Patient’s Blood Thinner History Critical to EMS Triage

Adding anticoagulant or antiplatelet use to field triage guidelines for emergency medical services (EMS) could be a clinically important when responding to older adults with head trauma, according to a new study.

Researchers at the University of California Davis, Kaiser Permanente Sacramento Medical Center, and other institutions conducted a retrospective study at five EMS agencies and 11 hospitals involving 2,110 patients aged 55 years or older with head trauma who were transported by EMS to a hospital. The primary outcome was presence of intracranial hemorrhage; the secondary outcome was a composite measure of in-hospital death or neurosurgery.

The results showed that 6% of patients had intracranial hemorrhage, and 2% suffered in-hospital death or neurosurgery. In all, 29% of the patients were taking anticoagulants or antiplatelet medication, with 9% these patients suffering from intracranial hemorrhage, and 3% dying or undergoing neurosurgery. Standard field triage criteria helped correctly identify 19.8% as suffering from traumatic intracranial hemorrhage. Adding a fourth question -- whether the patient is on anti-coagulant therapy -- improved the sensitivity for intracranial hemorrhage to 59.5%. The study was published on February 24, 2017, in Annals of Emergency Medicine.

“While we wait for other studies to confirm our research, we strongly urge patients to make their medication history available and known to their families and EMS providers, especially for situations that may arise where they cannot speak for themselves,” said lead author Daniel Nishijima, MD, MAS, of UCD. “Knowledge of their use of blood thinners may help in getting these patients to the right hospital.”

“Adding a question about the use of blood thinners in older adults to our field triage criteria could save lives,” commented Craig Newgard, MD, MPH, of the Oregon Health & Science University (Portland, USA), in an accompanying editorial. “Older patients suffering head trauma who are taking blood thinners are more likely to suffer from bleeding in the brain that requires time-sensitive surgery at a major trauma center. Current EMS triage criteria do not include that question, but this study suggests that maybe they should.”

The ‘Guidelines for Field Triage of Injured Patients’ include physiologic, anatomic, and mechanism-of-injury criteria designed to help EMS personnel identify injury types and severity in the field, help deliver immediate care, and determine where best to transport the trauma patient. Overall risk of death could be as much as 25% lower for patients treated at Level 1 trauma centers; but Level 1 centers are not necessary for all patients, and deciding where to triage the patient helps ensure that the medical system’s overall assets are used efficiently.