^R21
OUL^R21 — Unsolicited Specimen-Oriented Observation
OUL^R21 is a result message sent by the LIS to report completed lab results organized by specimen. It groups all results for a specimen together under an SPM segment, making it ideal for multi-test panels run from a single specimen collection.
When Is This Sent?
LIS sends completed lab results without a prior ORU order request, organized around the specimen rather than individual orders. Commonly used in IHE LTW (Laboratory Testing Workflow) compliant environments.
Real-World Usage
OUL^R21 is the IHE LTW-recommended result message for lab-to-EHR result delivery. By organizing results around the SPM segment, it accurately reflects how lab analyzers process specimens — a single blood draw may yield CBC, BMP, and coagulation results all from one tube. Systems not configured to accept OUL^R21 will reject it; verify the EHR or result receiver supports this message type before deploying.
Message Structure
Segment names link to their field-level reference pages.
| # | Segment | Purpose in this message | Req | Repeat |
|---|---|---|---|---|
| 1 | MSH | Message header with OUL^R21 in MSH.9 | R | — |
| 2 | SPM | Specimen details — the organizing element; all results belong to this specimen | R | Yes |
| 3 | OBR | Observation request — test performed on this specimen | R | — |
| 4 | OBX | Result values | R | Yes |
| 5 | PID | Patient demographics | O | — |
| 6 | PV1 | Visit context | O | — |
| 7 | NTE | Comments at the specimen or result level | O | Yes |
Example Message
Realistic example with fake patient data. Paste into the HL7 Message Viewer to explore interactively.
1MSH||^~\&|LIS|HOSPITAL_A|EPIC|HOSPITAL_A|20260310160000||OUL^R21^OUL_R21|OUL00001|P|2.5.1 2PID||1||123456^^^HOSP_A^MR||Smith^John^M^^Mr.||19850315|M 3SPM||1|SPEC20260310001^LIS||BLDV^Venous blood^HL70487||||||P||||||20260310143205 4OBR||1|ORD20260310001^EPIC|ACC20260310001^LIS|85025^CBC with Auto Differential^CPT4|||20260310143205|20260310160000 5OBX||1|NM|718-7^Hemoglobin^LN||13.2|g/dL|13.5-17.5|L|||F|||20260310160000 6OBX||2|NM|789-8^Erythrocytes^LN||4.1|10*6/uL|4.5-5.5|L|||F|||20260310160000
Troubleshooting Scenarios
EHR receives OUL^R21 but cannot match results to orders
Cause
OBR.2 (placer order number) in the OUL^R21 doesn't match what the EHR issued in its original OML^O21. The filler number is different or the placer number wasn't echoed correctly.
Fix
Verify the LIS is echoing back the exact placer order number (OBR.2) from the original OML^O21. Compare the OBR.2 value in the OUL^R21 with the OBR.2 in the original order. Check for trailing spaces or padding differences.
Results arrive but SPM is empty — specimen details missing
Cause
LIS is populating SPM minimally (SPM.1 only) without specimen type, source, or collection time.
Fix
Work with the LIS team to populate SPM.4 (specimen type using HL7 table 0487) and SPM.18 (specimen received date/time) at minimum. The EHR may require SPM.4 to correctly categorize results.
Common Confusions
OUL^R21 (specimen-organized results) vs ORU^R01 (order-organized results). Both deliver lab results, but OUL^R21 organizes by SPM (specimen) while ORU^R01 organizes by OBR (order request). In IHE LTW workflows, OUL^R21 pairs with OML^O21 orders. In legacy workflows, ORU^R01 is used with ORM^O01 orders. The receiving system must be explicitly configured to handle OUL^R21.
Related Message Types
Segment Reference
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