Enteral Syringe Safety: Unintended consequences of ENFit™
The Good, the Bad, and the ENFit
Misconnections between small-bore medical tubing have caused several cases of morbidity and mortality for patients receiving enteral medications and feeding. The Global Enteral Device Supplier Association (GEDSA) was formed to drive the design and adoption of international standards for medical device tubing connectors with the goal of increasing patient safety. Working with the International Standards Organization (ISO), the standard ISO-80369 was developed to specify the dimensions for six different types of small-bore tubing: airway, enteral, urinary (on hold), BP cuffs, neuraxial, and intravenous. Improving safety with better design is a great way to eliminate the risk of tubing misconnections, and GEDSA should be commended for paving the way towards enteral safety. Unfortunately, several unintended consequences may render the gains in safety moot.
ISO-80369-3 is the standard that deals with enteral connections/connectors. The standard specifies the exact standards for shape, size, physical properties, functional performance, and material characteristics. The standard permits both a male and female orientation for the design. The new ENFit connection reverses the traditional orientation of the tubing connection, where the male end is the “giving” end, and the female end is the “receiving” end. GEDSA insisted on incorporating the reverse orientation to create a “physical cue unique to enteral devices” but without any data to support the superiority of one design over the other http://stayconnected.org/wp-content/uploads/2019/03/GEDSA-White-Paper-2019.pdf . Why is this important?
The ENFit syringes have a reverse orientation. Changing the design will alter the dead space found in the syringe tip. The syringe tip now goes around the tube, instead of inside the tube. The syringe tip changes can have a profound impact on both under and over-dosing depending if the syringe is used for enteral versus oral administration, the method of syringe filling, and the type of medication (liquid, ground tablets, etc.) used. Additional ramifications of the ENFit design will be discussed in subsequent blog posts.
Concerns were raised regarding dose accuracy of the ENFit enteral syringes, especially when used for low volumes of medications. GEDSA claims to have gained consensus by experts from ISMP, ASHP, ASPEN, and others that a +/- 10% dose variance was acceptable and proceeded to design a “low dose tip” feature to counter the design flaws with the ENFit connector. Readers, please note, clinicians have come to expect a +/- 5% dose variance from syringes compliant with ISO-7886, and the decision to accept the greater variance was not based on a valid consensus process.
GEDSA published a “research poster” to demonstrate the improved performance of the “low dose tip” feature http://stayconnected.org/wp-content/uploads/2016/10/GEDSA-ENFit-LDT-Research-Poster.pdf . The syringe testing study was not peer reviewed, and secondary analyses performed by third-party labs could not reproduce the same results. Recently, O’Mara et al. at Shands conducted in vitro testing comparing a legacy enteral syringe to the ENFit syringe and the ENFit syringe with the “low dose tip” feature. The study raises clinical concerns of dose inaccuracy with the LDT syringes, particularly with 0.5 and 1-mL sizes. The use of recommended adapters significantly increases the opportunity for inaccurate dosing.
A growing number of voices are now speaking up about the safety issues associated with the ENFit design and specifically the ENFit syringes, including the National Coalition for Infant Health, the Institute for Patient Access, the French Society of Neonatology, and the Canadian Standards Agency Working Group. The members of GEDSA have been silent about the research findings associated with the ENFit syringes.
A new ISO standard specifically for enteral systems will be published in February 2020. Pharmacists should be aware that the ISO -20695 will not include the ENFit syringes with the “low dose tip” feature. Essentially, the working group has determined that:
- The Low Dose Tip syringe (LDT) is recognized for not reliably increasing dose accuracy.
- The LDT has been removed from the mandatory requirements and is now included as information only in an appendix.
- The LDT is now called enteral alternative syringe tip because it can’t ensure accuracy of low medication doses.
What should you do?
Consider the medication safety implications. The opportunity to deliver an inaccurate dose far exceeds the number of opportunities for an enteral tubing misconnection. The impact of inaccurate dosing on patient response to medications and/or change in condition is difficult to tease out, making this type of error difficult to detect and dangerous. Vendor changes such as syringe color coding, offset tips, and design changes to the proximal and distal enteral system tubing connections have reduced the risks of misconnection harm to patients. The ISMP reports that wrong route medication errors persist even in hospitals that are using ENFit syringes – as the human element cannot be eliminated.
Speak up in the appropriate forums at your hospital. ENFit manufacturers are not acknowledging that the ENFit syringes are not safe for medication administration. Consider that the ENFit manufacturers only have FDA 510(k) clearance to market the syringes for use as a dispenser, a measuring device and a fluid transfer device via oral or enteral route – NOT medication administration. Consider the heartbreak, legal implications, and reputational loss when a neonate suffers serious morbidity or mortality associated with medication errors caused by a syringe with known dose inaccuracy. There is no regulatory requirement to adopt ENFit. There is a requirement to use a safe enteral system. It may be in your patient’s best interest not to adopt ENFit at this time.