"Insignificant" mechanism of injury: not to be taken lightly.

Background: Trauma resources should be spent rationally. The mechanism of trauma is used extensively to triage patients to appropriate levels of care. We examine the hypothesis that patients with "insignificant" mechanism of trauma may have major injuries that require expert trauma care.

Study Design: Over 9 months at a high-volume Level I trauma center, a prospective study was done on patients who sustained ground-level falls (GLF), low-level falls (LLF) from less than 10 feet, or were found down (FD) with no external evidence of significant trauma, and required evaluation by the trauma team. Of 301 patients included, 110 (37%) had GLF, 95 (31%) LLF, and 96 (32%) FD. Our main outcomes measure was significant injuries, defined as visceral or intracranial injuries, long-bone, pelvic, facial, or spinal fractures.

Results: One hundred ten patients (37%) had significant injuries, 20 (7%) were admitted to the ICU, 14 (5%) required an operation, and 4 (1%) died. The most common injuries were intracranial and skeletal. Almost all patients were evaluated by CT (95%), but only one-quarter had abnormal findings on it. LLF, age more than 55 years, and the absence of severe intoxication (blood alcohol level of less than 200 mg/dL) were independent risk factors for significant injuries. A statistical prediction model showed that, when all risk factors are present, the probability of significant injuries is 73%; when all risk factors are absent, there is still a 16% chance for significant injuries. Patients with significant injuries had more operations, longer hospital stays, and higher hospitalization costs compared with patients without significant injuries.

Conclusions: Low-energy trauma may produce significant injuries, predominantly intracranial and skeletal. Trauma care providers should be cautious about dismissing such patients based on the trivial mechanism of injury. Patients with LLF who are older than 55 years and not severely intoxicated have a high likelihood for significant injuries. Resources should be spent rationally for patients who do not have these characteristics, because the probability of significant injuries among them is low, but not zero.