New Design Standards for Molders of Medical Connectors

An industry-wide push to eliminate the possibility of misconnected medical tubing is fostering the development of a new generation of medical connectors. The tubes and catheters that carry oxygen, medication, nutrients, and fluids to hospital patients have been connected to delivery systems via universally designed, small-bore luer connectors. That standardization reportedly has occasionally led to misconnections and subsequent patient injury or death.

In response, an international group of clinicians, manufacturers, and regulators, including the FDA, worked with the International Organization of Standardization (ISO) and the Association for the Advancement of Medical Instrumentation (AAMI) to develop ISO 80369 standards for the redesign of small-bore (<8.5 mm I.D.) connectors. The goal, according to the Global Enteral Device Supplier Association (GEDSA), is to “make it difficult, if not impossible, for unrelated delivery systems to be connected.”

GEDSA launched its Stay Connected initiative to support the changeover, calling the new connectors ENFit to differentiate them from traditional luer connectors. Feeding tubes with the ENFit connector are projected to be available by midyear.

The new connector design standards will apply initially to liquids and gases in healthcare applications. Eventually they will dictate connector size and shape for breathing systems and driving gases, enteral, limb-cuff inflation, neuraxial, and intravascular-hypodermic applications. Once the standards are completed, luer connectors will only be used for intravascular and hypodermic applications. All other small-bore connector delivery systems will be changed to ensure they can’t be misconnected to luers.

In the past, use of flexible materials like PVC, TPE, and TPU in connectors could allow a healthcare worker to “force” the connectors together, creating the potential for error. The new design standard requires stiff materials (flexural modulus above 700 MPa).

As one example of what connector makers are doing, German injection molder and moldmaker A. Hopf GmbH recently issued newly designed enteral connectors utilizing Tritan copolyester from Eastman Chemical, Kingsport, Tenn., to proactively satisfy the ISO/DIS 2 80369-3 requirements (photo). Use of copolyester rather than PC also satisfies French legislation banning BPA in food-contact materials for children, passed in 2013. That ban expanded to cover all food-contact applications in January 2015.