HL7 ORL_O34 (Lab Order Response for One Specimen) | Integration Soup HL7 Reference Guide

HL7 ORL_O34 Lab Order Response for One Specimen

The lab answers an O33-style specimen-centric order.

HL7 message structure ORL_O34 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

Segment	Name	Required	Repeatable
MSH	Message Header	Yes	No
MSA	Message Acknowledgment	Yes	No
ERR	Error	No	Yes
SFT	Software Segment	No	Yes
NTE	Notes and Comments	No	Yes
ORL_O34.RESPONSE	Response group	No	No
ORL_O34.PATIENT	Patient group	No	No
PID	Patient Identification	Yes	No
ORL_O34.SPECIMEN	Specimen group	Yes	Yes
SPM	Specimen	Yes	No
OBX	Observation/Result	No	Yes
SAC	Specimen Container detail	No	Yes
ORL_O34.ORDER	Order group	No	Yes
ORC	Common Order	Yes	No
ORL_O34.TIMING	Timing group	No	Yes
TQ1	Timing/Quantity	Yes	No
TQ2	Timing/Quantity Relationship	No	Yes
ORL_O34.OBSERVATION_REQUEST	Observation Request group	No	No
OBR	Observation Request	Yes	No
ORL_O34.SPMSAC_SUPPGRP2	Spmsac Suppgrp2 group	No	Yes
SPM	Specimen	Yes	No
SAC	Specimen Container detail	No	Yes

ORL_O34 is the laboratory order response that matches the OML_O33 specimen-centric order pattern. It lets the filler acknowledge a message and, when useful, return specimen, container, and order-level status for the orders grouped under a single specimen.

The response can be short when the lab only needs to say the message was accepted. It can also carry SPM, SAC, ORC, and OBR so the placer can store filler order numbers or specimen/container status.

A small ORL O34 example

MSH|^~\&|LAB|CITYLAB|EHR|CITYHOSP|20260718103003||ORL^O34^ORL_O34|ORL340001|P|2.5.1 MSA|AA|OML330001 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L SPM|1|SPEC330001^EHR|SPEC990001^LAB|BLD^Blood^HL70487 SAC|||TUBE330001^EHR|TUBE990001^LAB ORC|OK|ORD330001^EHR|LAB330001^LAB OBR|1|ORD330001^EHR|LAB330001^LAB|718-7^Hemoglobin^LN ORC|OK|ORD330002^EHR|LAB330002^LAB OBR|2|ORD330002^EHR|LAB330002^LAB|6690-2^White blood cell count^LN

What systems do with it

The lab sends ORL_O34 after it receives and evaluates an OML_O33. The placer uses the response to mark the order accepted, capture filler order numbers, store lab specimen identifiers, or display why the lab rejected part of the request.

If one order in the specimen group is accepted and another is rejected, do not flatten the response into one yes/no flag. Read the ORC values per order.

How to read the structure

The response starts with MSH, MSA, optional ERR, and optional notes. The response group can carry patient identity, then one or more specimen groups with order groups beneath them.

ORL_O34 is useful because it preserves the same specimen-centric shape as OML_O33. That shape is the evidence you need to match orders back to the right physical specimen and container.

Implementation traps

Do not assume MSA-1 AA means every requested order was accepted. A message can be syntactically accepted while individual ORC groups describe more specific outcomes.

Also make sure your placer stores returned filler identifiers. Without them, later result messages and cancellations may be harder to reconcile.

Reference notes

The HL7 ORL_O34 structure shows a response with MSH, MSA, ERR, patient, specimen, container, order, timing, and observation request groups. See HL7 Europe ORL_O34.