Patients with Abrasion or Ecchymosis Seat Belt Sign Have High Risk for Abdominal Injury, but Initial Computed Tomography is 100% Sensitive

J Emerg Med. 2020 Oct;59(4):491-498. doi: 10.1016/j.jemermed.2020.06.057. Epub 2020 Aug 18.


Background: Trauma providers seek to accurately assess the risk of patients with abdominal seat belt sign (ASBS). As hospital costs continue to rise, identification of strategies to safely discharge emergency department (ED) patients has become crucial.

Objectives: The purpose of this study is to 1) describe a large cohort of patients by type of ASBS and 2) determine the value of computed tomography (CT) of the abdomen and pelvis as a screening tool to rule out intra-abdominal injury (IAI) and support discharge of stable patients.

Methods: We conducted a retrospective case series of all patients presenting to our urban, Level I trauma center from 2013-2015. We studied motor vehicle collision patients who presented with ASBS. We further classified individuals into ASBS groups: Abrasion, Ecchymosis, Abrasion + Ecchymosis, or Unknown ASBS to examine differences between groups.

Results: In one of the largest described cohorts, the ASBS remained associated with IAI, most commonly, solid organ injury. Of 425 patients, 36.1% had some IAI on CT, but only 13.6% required laparotomy. Categorizing the type of skin injury in ASBS, we found that both abrasion and ecchymosis were associated with IAI. Initial CT performed with 100% sensitivity.

Conclusions: This study shows that ED trauma patients with significant seat belt abrasion or contusion can have IAI. With the very high sensitivity of modern abdominal CT scanners, clinicians could consider safe ED discharge of stable ASBS patients while providing strong return precautions. Our large cohort strengthens the evidence on decision-making in ASBS patients to ensure outcomes and use of health care resources.

Keywords: abdominal/gastrointestinal; clinical guidelines; medical imaging; seat belt sign.

MeSH terms

  • Abdominal Injuries* / etiology
  • Accidents, Traffic
  • Contusions*
  • Ecchymosis / etiology
  • Humans
  • Retrospective Studies
  • Seat Belts
  • Tomography, X-Ray Computed
  • Wounds, Nonpenetrating* / diagnosis