Improving early identification of the high-risk elderly trauma patient by emergency medical services

Abstract

Study objective: We sought to (1) define the high-risk elderly trauma patient based on prognostic differences associated with different injury patterns and (2) derive alternative field trauma triage guidelines that mesh with national field triage guidelines to improve identification of high-risk elderly patients.

Methods: This was a retrospective cohort study of injured adults ≥65 years transported by 94 EMS agencies to 122 hospitals in 7 regions from 1/1/2006 through 12/31/2008. We tracked current field triage practices by EMS, patient demographics, out-of-hospital physiology, procedures and mechanism of injury. Outcomes included Injury Severity Score≥16 and specific anatomic patterns of serious injury using abbreviated injury scale score ≥3 and surgical interventions. In-hospital mortality was used as a measure of prognosis for different injury patterns.

Results: 33,298 injured elderly patients were transported by EMS, including 4.5% with ISS≥16, 4.8% with serious brain injury, 3.4% with serious chest injury, 1.6% with serious abdominal-pelvic injury and 29.2% with serious extremity injury. In-hospital mortality ranged from 18.7% (95% CI 16.7-20.7) for ISS≥16 to 2.9% (95% CI 2.6-3.3) for serious extremity injury. The alternative triage guidelines (any positive criterion from the current guidelines, GCS≤14 or abnormal vital signs) outperformed current field triage practices for identifying patients with ISS≥16: sensitivity (92.1% [95% CI 89.6-94.1%] vs. 75.9% [95% CI 72.3-79.2%]), specificity (41.5% [95% CI 40.6-42.4%] vs. 77.8% [95% CI 77.1-78.5%]). Sensitivity decreased for individual injury patterns, but was higher than current triage practices.

Conclusions: High-risk elderly trauma patients can be defined by ISS≥16 or specific non-extremity injury patterns. The field triage guidelines could be improved to better identify high-risk elderly trauma patients by EMS, with a reduction in triage specificity.

Keywords: Elderly; Emergency medical services; Trauma; Trauma systems; Triage.

Figure 1

Frequency and mortality for different definitions of “serious injury” in injured patients over 65 years transported by EMS (n = 33,298).

Figure 2

Alternative out-of-hospital method for identifying older adults with Injury Severity Score ≥ 16 (validation sample n = 13,401). *Including high-risk mechanism (fall, motor vehicle occupant, auto vs. pedestrian/bicycle, significant medical illness, or suffocation) as a separate triage criterion following the “abnormal vital signs” step increased sensitity (99.8%) with a severe decrease in specificity (1.6%). Coupling abnormal vital signs with high-risk mechanisms at this step slightly decreased sensitivity (90.4%), but increased specificity (48.5%). †Patient choice (patients requesting a specific hospital) was considered as an additional predictor in decision rule derivation. This factor was not predictive of patients with ISS ≥ 16 or serious chest injuries. However, the lack of patient choice (hospitals selected by EMS for reasons other than patient choice) increased the probability of having serious abdominal injury and serious TBI. This factor may represent another aspect to consider in the out-of-hospital risk assessment of older patients.