HL7
Health Level 7, set of international standards
Old version 2.x (non-XML):
MSH header segment
PID Patient identity
PV1 patient visit information
Tilde ~ default repetition separator
Caret ^ component separator
Pipe | field separator
Ampersand & for subcomponent separator
ADT A01 message type and triggerm used when a patient is admitted
ADT A02 when patient is changing location
The new patient location should appear in PV1-3 - Assigned Patient Location while the old patient location should appear in PV1-6 - Prior Patient Location. For example, an A02 event can be used to notify: laboratory, radiology, pathology that the patient has changed location and test results should be redirected; pharmacy that drugs should be redirected for the patient; dietary that the meals should be delivered to a different location; the clinical repository that a transfer has taken place for the Electronic Medical Record
Use ADT A09 when patient is moving to a temp location (like hallway)
ADT A08 used when patient information is changed, such as address or name change, when no other trigger is needed
OBR
MSH (header) contains the type and trigger information
ACK is the expected response after system receives an HL7 message (as opposed to NACK?)