The Trip Report: Making the Trauma Call
Reviewed This Month
Comparative Analysis of State Trauma Triage Criteria vs. Paramedic Discretion.
Authors: Husty T, Crandall M, Logsdon AR, Burns JB, Chesire DJ, Ebler DJ.
Published in: Prehosp Emerg Care, 2018 Feb 1 [e-pub ahead of print].
This month we review a very interesting manuscript that compares the characteristics and outcomes for two groups of patients transported to a trauma center in Florida. These patients were directed to the trauma center either through use of formal state adult trauma triage criteria or at the treating paramedic’s discretion.
This paper essentially asks whether paramedics should simply follow a predefined criteria word for word, or if they should use their training and experience to determine the most appropriate transport destinations for their patients. I’m sure most of you have strong feelings about which is more appropriate; this manuscript adds some empirical evidence to the discussion.
Many of you are familiar with the CDC’s Guidelines for Field Triage of Injured Patients. These identify vital signs, levels of consciousness, anatomy and mechanisms of injury, and special considerations that should trigger transport to a trauma center. One of the special considerations specified is “EMS provider judgment.” However, the usefulness of paramedic judgment as it relates to the decision to transport to a trauma center has been questioned.
Florida’s trauma triage criteria do not exactly align with the CDC’s. The figure above displays the Florida adult trauma triage criteria. In Florida, a trauma alert should be activated and a patient should be transported to an appropriate trauma center if they present with one or more conditions from the first column or two or more from the second. Florida also allows the activation of a trauma alert and transport to a trauma center based on paramedic discretion.
Because conclusive results haven’t yet been published in the medical literature, the authors used data from a single trauma center to address the study objective (comparing the characteristics and outcomes of trauma patients transported under the Florida criteria vs. at paramedic discretion). This study was a retrospective analysis. The inclusion criteria stated that all patients 18 or older who had a trauma alert activated and were transported to the trauma center would be evaluated. The study period was from January 1, 2007 to December 31, 2014. All data were obtained from the institution’s trauma database. PCR data used in this study was entered into the trauma database by trained registrars.
During the study period, there were over 15,000 patients who had a trauma alert activated and were transported to a trauma center. Of these, 13,963 (92.2%) met Florida’s trauma triage criteria, and 1,188 (7.2%) were transported at paramedic discretion. There were 636 patients who had to be excluded because they either did not have an ED or hospital disposition recorded in the institution’s trauma database.
For those who were able to be assessed, there was no statistically significant difference noted when examining admission dispositions. This is especially interesting because the sickest of the trauma patients met criteria and therefore were not eligible to go by paramedic discretion. This implies there may have been patients needing ICU admission missed by criteria. The p-value for this comparison was 0.2, and as we have mentioned before, a p-value is only considered statistically significant if it is below 0.05.
One interesting result was that 25% of those patients who had a trauma alert activated and were transported to this institution because they met Florida’s criteria were discharged from the ED within 24 hours. Authors included the percentages and frequencies between the groups for admission to the ICU and admission to a general care floor but did not include comparative data for ED discharge within 24 hours (though they indicated the post-ED admission dispositions were similar). While the p-value is important, it does not tell the entire story (as we will see below when we discuss systolic blood pressures). A comparison of overtriage percentages would be very informative.
Differences between patients who met Florida’s criteria and those who were transported due to paramedic discretion appeared when comparing the need for immediate intervention (i.e., surgery): Of those who met Florida’s criteria, 21.4% required immediate intervention, but only 11.7% of those transported because of paramedic discretion required immediate intervention (p < 0.001). Further, there was a statistically significant difference in mortality (p < 0.001). Of those who met Florida’s criteria, 7.5% died, while just 2.2% of those transported due to paramedic discretion died. These results make sense, since most obvious threats to life would likely result in the patient meeting Florida’s trauma triage criteria.
Blood Pressure Differences
The authors also found a statistically significant difference between the groups in systolic blood pressure. Patients with a trauma alert and transport based on medic discretion had an average SBP of 122 mm Hg, while those who met Florida’s criteria had an average SBP of 133 mm HG. The p-value for this comparison was less than 0.001—much lower than 0.05.
Let’s discuss this result a little more. How many of us would consider a SBP difference of 122 vs. 133 to be clinically important? A lot would have to do with what else was going on with the patient, but there is no question, looking at the p-value, that this result is statistically significant. This is why it’s so important for those in our field to be educated consumers of EMS research. Just because a result is statistically significant doesn’t necessarily mean it’s clinically important.
Given a large enough data set (and this one is very large), almost any test can return a statistically significant result. This demonstrates why it’s so important to avoid simply including p-values: Had the authors not included the actual SBP averages in the manuscript, there would be no way for the reader to determine whether the result was truly important or not.
Other important differences included ICU and hospital lengths of stay, with those patients who met Florida’s criteria having a length of stay slightly over two days longer than those transported by paramedic discretion. The p-value for both of these comparisons was less than 0.001. Trauma patients with psychiatric disorders were also less likely to have a trauma alert activated due to paramedic discretion.
The authors also found that when a patient had both increased age and increased heart rate, they were more likely to have a trauma alert activated by PD and be transported to a trauma center when neither met Florida’s criteria. As the authors noted in their discussion, this suggests paramedics understand vital signs alone may not be a good indication of overall injury severity, and they likely recognize injuries have a greater impact on older adults. The authors further noted their results indicate that paramedics “do not use one number in isolation, but instead may be evaluating the components as a unit.”
There are some clear limitations to this study. First, since it only used data from one hospital, the results may not be generalizable to other institutions, statewide, or nationally. The fact that Florida’s trauma triage criteria differ from the CDC’s may further limit relevance outside of Florida. The level of this trauma center is also not clear from the manuscript.
Finally, as the authors note, they were not able to survey paramedics or evaluate the narratives, either of which would help with further understanding the results of this study.
The authors ended their discussion by saying, “We believe that paramedic discretion remains an important adjunct to state activation criteria.” They also call for future research into paramedic discretion to “help refine and codify the elements of paramedic discretion that are predictive of patient outcomes.”
As always, please read this manuscript. It is well written and there is additional information we did not have space to discuss here.
Antonio R. Fernandez, PhD, NRP, FAHA, is research director at the EMS Performance Improvement Center and an assistant professor in the Department of Emergency Medicine at the University of North Carolina–Chapel Hill. He has been a nationally certified paramedic since 2005 and completed the EMS Research Fellowship at the National Registry of Emergency Medical Technicians.