Important note! As called out in a comment at the bottom of the post, this article is based on the 2025 NTDS Data Dictionary. It has recently been updated to the 2026 version, which I do not currently have access to.

There seems to be quite a bit of confusion about the concept of  “unanticipated return to the operating room” among trauma program professionals. Let’s dig into the real definition of this important performance improvement topic.

The most basic definition of an unanticipated return to the operating room (let’s call it URTOR for brevity) is an additional operative procedure not part of the original treatment plan. Also, it must occur after any operation for a similar or related previous procedure performed at your hospital. It does NOT include any staged, pre-planned, or incidental procedures that are part of the initial plan. And if it is due to a procedure from an outside hospital, their PI program needs to run it through their PI process. That one’s not on you.

Here are some straightforward examples:

• The definitive laparotomy stage of a damage control procedure is not unplanned. Nor is a planned second-look procedure to determine bowel viability.
• But if an iatrogenic injury occurs in the ED or ICU that requires operative intervention, that IS a URTOR. This case meets the “prior procedure” caveat that mandates the operative procedure.

Here are some of the other clarifications provided by the ACS that indicate a URTOR:

• Missed injuries leading to an operation. For example, a delayed fracture diagnosis leading to an operation is a URTOR.
• VATS for retained hemothorax is a URTOR.
• Delayed craniectomy for worsening status (neurologic or CT) is a URTOR.

And finally, here is the official algorithm for determining if a trip to OR is a URTOR. Click on the image to see a bigger copy.

Courtesy: ACS TQIP All Hospital Events Algorithms

Bottom Line: Familiarize yourself with the NTDS/TQIP definition of unexpected return to OR. These are important events that must be accurately captured in your trauma performance improvement program!