Beware of Intra-Abdominal Injuries Caused by Seat Belts Predictive Indicators for Bowel Injury in Pediatric Patients Who Present With a Positive Seat Belt Sign After Motor Vehicle

Background: The term "seat belt sign" was originally coined in 1962 and refers to the pattern of bruising on the chest or abdominal wall of a victim of a motor vehicle collision (MVC) that corresponds to the position of the lap or shoulder belt. Objective: To study clinical and radiographic predictors of the need for surgery in pediatric patients with this finding. Participants/Methods: This was a retrospective review of patients involved in MVCs who were found to have abdominal wall bruising (AWB) and were admitted from 1998 to 2008 to a tertiary pediatric trauma center in Montreal. A wide range of clinical information was examined including demographics, vital signs, physical examination findings, radiographic studies, associated injuries, in-hospital management, and outcome. Results: 53 children (median age, 9 years; range, 3 to 16 years) were included in the study. More than 80% had abdominal pain on arrival, and on an initial ultrasound or CT scan, nearly half (25/53) had free intraabdominal fluid. Fifty-five percent of patients with AWB had intra-abdominal injuries. The most common injuries (in 25%) were mesenteric or bowel injuries. Thirteen percent had splenic injuries and 8% had liver injuries. One out of every 5 patients (10/53) needed a therapeutic laparotomy. These patients had abdominal pain, free intra-abdominal fluid, and tachycardia. Patients, who required surgery for an intra-abdominal problem, were much more likely to have a lumbar fracture compared to those who did not require surgery (50% vs 4%). The factors predictive of intestinal perforation in those with AWB included a heart rate >120 per minute, lumbar fracture, and free intra-abdominal fluid; 98% of the children survived their injuries, with only 1 death due to associated head trauma. Conclusions: In pediatric patients with AWB after an MVC, intra-abdominal injuries are frequent. In patients with free fluid, an elevated pulse, and an associated lumbar fracture, an abdominal exploration should be considered because these 3 factors are significant predictors of intestinal injuries. Reviewer's Comments: Most of us will not be at the forefront when the initial evaluation of an MVC occurs. But, if you are, note that AWB is associated with a significantly increased likelihood of intra-abdominal injury (55% in this study). Whenever you see families, remind them that in order to minimize problems with seat belt injuries, children should be in booster seats to assure that the lap and shoulder belts fit properly per AAP guidelines until the child is approximately 4 feet, 9 inches tall, which occurs between 8 and 12 years of age. (Reviewer-Mark F. Ditmar, MD).