Background: The American College of Surgeons’ (ACS) Committee on Trauma requires trauma centers to use six minimum criteria for full trauma team activation: hypotension; gunshot wound to the neck or torso; GCS < 9; respiratory compromise; transfers receiving blood transfusion; or physician discretion. The accuracy of these criteria is limited, and trauma centers are encouraged to use additional criteria to identify patients who may benefit from trauma surgeon presence in the ED. Our goal was to evaluate the effect of adding varying shock index (SI) thresholds to the minimum criteria in an adult trauma population with the hypothesis that SI would significantly improve sensitivity with an acceptable decrease in specificity.
Methods: We performed a secondary analysis of prospectively-collected EMS and trauma registry data from an urban Level 1 trauma center in Denver, Colorado. Consecutive adult (>15 years of age) patients were included from 1993 through 2008. Shock index (heart rate divided by systolic blood pressure) at thresholds of ≥ 0.8, ≥ 0.9, and ≥ 1 were evaluated. Primary outcome was emergent operative (within 1 hour of arrival) or procedural (cricothyrotomy or thoracotomy) intervention (EOPI); secondary outcome was a composite of EOPI or ISS > 15. Sensitivities, specificities, and 95% CIs were calculated for the ACS minimum criteria alone and in combination with each SI threshold for each outcome.
Results: 20,872 patients were included; 27% had ISS > 15 and 15% with penetrating injures; 42% had a SI ≥ 0.8, 17% had a SI ≥ 1, and 23% met at least one ACS minimum criterion; and 5% underwent EOPI. Sensitivity and specificity of the ACS minimum criteria alone were 87% (95% CI: 84-89%) and 78% (95% CI: 77-78%), respectively. Inclusion of SI thresholds of 0.8, 0.9, and 1 resulted in sensitivities of 95% (95% CI: 94-96%), 92% (95% CI: 90-93%), and 90% (95% CI: 88-92%), respectively, and specificities of 50% (95% CI: 50-51%), 63% (95% CI: 62-63%), and 70% (95% CI: 69-70%), respectively. Similarly, sensitivities significantly increased for EOPI or ISS > 15 with addition of SI to the minimum criteria.
Conclusion: Addition of SI to the ACS minimum criteria for trauma team activation increases sensitivity for EOPI and EOPI or ISS > 15 with an acceptable decrease in specificity. A SI threshold of ≥ 0.9 most closely aligns with under- and overtriage benchmarks commonly cited for trauma triage.