Out-of-Hospital Triage of Older Adults With Head Injury: A Retrospective Study of the Effect of Adding "Anticoagulation or Antiplatelet Medication Use" as a Criterion

Abstract

Study objective: Field triage guidelines recommend that emergency medical services (EMS) providers consider transport of head-injured older adults with anticoagulation use to trauma centers. However, the triage patterns and the incidence of intracranial hemorrhage or neurosurgery in these patients are unknown. Our objective is to describe the characteristics and outcomes of older adults with head trauma who are transported by EMS, particularly for patients who do not meet physiologic, anatomic, or mechanism-of-injury (steps 1 to 3) field triage criteria but are receiving anticoagulant or antiplatelet medications.

Methods: This was a retrospective study at 5 EMS agencies and 11 hospitals (4 trauma centers, 7 nontrauma centers). Patients aged 55 years or older with head trauma who were transported by EMS were included. The primary outcome was the presence of intracranial hemorrhage. The secondary outcome was a composite measure of inhospital death or neurosurgery.

Results: Of the 2,110 patients included, 131 (6%) had intracranial hemorrhage and 41 (2%) had inhospital death or neurosurgery. There were 162 patients (8%) with steps 1 to 3 criteria. Of the remaining 1,948 patients without steps 1 to 3 criteria, 566 (29%) had anticoagulant or antiplatelet use. Of these patients, 52 (9%) had traumatic intracranial hemorrhage and 15 (3%) died or had neurosurgery. The sensitivity (adjusted for clustering by EMS agency) of steps 1 to 3 criteria was 19.8% (26/131; 95% confidence interval [CI] 5.5% to 51.2%) for identifying traumatic intracranial hemorrhage and 34.1% (14/41; 95% CI 9.9% to 70.1%) for death or neurosurgery. The additional criterion of anticoagulant or antiplatelet use improved the sensitivity for intracranial hemorrhage (78/131; 59.5%; 95% CI 42.9% to 74.2%) and death or neurosurgery (29/41; 70.7%; 95% CI 61.0% to 78.9%).

Conclusion: Relatively few patients met steps 1 to 3 triage criteria. For individuals who did not have steps 1 to 3 criteria, nearly 30% had anticoagulant or antiplatelet use. A relatively high proportion of these patients had intracranial hemorrhage, but a much smaller proportion died or had neurosurgery during hospitalization. Use of steps 1 to 3 triage criteria alone is not sufficient in identifying intracranial hemorrhage and death or neurosurgery in this patient population. The additional criterion of anticoagulant or antiplatelet use improves the sensitivity of the instrument, with only a modest decrease in specificity.

Figure 1. Guidelines for field triage of injured patients - United States, 2011

* The upper limit of respiratory rate in infants is >29 breaths per minute to maintain a higher level of overtriage for infants. ^† Trauma centers are designated Level I-IV. A Level I center has the greatest amount of resources and personnel for care of the injured patient and provides regional leadership in education, research, and prevention programs. A Level II facility offers similar resources to a Level I facility, possibly differing only in continuous availability of certain subspecialties or sufficient prevention, education, and research activities for Level I designation; Level II facilities are not required to be resident or fellow education centers. A Level III center is capable of assessment, resuscitation, and emergency surgery, with severely injured patients being transferred to a Level I or II facility. A Level IV trauma center is capable of providing 24-hour physician coverage, resuscitation, and stabilization to injured patients before transfer to a facility that provides a higher level of trauma care. ^§ Any injury noted in Step Two or mechanism identified in Step Three triggers a "yes" response. ^¶ Age <15 years. ** Intrusion refers to interior compartment intrusion, as opposed to deformation which refers to exterior damage. ^†† Includes pedestrians or bicyclists thrown or run over by a motor vehicle or those with estimated impact >20 mph with a motor vehicle. ^§§ Local or regional protocols should be used to determine the most appropriate level of trauma center within the defined trauma system; need not be the highest-level trauma center. ^¶¶ Age >55 years. *** Patients with both burns and concomitant trauma for whom the burn injury poses the greatest risk for morbidity and mortality should be transferred to a burn center. If the nonburn trauma presents a greater immediate risk, the patient may be stabilized in a trauma center and then transferred to a burn center. ^††† Patients who do not meet any of the triage criteria in Steps One through Four should be transported to the most appropriate medical facility as outlined in local EMS protocols.

Figure 2. Incidence of outcomes by field triage criteria, n=2110

Abbreviations: TC; Level 1 or 2 trauma center: tICH, acute traumatic intracranial hemorrhage Composite outcome includes in-hospital death or neurosurgery