Low probability of Significant Intra-Abdominal Injury in Stable Patients with Abdominal ''Seat Belt Sign''

Prevalence of intra-abdominal injury among patients with seatbelt signs, a systematic review and meta-analysis

INTRODUCTION

The advancement of seat belts have been essential to reducing morbidity and mortality related to motor vehicle collisions (MVCs). The "seat belt sign" (SBS) is an important physical exam finding that has guided management for decades. This study, comprising a systematic review and random-effects meta-analysis, asses the current literature for the likelihood of the SBS relating to intra-abdominal injury and surgical intervention.

METHODS

PubMed and Scopus databases were searched from their beginnings through August 4, 2023 for eligible studies. Outcomes included the prevalence of intra-abdominal injury and need for surgical intervention. Cochrane's Risk of Bias (RoB) tool and the Newcastle-Ottawa Scale (NOS) were applied to assess risk of bias and study quality; Q-statistics and I2 values were used to assess for heterogeneity.

RESULTS

The search yielded nine observational studies involving 3050 patients, 1937 (63.5%) of which had a positive SBS. The pooled prevalence of any intra-abdominal injury was 0.42, (95% CI 0.28-0.58, I2 = 96%) The presence of a SBS was significantly associated with increased odds of intra-abdominal injury (OR 3.62, 95% CI 1.12-11.6, P = 0.03; I2 = 89%), and an increased likelihood of surgical intervention (OR 7.34, 95% CI 2.03-26.54, P < 0.001; I2 = 29%). The measurement for any intra-abdominal injury was associated with high heterogeneity, I2 = 89%.

CONCLUSION

This meta-analysis suggests that the presence of a SBS was associated with a statistically significant higher likelihood of intra-abdominal injury and need for surgical intervention. The study had high heterogeneity, likely due to the technological advancements over the course of this study, including seat belt design and diagnostic imaging sensitivity. Further studies with more recent data are needed to confirm these results.

Do signs of abdominal wall injury on computed tomography predict intra-abdominal injury in trauma patients with a seatbelt sign?

BACKGROUND

A seatbelt sign in patients with blunt abdominal injury is associated with both abdominal wall and intra-abdominal injuries. This study aimed to assess the association between signs of abdominal wall injury on computed tomography (CT) and rates of intra-abdominal injury in patients with a blunt abdominal injury and a clinical seatbelt sign.

METHODS

This study includes hemodynamically stable trauma patients with blunt abdominal injury and a clinical seatbelt sign who were hospitalized in two regional trauma centers in Israel, during 2014-2019. All data were collected via the medical center's trauma registry in both centers.

RESULTS

We identified 123 stable blunt abdominal trauma patients with a seatbelt sign, of which 101 (82.1%) and 22 (17.9%) had a low-grade and high-grade abdominal wall injury according to CT findings, respectively. Laparotomy rates were significantly higher in patients with signs of high-grade abdominal wall injury (p<0.0001). No differences in the timing of laparotomy between low and high-grade injuries were found.

CONCLUSIONS

In stable patients with blunt abdominal trauma and a clinical seatbelt sign, the severity of abdominal wall injury, as represented by CT findings, may predict a need for surgical treatment.

A radiographic and physical analysis of factors affecting seat belt position in sitting car seat

The characteristic subcutaneous hemorrhage along the seat belt in motor vehicle accidents is called the seat belt sign (SBS). The risk of organ injuries is especially high when abdominal SBS is located above the anterior superior iliac spine (ASIS). The purpose of this study analyzed the physical and radiographic factors of healthy volunteers sit on car seat that affect initial position of abdominal seat belt, namely "lap belt", related to the seat belt injury. This study was examined prospectively relation between physical characteristics of one hundred healthy volunteers and lap belt position sitting the car seat. Physical findings were clarified age, sex, height, body mass index (BMI), and waist circumference. Radiographical findings were measured lumber lordosis (LL), sacral slope (SS), and initial lap belt position by marking with lead tape for the center and ASIS of the lap belt installed on the driver's car seat. In the lateral X-ray image, we measured the horizontal distance (X-value) and vertical distance (Z-value) from the ASIS to the central marker. The lap belt angle was determined to measure the angle between the horizontal line and the straight line connecting the upper edges of the markers. Statistical analysis of the relationships between physical characteristics and radiological findings was performed. X-value and Z-value were positively correlated with body weight, BMI, and waist circumference, while the lap belt angle was negatively correlated with body weight, BMI, and waist circumference. The relationship between physical characteristics and the initial position of seat belt was analyzed. Since the lap belt is positioned higher than the ASIS in occupants with a high BMI, it is likely to cause seat belt injury. This analysis can help to develop safer seat belts and to enlighten car occupants.

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

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.

Obesity is associated with a reduced odds for blunt intra-abdominal injuries in children

OBJECTIVES

Children with obesity may possess unique injury characteristics that may affect their emergency care. To better understand this relationship, we investigated the association of obesity in pediatric trauma patients and intra-abdominal injuries (IAIs) and routinely utilized emergency department (ED) diagnostic procedures (computed tomography (CT) scans and ultrasound (US) examinations).

METHODS

This secondary data analysis utilized Pediatric Emergency Care Applied Research Network (PECARN) data from 2007 to 2010. Since height data were not available, children (2-17 years) with obesity were defined using weight-for-age percentiles. Non-parametric testing determined potential confounders. Adjusted odds ratios (aOR) were calculated using binary logistic regression for weight status and IAIs and diagnostic procedures.

RESULTS

There were 3846 patients with actual weight recorded: 3301 (85.8%) children without obesity and 545 (14.2%) with obesity. Children with obesity had decreased odds for IAI after adjusting for race, mechanical force injury (MFI) type, vomiting, and abdominal wall trauma (adjusted odds ratio (aOR)=0.58 (95% CI 0.35-0.97); p-value=0.04). Patients with obesity had reduced odds for a CT examination. No association was found between obesity status and US utilization. African-American patients had decreased odds for IAIs, CT scans and US examinations after adjustment which could be related to MFI type.

CONCLUSIONS

Obesity appears to reduce the odds for pediatric IAIs and CT scans, but not for US examinations. Selection bias is possible due to injury severity and missing or excluded weight data. Further research is needed in other pediatric populations with obesity and blunt injuries.

Physical Examination is the Best Predictor of the Need for Abdominal Surgery in Children Following Motor Vehicle Collision

BACKGROUND

Exploratory laparotomy in children after motor vehicle collision (MVC) is rare. In the absence of definitive hemorrhage or free abdominal air on radiographic imaging, predictors for operative exploration are conflicting.

OBJECTIVE

The purpose of this study was to explore objective findings that may aid in determining which children require operative abdominal exploration after MVC.

METHODS

Data from 2010-2014 at an American College of Surgeons-certified level 1 pediatric trauma center were retrospectively reviewed. Demographics, vital signs, laboratory data, radiologic studies, operative records, associated injuries, and outcomes were analyzed and p < 0.05 was considered statistically significant.

RESULTS

Eight hundred sixty-two patients 0-18 years of age presented to the hospital after an MVC during the study period. Seventeen patients (2.0%) required abdominal exploration and all were found to have intraabdominal injuries. Respiratory rate was the only vital sign that was significantly altered (p = 0.04) in those who required abdominal surgery compared with those who did not. Physical examination findings, such as the seat belt sign, abdominal bruising, abdominal wound, and abdominal tenderness, were present significantly more frequently in those requiring abdominal surgery (p < 0.0001). Each finding had a negative predictive value for the need for operative exploration of at least 0.98. There were no significant differences in trauma laboratory values or radiographic findings between the 2 groups.

CONCLUSION

Data from this study solidify the relationship between specific physical examination findings and the need for abdominal exploration after MVC in children. In addition, these data suggest that a lack of the seat belt sign, abdominal bruising, abdominal wounds, or abdominal tenderness are individually predictive of patients who will not require surgical intervention.