Tag Archives: mortality

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.

The ACS “Gang Of 6” Trauma Activation Criteria

For more than 10 years, all trauma centers verified by the American College of Surgeons (ACS) have been required to have a group of mandatory criteria for their highest level of trauma activation. I call these the gang of 6 (ACS-6). They are:

  1. Hypotension (systolic < 90 torr for adults, age specific for children)
  2. Gunshot to neck, chest, abdomen or extremities proximal to elbow or knee
  3. GCS < 9 from trauma
  4. Transfer patients receiving blood to maintain vital signs
  5. Intubated patients from scene or patients with respiratory compromise transferred in (may already be intubated but still having compromise)
  6. Emergency physician discretion

For the most part, it seems obvious that any one of these criteria would indicate a seriously injured patient needing rapid trauma team evaluation. But do all centers use these criteria?

The answer, detailed in a recently published paper, would seem to be no! Researchers at the Universities of Minnesota and Michigan looked at the Trauma Quality Improvement Program database for all Level I and II centers in Michigan over a three year period. They specifically analyzed the data to determine how many centers used all 6 criteria, and any differences in mortality between those that did and those that didn’t. They reviewed records for adults with blunt and penetrating trauma with an ISS > 5.

Here are the factoids:

  • More than 50,000 patient records were reviewed, and 12% met at least one of the ACS-6
  • Only 66% of patients with at least one ACS-6 criterion were full trauma activations (!!)
  • Compliance was poorest with hypotension (only half activated), compared to intubation (75%), central gunshot (75%), and coma (82%)
  • 79% of patients meeting any ACS-6 criterion needed an intervention, with a third going emergently to the OR
  • Undertriaged patients (ACS-6 with no high level activation) were significantly more likely to die (30% vs 21%), and this was most pronounced in the coma group (47% vs 40%)

Bottom line: Physiologic trauma activation criteria are important, as is the central gunshot one! Although this is a database review subject to the usual flaws (retrospective, data accuracy), the numbers are large and the statistics are sound. And remember, this is an association study, so we don’t really know why the mortality numbers were different, just that they were.

Nevertheless, there is a lot to learn from it. Why don’t all centers use the ACS-6? They certainly have them in their criteria list, or they would have failed their verification visit. It’s because of undertriage! How does this happen? Two ways: either the information in the field is incorrect (GCS may be incorrectly estimated, hypotension may be transient), or personnel in the ED failed to activate properly.

This study shows the importance of rigidly adhering to the criteria. It found a 20% mortality reduction if all of the ACS-6 were applied properly. So make sure that your own trauma program regularly monitors for undertriage, especially with respect to the “gang of 6”!

Related posts:

Reference: Noncompliance with American College of Surgeons Committee on Trauma recommended criteria for full trauma team activation is associated with undertriage deaths. J Trauma 84(2):287-294, 2018.

Trauma Mortality vs Cancer Mortality from CT Scans for Trauma

Trauma professionals worry about radiation exposure in our patients. A lot. There are a growing number of papers dealing with this topic in the journals every month. The risk of dying from cancer due to CT scanning is negligible compared to the risk from acute injuries in severely injured patients. However, it gets a bit fuzzier when you are looking at risk vs benefit in patients with less severe injuries. Is it possible to quantify this risk to help guide our use of CT scanning in trauma?

A nice paper from the Mayo clinic looked at their scan practices in 642 adult patients (age > 14) over a one year period. They developed dose estimates using a detailed algorithm, and combined them with data from the Biological Effects of Ionizing Radiation VII data. The risk level for injury was estimated using their trauma team activation criteria. High risk patients met their highest level activation criteria, and intermediate risk patients met their intermediate level activation criteria.

Key points in this article were:

  • Average radiation dose was fairly consistent across all age groups (~25mSv)
  • High ISS patients had a significantly higher dose
  • Cumulative risk of cancer death from CT radiation averaged 0.1%
  • This risk decreased with age. It was highest in young patients (< 20 yrs) at 0.2%, and decreased to 0.05% in the elderly (> 60 yrs)

Bottom line: Appropriate CT scan use in trauma evaluation is challenging. It’s use is widespread, and although it changes management it has not decreased trauma mortality. This paper shows that the risk of death from trauma in the elderly outweighs the risk of death from CT scan radiation. However, this gap narrows in younger patients with less serious injuries because of their very low mortality rates. Therefore, we need to focus our efforts to reduce radiation exposure on our young patients with minor injuries.

Related posts:

References:

  • Comparison of trauma mortality and estimated cancer mortality from computed tomography during initial evaluation of intermediate-risk trauma patients. J Trauma 70(6):1362-1365, 2011.
  • Health risks from low levels of ionizing Radiation: BEIR VII, Phase 2. Washington DC: The National Academies Press, 2006.

Trauma Mortality vs Cancer Mortality from CT Scans for Trauma

Trauma professionals worry about radiation exposure in our patients. A lot. There are a growing number of papers dealing with this topic in the journals every month. The risk of dying from cancer due to CT scanning is negligible compared to the risk from acute injuries in severely injured patients. However, it gets a bit fuzzier when you are looking at risk vs benefit in patients with less severe injuries. Is it possible to quantify this risk to help guide our use of CT scanning in trauma?

A nice paper from the Mayo clinic looked at their scan practices in 642 adult patients (age > 14) over a one year period. They developed dose estimates using a detailed algorithm, and combined them with data from the Biological Effects of Ionizing Radiation VII data. The risk level for injury was estimated using their trauma team activation criteria. High risk patients met their highest level activation criteria, and intermediate risk patients met their intermediate level activation criteria.

Key points in this article were:

  • Average radiation dose was fairly consistent across all age groups (~25mSv)
  • High ISS patients had a significantly higher dose
  • Cumulative risk of cancer death from CT radiation averaged 0.1%
  • This risk decreased with age. It was highest in young patients (< 20 yrs) at 0.2%, and decreased to 0.05% in the elderly (> 60 yrs)

Bottom line: Appropriate CT scan use in trauma evaluation is challenging. It’s use is widespread, and although it changes management it has not decreased trauma mortality. This paper shows that the risk of death from trauma in the elderly outweighs the risk of death from CT scan radiation. However, this gap narrows in younger patients with less serious injuries because of their very low mortality rates. Therefore, we need to focus our efforts to reduce radiation exposure on our young patients with minor injuries.

Related posts:

References:

  • Comparison of trauma mortality and estimated cancer mortality from computed tomography during initial evaluation of intermediate-risk trauma patients. J Trauma 70(6):1362-1365, 2011.
  • Health risks from low levels of ionizing Radiation: BEIR VII, Phase 2. Washington DC: The National Academies Press, 2006.

Lack of EMS Documentation is Associated With Increased Mortality

EMS policy and the trauma center verification process requires that all trauma patients delivered to a trauma center must have a copy of the EMS run sheet. Two parameters that are commonly used to monitor performance improvement (PI) in EMS are:

  • accurate record of scene physiology (SBP, HR, RR, GCS)
  • request by on-scene BLS for ALS assistance

A study looked at the impact of those criteria on patient survival. A total of 4744 patients from the National Trauma Data Bank were analyzed.

Physiologic data: About 28% had at least one missing physiologic data point, with respiratory rate being most commonly missed. They found that the mortality in the group with missing data was over twice as high (10.3%) as it was in the group with complete date (4.5%).

BLS call for ALS assistance: This assist was called for in 17% of cases. These cases were less likely to involve penetrating injuries and more likely to involve car or motorcycle crashes. Injury Severity Score was the same. Eventual patient mortality was the same for BLS calling ALS and ALS response alone.

So why does failure to record physiologic data translate into higher mortality? The initial response may be that the patient was sicker, and so they needed more intense care during transport with less time to record vitals. However, the researchers controlled for this and found it was not a factor. Other issues that may be a factor are EMS training and proficiency, leadership at the scene and enroute, and available staff and resources, among other things.

The researchers speculate that documentation might be a good global measure of appropriate or inappropriate prehospital care that rolls all of these possible factors into one easily identifiable audit filter. They recommend that this be used to focus performance improvement efforts and hopefully improve survival.

I recommend that the results of this study be taken to heart and used to help persuade EMS programs to get religious about recording complete vital signs and leaving the run sheet at the trauma center every time a patient is delivered. Documentation should be evaluated regularly, and all cases with any missing vital signs should be reviewed closely. Trauma Center PI programs should work with EMS to analyze this data and look for the patterns that increase mortality.

Reference: Lack of Emergency Medical Services documentation is associated with poor patient outcomes: a validation of audit filters for prehospital trauma care. Journal of the American College of Surgeons, 210(2):220-227, 2010.