Best of AAST #11: The Need For Trauma Intervention Score (NFTI)

The Trauma Measurement Workgroup at Baylor University in Dallas has been working on a new indicator for identifying major trauma. In a paper published in the Society of Trauma Nursing last year, they determined that six trauma registry variables best identified these patients:

  • transfusion of packed cells within 4 hours of arrival
  • discharge from ED to OR within 90 minutes of arrival
  • discharge from ED to interventional radiology
  • discharge from ED to ICU with a stay > 3 days
  • mechanical ventilation within 3 days, not including OR or procedures
  • death within 60 hours of arrival

Traditionally, Injury Severity Score (ISS) has been used to measure anatomic injury, the Revised Trauma Score (RTS) to quantify physiologic derangement, and their combination (TRISS) to estimate survival.  The authors postulate that physiologic reserve is another determinant of survival, and that NFTI might provide a way to quantify this reserve. One of the QuickShot presentations at the AAST meeting demonstrates how the authors applied this metric.

A multi-institutional data collaborative collected information on more than 88,000 across 35 trauma centers. A complicated mathematical and statistical analysis was carried out, testing how well high ISS (>15), low RTS (<4), and NFTI+ (at least one NFTI variable) predicted mortality, complications, full trauma team activation, length of stay, and procedures performed within 3 days of arrival.

The authors found that NFTI was significantly better at predicting all the outcome variables except full trauma activation than ISS or RTS. And it was still pretty good at that one.

Bottom line: So what does all this mean? The design and analysis of all the numbers is sound. The only thing I take issue with is the assumption that NFTI reflects the “reserve” that a patient has available to combat serious injury. The authors postulate that NFTI is not affected by frailty and comorbidities like ISS and RTS are. I have not seen the manuscript, so perhaps the authors explain the rationale there. But it seems like a stretch. 

What happens if we remove that assumption? Then this study becomes a comparison of a new way to predict resource utilization and/or survival vs ISS and RTS. It uses future variables (as does ISS), so it is difficult to apply this information on patient arrival to treat them any differently, until the first NFTI factor is triggered. But it does predict them well. I think there is considerable potential for NFTI, but we just need more work to make it more useful as early as possible.

Reference: The need for trauma intervention (NFTI) defines major trauma more accurately than injury severity score (ISS) and revised trauma score (RTS): data from a collaboration of 35 adult trauma centers. QuickShot presentation #9, AAST 2018.

Source: The Trauma Professionals’s Blog