ADT^A22 — Patient Returns from a 'Leave of Absence'
The patient is back: A22 reactivates the encounter suspended by A21 and triggers the resumption of scheduled care (pharmacy, biology, planning).
Purpose
LOA return notifies: pharmacy to resume doses, LIS to reinstate suspended biology orders, nursing roster to reintegrate the patient. PV1-3 reflects the location (often same as departure), PV1-19 (visit number) stays stable from A01.
Segment structure
Structure ADT_A21 shared with A21. MSH, EVN, PID, PV1.
Real-world example
Patient John Doe returns on 19 May at 18:00 to bed 205A:
MSH|^~\&|HIS|HOSP01|EHR|CLINIC02|20260519180000||ADT^A22^ADT_A21|MSG00022001|P|2.5.1|||AL|NE
EVN|A22|20260519180000|||DRJONES^Jones^Sarah^^^DR.
PID|1||MRN567890^^^HOSP^MR||DOE^JOHN^A^^MR.||19720515|M
PV1|1|I|MED^205^A^HOSP01|EM|||DRSMITH^Smith^James^A^^DR.|||MED|||1|||DRSMITH|ADM|||||||||||||||||||HOSP01|||||20260514102530Acknowledgment (ACK)
MSH|^~\&|EHR|CLINIC02|HIS|HOSP01|20260519180001||ACK^A22^ACK|ACK00022001|P|2.5.1
MSA|AA|MSG00022001Common errors
- A22 with no prior A21: orphan message — the EHR has nothing to "resume".
- PV1-3 different: if the patient returns to a different bed, A22 + A02 are needed.
- PV1-19 changed: breaks encounter continuity with the original A21.
Related ADT events
| Code | Trigger event | Description |
|---|---|---|
| A21 | Patient Goes on LOA | Starts LOA. |
| A22 | Patient Returns from LOA | This page. |
| A52 | Cancel LOA | Cancellation of A21. |
| A53 | Cancel Return from LOA | Cancellation of A22. |