare such as vincristine medication errors [13]. The external accident inquiry into the death of Wayne Jowett carefully documented the latent conditions and active failures that enabled the intravenous chemotherapy to be transferred from the pharmacy to the room where the intrathecal chemotherapy was to be given. The universal Luer connector enabled the vincristine syringe to be attached to the spinal needle, thus removing the final safeguard for the patient [2]. Awareness of human factors and system errors will never provide fail-safe protection and a physical solution to prevent accidental misconnections would seem essential. Since then, national guidance on the administration of chemotherapy has been updated, and the UK has followed other countries in stipulating that intravenous minibags should be used for all vinca alkaloids, although in the UK, vinca alkaloids are still administered by syringe for children under 10 years as there are concerns about extravasation injury [14]. Intrathecal injection from a minibag would be exceptionally unlikely due to the formulation and volume contained. However, a non-interchangeable system to ensure that drugs intended for the intravenous route cannot be given intrathecally still remains appropriate. In anaesthetic practice, wrong-route errors are much more common when epidural drugs are given intravenously or vice versa. A recent tragedy in Australia, in which chlorhexidine cleaning solution was drawn into an epidural loss-of-resistance syringe reminds us that a new connector cannot prevent the wrong drug from being given [15]. There were 20 wrong-route epidural injections reported to the National Patient Safety Agency (NPSA) between 1 January 2005 and 31 May 2006, including six incidents in which epidural medications were given via the intravenous route [16]. In recent years, there have been four deaths reported in the UK due to intravenous bupivacaine, one occurring after the NPSA issued a Patient Safety Alert concerning wrong-route epidural infusions [17, 18]. Again, an engineering solution would seem essential, and this is the subject of ‘Part B’ of the NPSA Safety Alert to replace all epidural, spinal and regional anaesthesia connectors with non-Luer connectors by April 2013 [18]. The best example of an engineering solution to solve risk in anaesthesia is the hypoxic guard developed to prevent the administration of hypoxic gas mixtures to patients. This practical solution has undoubtedly saved many lives. There have been efforts to encourage development of new non-Luer connectors for spinal needles, and a number of prototypes have been put forward for testing. The Department of Health proposed that European manufacturers should design a replacement for the Luer connector in 2002 [4] and commissioned research through the Department of Health Patient Safety Research programme [19]. This included a hazard analysis, evaluation of prototypes in simulators, and pilot evaluations of new devices in clinical practice. In 2004, the NPSA conducted a risk assessment that concluded that all spinal injections should be undertaken using needles with non-Luer connectors. The main threat envisaged was logistical, in obtaining and distributing sufficient supplies of new equipment when a changeover was made [20]. The Department of Health sponsored the Bath Institute of Medical Engineering and the University of Leeds Institute of Psychological Sciences to undertake a series of bench tests using a spinal (and epidural) simulator for anaesthetists and non-anaesthetists involved in chemotherapy administration to assess connector prototypes. In 2006, two prototypes were submitted for testing; one did not proceed for further assessment, and another was modified by the manufacturer following comments from clinicians [21, 22]. In this issue of the Journal, Cook et al. describe their comparison of two new connectors with standard Luer connectors for spinal and epidural needles [7]. Clinicians from one hospital participated (40 anaesthetists, 19 physicians), all said to perform lumbar punctures or epidurals regularly. The results indicate that at the very least, there will be a learning curve for using needles with the new connectors, with users feeling that they did not perform as well as conventional equipment. Anaesthetists preferred different manufacturers’ connectors for spinals compared with epidurals. Interconnection with Luer connectors was possible with both of the new connectors, and there were also concerns about leakage and the force needed to use the connectors. There is only one report of clinical product evaluation, in 362 patients undergoing spinal anaesthesia or intrathecal chemotherapy using needles with the Neurax® connector [6]. Although clinicians supported the principle of non-interchangeable connectors, they encountered similar problems of leakage and difficulty in connecting the syringe and needle as in Cook et al.’s study. Pharmacy technicians also found the connectors more difficult to use when preparing chemotherapy drugs. The manufacturers can be congratulated for working closely with research teams to refine their product design. However, until further clinical evaluation is available, the findings would seem to imply that the search for a new neuraxial connector is still a ‘work in progress’. All equipment used in the NHS is required to be CE (Conformité Européenne) marked, which is the manufacturers’ declaration that the product complies with the relevant European legislation, which in practice includes European technical specifications. Standards for medical equipment are voluntary and are led by manufacturers with input from other stakeholders. They are developed at national (British Standards Institute, BSI), European (European Committee for Standardization, CEN) and International (International Standards Organisation, ISO) levels. Once the need for a standard is agreed, a series of meetings is held to obtain a consensus view from manufacturers, users, testing laboratories, governments, engineering professions and research organisations [23]. The European Medical Device Vigilance system received reports of deaths due to Luer misconnections in the 1990s and a Task Group of experts reported to CEN in 2000, recommending that Luer connectors should only be used for vascular devices, but that all other connectors should be replaced [24]. The British Standards Institute and CEN published the standard for general requirements for small-bore connectors in 2008 [25], and the ISO standard is still only at approval stage [26]. There are currently two international standards for the Luer connector: ISO 594/1 describes the Luer-Slip; and ISO 594/2 describes the Luer-Lok [27, 28]. There is currently no ISO standard governing the use of non-Luer connectors. It would appear that the process for development of a new international standard for non-Luer connectors has not been effective in responding to clinical concerns. In 2009, the Health Select Committee expressed frustration about the delayed introduction of a non-Luer spinal needle [29]. In the words of the Committee: ‘It is unacceptable that the NHS does not have a mechanism to ensure that changes such as this, which impact seriously on patient safety, occur in a timely fashion’. In response, the NPSA convened an External Reference Group on Safer Neuraxial Devices, with anaesthetic representation and chaired by Professor Brian Toft, to oversee the introduction of non-Luer connectors. The NPSA had previously released a number of Safety Alerts relating to Luer connectors, in particular one concerning oral medication and enteral feeding [30]. This required the NHS to purchase enteral systems with non-Luer connectors within 6 months, a target relatively easy to achieve as the manufacturers had had a safe solution on the shelf for a number of years. Purple reverse-Luer connectors for nasogastric tubes are now the norm in the NHS. The Safety Alert issued by the NPSA in November 2009, after consultation with the External Reference Group, was intended to drive the change to non-Luer connectors for spinal needles in the NHS in the same way as the enteral systems alert [1, 30]. A recent Newsletter from the NPSA indicated that 10 manufacturers should be bringing devices to the market in the near future based on the two new connectors described in the Cook paper. The NPSA Newsletter has suggested that trusts should request samples for examination by hospital clinicians in order to obtain their feedback on which of the devices they are willing to use [31]. If suitable equipment is unavailable, this should be entered into the trust’s Risk Register (a document that all NHS trusts are required to keep, detailing risks in the organisation, who is responsible for leading an action plan, and a completion date for the change required [32]). Although unintended, there is likely to be pressure on clinicians to use new equipment to avoid wrong-route errors, given the Department of Health’s guidance on intrathecal chemotherapy and introduction of the Corporate Manslaughter and Homicide Act 2007 [14, 33]. The Alert will need to be implemented carefully to avoid exposing patients to equipment that has not completed user testing, and specific training with the new devices will be required [6]. The concerns of the profession regarding the timetable for introduction of new products without clinical evaluation have been the subject of a statement by the Association of Anaesthetists of Great Britain & Ireland [34], the Royal College of Anaesthetists [35], the Obstetric Anaesthetists’ Association [36] and the Association of Paediatric Anaesthetists of Great Britain and Ireland (personal communication). Around 315 000 spinal anaesthetics are performed annually in the UK [37], and when introducing new equipment to improve patient safety we should be mindful of Liam Donaldson’s comment in his report of 2002: ‘We need to be certain that any potential new design solution is rigorously tested and, crucially, that by introducing new equipment to prevent one specific type of error, we do not, in turn, introduce new unforeseen risks to patients’ [4]. What can we learn from this whole process, and in particular, why has it taken so long to come up with an engineering solution to a problem that has resulted in deaths during routine clinical care? The Department of Health’s research funding in 2002 was intended to encourage development of new products, but this appears to have had little impact. The Chief Medical Officer introduced NHS Innovation Hubs in 2004 to translate the ideas of frontline clinical staff into commercial solutions to improve patient care [38]. However, medical device manufacturers need to identify a market before investing in developing new, high-volume low-cost products even when patients’ safety is at stake [39]. The NPSA was established in 2003 to promote patient safety; this year, plans were announced to transfer this function to the newly formed NHS National Commissioning Board and it is hoped that the focus on neuraxial connectors will not be lost [13, 40]. When a device fails in the transport or aviation industry, products may be withdrawn and there is a concerted effort to introduce a technical fix to ensure client safety and brand protection. In healthcare, we do not have this same response, but seem to focus on individual doctors and expect them to try harder even though we know that this is not an effective solution [13]. The NHS in England is a £100 billion industry and has a crucial role in promoting the development of safer devices in healthcare [41]. If the NHS is serious about developing a safety purchasing policy, then investment is required. The cost of developing suitable non-Luer connectors would be considerably less than the medicolegal consequences of the next wrong-route injection. When a direction is given by the Chief Medical Officer that equipment should be changed in the NHS, a determined funded effort should take place to describe the solution. If this had happened, we could have been there years ago. All authors are members of the AAGBI Council; IAW also chairs the AAGBI Standards Committee and IHW is AAGBI President. The AAGBI was represented on the NPSA's External Reference Group but none of the authors were members of this group. The above views represent the authors’ personal views. doi:10.1111/j.1365-2044.2010.06536.x