A clinical evaluation of four non‐Luer spinal needle and syringe systems

Abstract

We performed an evaluation of non-Luer spinal devices supplied by four manufacturers or suppliers: Polymedic; Pajunk; Sarstedt; and Smiths. For each supplier, 100 evaluations were performed using a 25-G 90-mm spinal needle, 3-ml syringe, 5-ml syringe and filter needle; for comparison, 100 evaluations were performed with our standard Luer equipment. The non-Luer devices were associated with more qualitative problems compared with the Luer devices, for example, poor feel of dural puncture (9-32% vs 10%, respectively), poor observation of cerebrospinal fluid in the hub (3-27% vs 0%), and connection problem of the syringe to the spinal needle (7-33% vs 0%). There was also more frequent failure to achieve the spinal injection due to equipment-related causes (4-7% vs 0%, respectively). . Between 21% and 75% of non-Luer evaluations were rated with satisfaction worse than the usual Luer needle compared with 0-10% rated better, depending on the needle type. Between 22% and 76% of non-Luer evaluations were rated with satisfaction worse than the usual Luer equipment compared with 0-14% rated better. Specific concerns included poor feel of tissue planes and observation of cerebrospinal fluid (Polymedic), difficulty with connection of the syringe to the spinal needle and trocar removal (Pajunk), poor feel of tissue planes and needle flexibility (Sarstedt) and difficulty with connection of the syringe to the spinal needle (Smiths). We could not demonstrate a short-term learning curve for the new devices. Decisions on purchasing and implementation of the new non-Luer equipment will have to acknowledge that clinicians may have greater technical problems and reduced satisfaction compared with the current equipment.

An evaluation of non‐Luer safety connectors for neuraxial procedures

“…Although the amount of rotation of the syringe grooves over the needle guides are similar to the distance turned when securing a slip syringe by frictional forces, and are less than in a full locking system, we feel that this syringe is somewhat of a hybrid design. Kinsella et al reported a small series of slip syringes with huge leaks (37%), far higher than seen in any of our assessments [4]. This is probably explained by differences in familiarity with locking and slip systems between the two hospitals [4].…”

“…The hub of the Neurax needle was coloured and this may explain the difficulty some observers had in seeing CSF clearly when using this system. Kinsella et al studied locking syringes and quoted leak rates of 0-8% in non-Luer products and 0% with Luer [4]. In our assessment of slip syringes, we found that the Smiths' syringe did not leak at all, the Suretybased slip systems leaked less often than the quoted figures for Kinsella et al's locking syringes and that Neurax and BD leaked with the greatest frequency (9% and 13%, respectively).…”

“…The systems currently available are regarded as compliant with the NPSA alert (David Cousins, NPSA, personal communication). Kinsella et al published an assessment of four of these NPSAcompliant spinal systems, with two different connectors, and compared them with their current Luer system [4]. They found that the majority of users favoured the existing Luer systems.…”

Clinical evaluation of non‐Luer needle and syringe systems

“…In response to our article [1], Professor Toft and Dr Cousins outline part of the ideal method of assessment for new equipment, including a like-forlike comparison of the products from all suppliers and the elimination of bias. In an ideal world there would be extensive bench and manikin testing of the products in advance of use in humans.…”

Innovations, inventions and Dr Archie Brain

“…Testing the new, non-Luer lock spinal needles sparked controversy as there were no firm guidelines relating to the evaluation of such equipment and trialling on humans presented ethical dilemmas with the inherent potential for more harm than good [12]. While the equipment has all attained a CE mark, there is no substantial proof of either efficacy or safety, although there have been attempts to assess these clinically [13]. This has proved frustrating both to the medical equipment industry, which has invested considerable capital in this new venture, and to its potential users.…”