HL7 v2 RXR-3 Field Guide: Administration Device Values and Common Mistakes
Two doses can share the exact same route and site and still need to be told apart by RXR-3 — a syringe and an auto-injector both deliver a drug intramuscularly, but downstream inventory and safety systems care which one was actually used.
RXR-3 is a coded element (CE/CWE) identifying the physical device used to deliver a dose, such as a syringe, an infusion pump, a nebulizer, or an auto-injector. It's most often populated for injected and infused routes, where the delivery mechanism affects dosing accuracy, inventory tracking, or safety reporting, and is commonly left blank for routes like oral where no device applies.
What this field contains
Example
RXR-3 carries SY^Syringe^HL70164, identifying the delivery device used for the paired intramuscular dose.
Where this trips people up
Because most synthetic and hand-built test messages default to a syringe, systems that key inventory deductions or safety alerts off RXR-3 rarely get tested against pump or nebulizer values until a real infusion feed arrives. The result is code that assumes a 1:1 relationship between route and device — treating every IV entry as pump-delivered, for instance — and breaks the first time an IV push administration shows up with a syringe instead. Testing needs to cover device values that don't match the 'obvious' pairing for a given route.