Do we have standard for HL7 OBX-4 containment hierarchy - hl7

I am processing HL7 message. OBX-4field gives containment hierarchy.I see different dotted hierarchy in the message.
is there any standard for containment hierarchy dotted number?
For below example. will first dotted 1 always mean MDC_DEV_MON_PHYSIO_MULTI_PARAM_MDS and 2nd dot 5-always mean MDC_DEV_ECG_VMD.
are these number configurable in the medical device.I want to store data uniquely based using MDS/VMD/CHAN.
Right now I am getting HL7 from one source..will these hierarchy will always be same for that source.
is this would be valid if i get hl7 message from other source.
MDC_DEV_MON_PHYSIO_MULTI_PARAM_MDS/MDC_DEV_ECG_VMD/MDC_ECG_HEART_RATE
to Acehive
1.5.0.1
1-MDC_DEV_MON_PHYSIO_MULTI_PARAM_MDS
5-MDC_DEV_ECG_VMD
13-MDC_DEV_METER_PRESS_BLD_VMD
1-MDC_DEV_METER_PRESS_BLD_CHAN
OBX|1||69965^MDC_DEV_MON_PHYSIO_MULTI_PARAM_MDS^MDC|1.0.0.0|||||||X
OBX|2||69798^MDC_DEV_ECG_VMD^MDC|1.5.0.0|||||||X
OBX|3|NM|147842^MDC_ECG_HEART_RATE^MDC|1.5.0.1|88|{beat}/min^{beat}/min^UCUM|||||R|||20200508051804.8340+0530||||DFG~01^^Y71A57FFFE6188F3^EUI-64
OBX|4|NM|148066^MDC_ECG_V_P_C_RATE^MDC|1.5.0.2|7|{beat}/min^{beat}/min^UCUM|||||R|||20200508051804.8340+0530||||DFG~01^^Y71A57FFFE6188F3^EUI-64
OBX|17||69854^MDC_DEV_METER_PRESS_BLD_VMD^MDC|1.13.0.0|||||||X
OBX|18||69855^MDC_DEV_METER_PRESS_BLD_CHAN^MDC|1.13.1.0|||||||X OBX|19|NM|150018^MDC_PRESS_BLD_DIA^MDC|1.13.1.15|68|mm[Hg]^mm[Hg]^UCUM|||||X|||20200508051804.8340+0530||||DFG~01^^Y71A57FFFE6188F3^EUI-64||unknow

This particular HL7 ORU example is a more strict protocol within the HL7 format. It is defined by IHE, and the message type of this example is PCD (Patient Care Device) You can start searching for details of this message format here: https://wiki.ihe.net/index.php/Patient_Care_Device

You'll need to consider things:
HL7 event type of the message, found in MSH.9
If you have the specs of HL7 v2, then you can check on what the segments are usually use and the hierarchy of it.
If you don't have the HL7 spec directly from HL7.org, you'll need to ask the client sending the HL7 message their own spec. Their spec will guide you on how they structured their message. What are repeating, required and optional fields.
HL7 is a loose standard, some organizations don't strictly implement directly what the HL7 spec has, instead they repurpose some of the segments and fields, so it's best to have the client's own HL7 spec. That means other sources of HL7 may have a different approach.
I usually use this link to check on the HL7 definitions: https://hl7-definition.caristix.com/v2/HL7v2.5.1
Based from my experience, OBX segments are repeating and are usually under the OBR segment as child nodes. OBX.2 is the index, which is odd in your message since I see index 4 is followed by index 17.

So far after exploration i understood that those dotted numbers are not standard.Below is IHE documents.
Probably it depends on the profile. which can be different at different point.
https://www.hl7.org/documentcenter/public/wg/healthcaredevices/N0262_WG7_RCH.1g.pdf
I marking it is as answer. I will change this if something better explanation comes.

Related

Can there be discrepancies between ORC and OBR common elements in HL7 ORU messages?

Does anyone know whether it is common to see values in the OBR segment not match the values from similar concepts in the ORC segment for laboratory diagnostic result HL7 ORU messages?
For example:
ORC.7.6 - Priority
OBR.27.6 - Priority
Can it be possible that the ORC shows "routine", but one of the OBR values underneath that shows "stat" for one of a few tests ordered? (So that parsing logic needs to look at OBR first, OCR second to be accurate?)
Similarly, can this same phenomenon happen with the ordering provider?
ORC.12 - Ordering Provider
OBR.16 - Ordering Provider
For example, if a physician orders a Hep B test that comes back as positive, and the lab's middleware has rules that order a reflux test for Surface B antigen or something else automatically, then the original ordering physician isn't who technically placed the reflux order, but the middleware rule. How is this usually expressed between the ORC.12 and OBR.16 segments corresponding to the ordering provider?
(Don't think it's relevant, but we're reading HL7 v2.5.1 ORU messages)
The ORC is Common Order Segment. The OBR is Observation Request Segment.
The data in those respective segments is related to that specific segment. It may or may not be same.

Does the order of segments in HL7 V2 matter?

I know that the order of fields and components matter, but what about the order of segments in an HL7 message?
They all obviously have to have the MSH at the beginning, but is there anything in the HL7 guides that explicitly state that hl7 Segments must be in a particular order.
Certainly, the documentation lists segments in a certain order when describing a message type, but isn't that just the order it was written down? Do you need to have your messages in the same order (other than the grouped items)?
I would have thought that the PID-1 would be irrelevant if the order was set by the order in the message.
I'm keen to hear any opinions, but I would particularly like to hear from someone that can reference some documentation that specifies this.
Yes it does matter -
There is a specific requirement that a required segment be in between two identical segments.
From version 2.5.1 chapter 2:
A named segment X may occur more than once in an abstract message
syntax. This differs from repetition described earlier in this
section.
When this occurs, the following rules must be adhered to:
If, within an abstract message syntax, a named segment X appears in two
individual or group locations, and a) Either appearance is optional or
repeating in an individual location; b) or, either appearance is
optional or repeating, in a group location then, the occurrences of
segment X must be separated by at least one required segment of a
different name so that no ambiguity can exist as to the individual or
group location of any occurrence of segment X in a message instance.
A real world example of this is ROL segments in ADT^A02, one follows PD1, and one follows PV2, but PV1 is required in between the two.
If you're writing some kind of parser though, I would be wary of anyone actually respecting this rule.
Absolutely. The order of segments is defined in the HL7 standard.
For example (I'm using version 2.4 International) section 4.4.1 ORM ‑ general order message (event O01) regarding Order Entry shows the following as the structure of an ORM order message (formatting is not ideal)
ORM^O01^ORM_O01
MSH
[{NTE}]
[
PID
[PD1]
[{NTE}]
[
PV1
[PV2]]
[{IN1
[IN2]
[IN3]
}]
[GT1]
[{AL1}]
]
{
ORC
[
<OBR|RQD|RQ1| RXO|ODS|ODT>
[{NTE}]
[CTD]
[{DG1}]
[{
OBX
[{NTE}]
}]
]
[{FT1}]
[{CTI}]
[BLG]
}
The square brackets indicate possible repetitions, and the curly brackets that segments are optional (for example directly after the MSH you could have 0, 1 or n NTE segments.)
To be a valid ORM message, an OBR segment should come after an ORC segment that itself should come after a PID etc. An OBR segment is thus for example not allowed to be sent before a PID segment (see this as a layer structure, the Observation Request comes under an Order Common segment that itself is related to a Patient Visit that is specific to a Patient.)
The PID-1 field you mentioned is not a good example, as most messages will only have one PID segment, and PID-1 thus be 1. (I'm not aware of messages containing more than one PID segment, please add to the comments if anyone knows concrete examples from the HL7 specs). But if you look at for example OBR-1, there can be multiple Observervation Requests in the same Order message, for example an order for a Kalium and a Natrium, there would thus be a sequence number sent in OBR-1 to ensure data from the different orders are not mixed up, e.g.:
ORC|...
OBR|1|12345||KA^Kalium|...
OBR|2|12346||NA^Natrium|...

Is there a common way to write addresses of facilities in HL7 SIU/ADT messages?

I've found several references to SAD/AD/XAD data types in the HL7 spec, but don't see anything about this info being used to describe facilities, such as those described in the AIL segment (e.g. "2^BLUE HILL FACILITY"). But where, if anywhere, can I expect to get data about that facility, such as name, street address, etc.?
In the PV1 segment definition for HL7 2.x there isn't a dedicated field for Facility Address specifically. If you are the receiving system in this case, you may have to request that data be sent or added in from the sending system. This could be as simple as placing it in the PV1-5.X field (X being whatever subfield the sending system decides on), or adding in a custom Z segment (ZPV for example) to have this data transmitted.
Since there is no standard field for this kind of data in the PV1 segment though, you will have to confirm that the sending system can in fact send this data.
The facility name will be in a separate field. It varies from segment to segment. You just have to read the segment definition and pick the right field.

How to identify HL7 order request(ORM) message corresponding to response message(ORR)

I am into HL7 parser development and still learning HL7. Read articles regarding Orders but still not clear about how to identify the HL7 order request corresponding to HL7 order response message.
Additional Info:
About 'MessageControlId' in MSH segment: The receiving system echoes 'MessageControlId'(10th field of MSH segment) back to the sending system in the Message acknowledgment segment(MSA). By using this ID we can identify the ACK corresponding to the request.
Need to confirm whether response message will also contain this message id.
It would be greatly appreciated if someone could provide some sample ORM and corresponding ORR messages.
The ORM message type was deprecated in version 2.4 and withdrawn in 2.7 so you really shouldn't be using it at all any more. But if you do decide to use it, the matching ORM and ORR messages should have the same value in the ORC-2 (placer order number) field. Note that for a single real world order there may be multiple ORM and ORR messages.

Can an attachment be split in an HL7 file and recreated after the message is transmitted?

I am using the HAPI parser to parse the HL7 files that come through my company. We are working on moving attachments through the OBX segment of the HL7 file. There are some validators that my stack uses that will not allow an attachment over 64k to pass. Is there a way to take multiple OBX segments and break an attachment up and then recreate it after it has passed through the wire to the other side?
HL7 identifies two possible cases and uses continuation pointer protocol for each. These cases are:
A single segment may be too large. HL7 uses the "ADD" segment to handle breaking a single segment into several smaller segments.
A single HL7 message may be too large. HL7 uses the DSC segment (in conjunction with the MSH-14 filed) and the continuation protocol to handle message fragmentation.
Chapter 2 “Controls” of the HL7v2 spec talks about it in more details.

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