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HL7 ORU
An HL7 v2 message that carries observation results — diagnostic reports, lab values, and radiology results — back to the system that ordered them.
When to use it
Use ORU to deliver finalized or preliminary results from a producing system (lab, RIS, reporting) to the ordering EMR or downstream consumers.
In plain terms
If the order (ORM) is the request slip, the ORU is the completed report handed back.
Common gotchas
- Result status (OBX-11 / OBR-25) distinguishes preliminary, final, and corrected results — downstream systems must honor it.
- One ORU can bundle many OBX segments; a consumer that reads only the first will miss data.
- ORU commonly rides over MLLP; receiving an ACK does not mean the result was filed.