Leur Connectors for Medical Applications

Standards, Problems And Important Issues

(Abstracted from an article by Dr. Trudy Phelps, Standards Director, Association Of British Healthcare Industries, published in The Journal Of Abhi, Association Of British Healthcare Industries, www.abhi.org.uk)

The Luer is a conical connector that was first patented in 1898 and is based on 6% taper. It can be made from plastic, glass or metal. It is small, neat and safe, especially when the variant locking device is used. The original purpose of the Leur fitting was to connect a hypodermic needle to a syringe.

The newer design for Leur connectors is required due to its widespread use into a wide range of medical devices and equipment used in modern healthcare, including syringes, needles, sample lines, liquid and gas delivery systems and monitoring devices. The wide-spread use of the Leur connectors permits misconnection between various devices and delivery systems. Misconnection may lead to death or serious injury. Reports of fatalities and serious injuries have resulted from :

• Enteral feed delivered intravenously,

• Gas lines connected to IV lines,

• Gas lines connected to tracheal tube pilot ballons,

• Eteral feed connected to a pilot balloon,

• Non-invasive blood pressure cuffs connected to IV lines,

• Intravenous drugs administered intrathecally (into the spine).

The misconnection was noted by FDA and it is given at the end of this article.

Need for Standardization

Because of Widespread use and acceptability of Luer connectors for medical applications, it was standardized in order to ensure compatibility between connectors from different manufacturers. Standards were developed for the connector, which have been published in Europe and internationally. The standards, however, allow Luer connectors to be used not only for syringes, needles and intravenous devices (as was the original intent) but also for certain other devices. The proliferation of use of the Luer connector for the ‘other devices’ has led to the problem.

The industry has already come across such problems. Some of the incidents have been reported to national bodies, some are reported in the medical literature and the press while others are anecdotal.

Many are probably not reported as misconnections but rather attributed to human error.

The most publicized cases have involved the intravenous administration of enteral feeding formulas, and the intrahecal administration of an anticancer drug that should only be administered intravenously.

Independent investigations into these fatalities have identified a number of measures to prevent recurrence. Although the connectors alone were not the only factor leading to misconnection, design changes to the connectors should be considered, together with risk benefit and health economic analysis.

Steps Taken For Highlighting the Problem :

The European standardization body CEN first set up a Forum Task Group several years ago over Luer misconnections throughout Europe and also published a report confirming that there is a problem arising from the application of a single connector design to a large number of incompatible applications. The group recommended in CEN report that use of the Luer connector should be restricted to devices intended to be connected to the vascular system or hypodermic syringes, and in addition, that new designs of small-bore connectors should be developed for the non-intravascular applications. A CEN BT Task Force, CEN/BT/TF123, was set up to take forward these recommendations.

A comprehensive risk analysis of the current situation has been produced and has resulted in agreement that alternatives to Luer connectors should be developed for enteral respiratory, neuraxial and circumferential cuff inflation. A Part 1 standard detailing general requirements for small bore connectors has been drafted and was recently circulated as prEN 15546-1 for public comment. To make contact through the CEN/BT Task Force 123 the website is  http://ecom.afnor.org/livelink-en/livelink.exe

Preventing Fatal Tubing Misconnections

Reference :
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/psn/transcript. cfm?show=31

Here’s a new example of what can happen when patient tubing is misconnected.

In a previous program, we cited a case where the tubing from a portable blood pressure monitoring device was mistakenly connected to the patient’s IV line, and the patient died from an air embolism. In another case, an air supply hose from a pneumatic compression device was inadvertently hooked up to a needleless IV tubing port. This patient, too, could have died, if the mistake hadn’t been caught in time.

In a recent Safety Alert, the Institute for Safe Medication Practices reported on another case of tubing misconnection, this time involving a hospitalized child being treated for asthma. The tubing that connected an oxygen wall outlet to the child’s nebulizer became disconnected. A staff member later reattached this oxygen tubing to the Baxter Clearlink valve on the patient’s IV set, and the child died. Baxter has issued a safety alert to directors of nursing on this type of tubing misconnection hazard.

ISMP notes that oxygen tubing generally doesn’t have a Luer connector, but they point out that it’s still possible to make a connection between the tube and a Clearlink valve if you use excessive force. Although this kind of connection might not hold for very long, it only takes seconds for an air embolism to occur and kill the patient if you connect an oxygen or air tube to an IV port.

ISMP says that staff training is vital in preventing these kinds of accidents. They suggest that whenever tubing is connected or reconnected to a patient, staff should be required to completely trace it from the patient to the point of origin. They also note that if IV lines were labeled, this could help alert staff if they were about to access that line accidentally.

ISMP points out that it’s possible for anyone, even a trained professional, to misconnect patient lines, but that untrained people, like ancillary staff, students and transport personnel, are more likely to commit errors. And so ISMP recommends that these people not be allowed to connect and disconnect patient tubing.

ISMP notes that in the rush of patient care, sometimes a student or a transport worker or a lab technician will be asked to connect or disconnect a tube. ISMP suggests that these people be taught how to refuse if someone asks them to connect or disconnect medical tubing.

(http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/psn/transcript.cfm?show=31)