ENFit Enteral Devices Are On Their Way...Important Safety Considerations For Hospitals
In our August 14, 2014 newsletter, we alerted health systems to upcoming changes in enteral feeding device connectors. An industry group, The Global Enteral Device Supplier Association (GEDSA), is coordinating this effort, and GEDSA member companies are introducing the new devices referred to as ENFit. The ENFit devices will not be compatible with a Luer connection or any other type of small bore medical connector, thus preventing misadministration of an enteral feeding or medication by the wrong route. Unlike current parenteral and oral syringes with male syringe tips that fit into female connectors, the new ENFit devices are just the opposite. They have a female tip on the syringe that will fit around a male connector on feeding tubes (Figure 1).
We previously urged health systems to plan for the enteral connector design changes, but that has been difficult because the actual devices have not been available. In general terms, during the first quarter of 2015, we were anticipating availability of enteral administration sets with a new female ENFit connector and a limited-use ENFit Transition Connector to facilitate compatibility between the new ENFit system and the existing port. The ENFit connector system also requires the use of a new enteral-specific syringe that can be used for medication administration, flushing, and feeding. Distribution of the new ENFit syringes is supposed to begin in the current quarter. Any oral syringe currently in use (and any Luer-tipped syringe) will not work with the ENFit connector system. ENFit feeding tubes will begin distribution in the third quarter according to the published GEDSA timelines on stayconnected.org.
In our August 14, 2014 newsletter, we identified several unresolved process dilemmas that this changeover would trigger. Fortunately, these issues have been addressed, and we are happy to report that vendors have designed bottle adapters (Figure 2) and straws (Figure 2a), and syringe caps (Figure 3) to use with the ENFit syringes. However, ISMP has identified further safety issues for hospitals to consider as the connectors are introduced. When we recently received samples of the new devices and conducted simulations, we verified some measurement and administration issues reported to us.
Importantly, some patients could be at risk of dosing errors unless these considerations are understood and proactively addressed. Based on our simulations, here’s how we envision using the ENFit syringes, feeding tubes, adapters, and syringe caps. We have highlighted in italics the processes in the sections below that may present particular safety considerations.
Administering Liquid Medications Via An Enteral Feeding Tube
ENFit syringe to ENFit connection. If a dose of liquid medication must be administered via a feeding tube with the new enteral connector, an ENFit syringe must be used. In a recent guidance document, FDA suggested the syringes should be marked “Feeding/Medication Only.” An oral syringe will no longer connect to the feeding tube.
Measuring an enteral medication dose in pharmacy. An ENFit bottle adapter (Figure 2) should be affixed to the bulk bottle of liquid medication, and the correct dose should be withdrawn from the bottle using an ENFit syringe. If medicine must be withdrawn from a unit dose cup, an ENFit straw (Figure 2a) is available. It is important to note that dose measurement with an ENFit syringe is from the base of the syringe tip (where the gradation marks begin) to the correct gradation mark on the syringe (Figure 4). In this regard, no changes were made to gradient markings or how to measure a dose when compared to an oral syringe. A cap meant for an ENFit syringe should be securely placed on the filled ENFit syringe prior to transport (Figure 3).
Measuring an enteral medication dose in patient care units. While ISMP strongly recommends that liquid medications for patients with feeding tubes be prepared and dispensed in exact doses by the pharmacy, there may be times when healthcare professionals in patient care units must use an ENFit syringe to draw liquid medication from a unit dose liquid cup. When that happens, dead space in the tip of the ENFit syringe must be considered if an ENFit straw isn’t used. This dead space measures from 0.15 to 0.2 mL, and while this may not seem like much, it can be significant for certain drug doses, particularly in pediatric and neonatal populations.
Because of the dead space, when a practitioner uses the ENFit syringe and begins to draw up a medication directly from a unit dose liquid cup, there will be a small bubble of about 0.15 mL to 0.2 mL of air (Figure 5) that moves into the syringe first. To measure doses exactly, nurses must remove the air bubble and attempt to accurately measure the dose without allowing fluid to remain in the syringe tip, thus filling the dead space. Flicking the syringe to remove the air bubble may lead to some minor spillage as the medication sprays out of the wide female connector. Thus, as nurses first become familiar with the new syringes, there may be several attempts to withdraw the correct amount of medication from the cup into the ENFit syringe, each time requiring removal of an air bubble. The process can be messy and tedious, and can lead to incorrect dosing if the bubble isn’t removed.
For these enteral doses, one way to minimize the bubble and measure an accurate dose from a cup would be for nurses to use the ENFit straw attached to the ENFit syringe (Figure 2). This allows the nurse to minimize the dead space and promote easier dose measurement. Of course, this means hospitals must supply ENFit straws in patient care areas and educate nurses about the need to use them and how to use them.
Again, doses meant for a feeding tube are measured only using the syringe scale, and should not include a syringe tip full of medication, which can be avoided by using the bottle adapter (for enteral doses prepared in the pharmacy) or straw device on nursing units. With doses given via a tube, the dead space in the syringe should always be cleared of fluid during measurement of the dose and should also be clear of fluid when attaching the syringe to an ENFit connection on the feeding tube. If there is an accumulation of medication in the syringe tip when measuring a feeding tube dose from a medication cup (Figure 6), some of that may leak out when connected to the feeding tube or be injected via the tube, which may constitute a small amount of excess medicine reaching the patient. The volumes appear to vary depending on liquid viscosity, volume of fluid in the dead space, and force of injection caused by the syringe plunger when connected via the ENFit connector to the feeding tube.
As already mentioned, measuring a dose for administration via an ENFit feeding tube is only accurate if there is no medication in the dead space both before and after administration. This is a fundamental change in the way that nurses must measure medication doses for feeding tubes while using unit-dose cups since a straw must be used in the process. The added complexity has the potential to contribute to dosage error when very small amounts of liquid are needed for a dose, such as for infants.
ENFit syringe product vendors are aware of the issue of bubble formation and dead space when preparing doses directly from a cup of liquid and they are prepared to introduce solutions that may mitigate this concern. ISMP has not received anything to test and cannot comment on the safety or accuracy of what may be forthcoming.
Administering the medication. Once procedures have been followed to verify placement and/or flushing of the feeding tube, the ENFit syringe’s female connector should be attached to the compatible male connector on the feeding tube, and the medication should be administered (Figure 6).
Administering Liquid Medications by Mouth
Measuring and administering an oral dose of medication. For now, it would be safest to use an oral syringe to measure the dose and administer the medication by mouth, using the same techniques and devices currently in place.
Using ENFit syringes as the sole device. Even with excellent communication between nursing units and the pharmacy, it may be impossible for pharmacy to always know which patients can swallow and can use an oral syringe, and which have a feeding tube and will need an ENFit syringe. For patients with feeding tubes, medication orders should specify “via tube.” But even so, some patients may later have their tubes removed before pharmacy is notified, while others with feeding tubes can still swallow liquid medications orally. For simplicity, some hospitals have told us that they hope to be able to use ENFit syringes for both feeding tube administration as well as oral administration by mouth, thus eliminating the need for a second type of syringe without a Luer tip. But going with only ENFit syringes alone poses safety considerations, particularly for doses in small volumes, less than 2 mL, as described below.
Administering an oral dose via ENFit syringe. When a medication intended for oral administration has been drawn into an ENFit syringe via a bottle adapter or ENFit straw, if the dose is given orally and not connected to a feeding tube, the patient will not receive the full amount of liquid, and thus an incomplete dose. This is because fluid will remain in the dead space after delivering the medication into the patient’s mouth (Figure 7). For volumes above 2 mL, this would not be clinically significant since only 0.15 mL to, at most, 0.2 mL would remain (under 10%). Most liquid doses for adults are usually well above that amount, so this should rarely be a problem for them. However, for neonatal, infant, and some pediatric patients, this could represent a significant underdosing, especially since some infant liquid medication doses can be under 0.25 mL (e.g., concentrated morphine, digoxin, and others). When infants, small children, or others are receiving very small volumes of liquid orally, we recommend using oral syringes for oral doses.
Finally, if an ENFit syringe by itself (no straw) is used by nurses to draw up liquid from a unit dose cup for oral use, the bubble should be removed and the syringe should be completely filled to the appropriate dose, keeping the fluid that accumulates in the syringe tip dead space. This same amount will remain in the dead space after releasing the medicine into the mouth. Therefore, a dosing error will not result.
A timely system must be established to notify the pharmacy of all medication doses needed via ENFit syringes due to feeding tubes (or oral syringes when feeding tubes are discontinued). For example, prescribers should be required to order medications by the correct route (i.e., oral, enteral) so the pharmacy knows what type of syringe to use. There should also be other ways to communicate route of administration, such as via electronic messaging. However, in practice, this may be difficult to reliably implement and align with the type of syringe the pharmacy dispenses. Even with such a policy, hospitals should anticipate that some rework will occasionally be needed. Of course, the route of administration should always be reflected in the medication administration record.
A Note About Proprietary Enteral Systems
Devices meant specifically for the neonatal population that do NOT meet the ISO 80369-3 standard for enteral connectors, but have their own proprietary design, are also on the market. These devices will not connect to small bore Luer connectors. However, concern has been expressed that hospitals may not have a fallback system to rely on if a shortage or recall of manufacturer-specific equipment occurs since the proprietary system would not be compatible with ISO-designed ENFit connectors.
If an ENFit syringe is connected to an ENFit bottle adapter or straw for syringe filling, then it must be attached to an ENFit feeding tube in order to administer an accurate dose, particularly liquid doses under 2 mL. If an ENFit syringe is filled directly from a cup without an ENFit straw, then as long as it is not connected to an ENFit device for administration, and instead is delivered directly into the patient’s mouth, the dose will be accurate. Problems can exist if an ENFit adapter or straw is used to fill the syringe with small amounts of medicine but the dose is given orally. Problems can also exist if liquid is drawn directly into a syringe from a cup (no straw) then attached to an ENFit feeding tube. The key point to remember is that the volume in the tip of the syringe (the dead space) before and after administration needs to be the same. If the tip is full of medicine before administration, it must be full after administration. If the tip is empty before administration, it must be empty after administration (Figures 8-11).
We urge product vendors to make samples of ENFit syringes, caps, bottle adapters, feeding tubes, straws, and administration sets available as soon as possible. Companies have yet to announce when the enteral devices will be available, but delivery of the samples must be well in advance of new supplies of ENFit devices to allow for evaluation by staff and training. It is only through simulations that practitioners will fully understand the issues described above and pinpoint where errors may happen based on hospital practices. Time for staff inservicing before actual use is also needed, and that can’t be done adequately without seeing the supplies that will be used. Of utmost importance is the ability for frontline nurses, pharmacists and technicians to examine the devices. During the development of future products, early versions of the products should be tested by frontline personnel so potential problems can be identified during development rather than when products are about to reach the market.
We also urge GEDSA companies to work closely with each other and with frontline practitioners to understand how these devices will be used in practice. This will require a lot of hard work on everyone’s part in order to reduce the risk of dosing errors when using the new devices. In the end, though, this is a worthwhile endeavor to eliminate the risk of tragic errors in which enteral liquids are given by the wrong route.
ISMP expresses our gratitude to NeoMed for providing us with samples of the new ENFit devices for simulation in preparing this article. We would also like to express our appreciation to Jamie Sklar, RN, MS, CCRN, and Sean O’Neill, PharmD, both from The Children’s Hospital of Philadelphia, for their assistance during preparation of this article.