Abdominal Seatbelt Sign Research Articles

An Abdominal Seat Belt Sign is Associated With Similar Incidence of Hollow Viscus Injury but Increased In-Hospital Mortality in Older Adult Trauma Patients: A PCSA Multicenter Study.

The abdominal seat belt sign (SBS) is associated with an increased risk of hollow viscus injury (HVI). Older age is associated with worse outcomes in trauma patients. Thus, older trauma patients ≥65 years of age (OTPs) may be at an increased risk of HVI with abdominal SBS. Therefore, we hypothesized an increased incidence of HVI and mortality for OTPs vs younger trauma patients (YTPs) with abdominal SBS. This post hoc analysis of a multi-institutional, prospective, observational study (8/2020-10/2021) included patients >18 years old with an abdominal SBS who underwent abdominal computed tomography (CT) imaging. Older trauma patients were compared to YTPs (18-64 years old) with bivariate analyses. Of the 754 patients included in this study from nine level-1 trauma centers, there were 110 (14.6%) OTPs and 644 (85.4%) YTPs. Older trauma patients were older (mean 75.3 vs 35.8 years old, P < .01) and had a higher mean Injury Severity Score (10.8 vs 9.0, P = .02). However, YTPs had an increased abdominal abbreviated-injury scale score (2.01 vs 1.63, P = .02). On CT imaging, OTPs less commonly had intraabdominal free fluid (21.7% vs 11.9%, P = .02) despite a similar rate of abdominal soft tissue contusion (P > .05). Older trauma patients also had a statistically similar rate of HVI vs YTPs (5.5% vs 9.8%, P = .15). Despite this, OTPs had increased mortality (5.5% vs 1.1%, P < .01) and length of stay (LOS) (5.9 vs 4.9 days P < .01). Despite a similar rate of HVI, OTPs with an abdominal SBS had an increased rate of mortality and LOS. This suggests the need for heightened vigilance when caring for OTPs with abdominal SBS.

Abdominal Seat Belt Sign Is Associated with Similar Incidence of Hollow Viscus Injury but Increased Mortality in Trauma in Patients 65 Years and Older: A PCSA Multicenter Study

INTRODUCTION: The abdominal seat belt sign (A-SBS) is associated with increased risk of hollow viscus injury (HVI). Previous studies have shown that older age is associated with worse outcomes in trauma patients. Older adults (65 years or older) may be at increased risk of HVI with A-SBS. Hence, we hypothesized that HVI and mortality is increased in OAs compared with younger patients (younger than 65 years) with A-SBS. METHODS: This multi-institutional, prospective, observational study (August 2020 to October 2021) included patients 18 years or older with an A-SBS who underwent abdominal CT imaging. No patients were excluded. OAs were compared with younger trauma patients with bivariate analyses. RESULTS: There were 754 patients (110 OAs; 644 younger) included from 9 Level I trauma centers. OAs presented with a higher mean injury severity score (10.8 vs 9.0; p = 0.02), although the younger cohort presented with a higher abdominal abbreviated-injury scale score (2.01 vs 1.63; p = 0.02). On CT imaging, OAs were less likely to present with intra-abdominal free fluid (21.7% vs 11.9%; p = 0.02; Table) despite a similar rate of abdominal soft tissue contusion (p > 0.05). Although HVI was comparable in both groups (5.5% vs 9.8%; p =0.15), OAs experienced increased mortality (5.5% vs 1.1%; p < 0.01) and length of stay (5.9 vs 4.9 days; p < 0.01). Table. - Patient Demographics and Presentation Demographics/Presentation Younger (<65) Older Adults (≥65) p Value Age, mean (SD) 35.8 (13.9) 75.3 (7.0) <0.01 Injury Severity Score, mean (SD) 9.0 (8.2) 10.8 (8.8) 0.02 Abdomen Abbreviated Injury Scale, mean (SD) 2.01 (1.09) 1.63 (0.79) 0.02 Glasgow Coma Scale, mean (SDs) 14.6 (1.5) 14.6 (1.6) 0.73 Positive Fast Scan, n (%) 29 (4.5) 7 (6.4) 0.40 Soft Tissue Seat Belt Sign, n (%) 342 (53.9) 60 (55) 0.82 Free fluid, n (%) 139 (21.7) 13 (11.9) 0.02 Hollow viscus injury, n (%) 63 (9.8) 6 (5.5) 0.15 Mortality, n (%) 7 (1.1) 6 (5.5) <0.01 CONCLUSION: Despite a similar rate of HVI, OAs with an A-SBS had an increased rate of mortality and hospital length of stay. To improve quality of care in this population, there should be heightened vigilance when caring for OAs presenting with A-SBS.

Body mass index influence on lap belt position and abdominal injury in frontal motor vehicle crashes

Objective As obesity rates climb, it is important to study its effects on motor vehicle safety due to differences in restraint interaction and biomechanics. Previous studies have shown that an abdominal seatbelt sign (referred hereafter as seatbelt sign) sustained from motor vehicle crashes (MVCs) is associated with abdominal trauma when located above the anterior superior iliac spine (ASIS). This study investigates whether placement of the lap belt causing a seatbelt sign is associated with abdominal organ injury in occupants with increased body mass index (BMI). We hypothesized that higher BMI would be associated with a higher incidence of superior placement of the lap belt to the ASIS level, and a higher incidence of abdominal organ injury. Methods A retrospective data analysis was performed using 230 cases that met inclusion criteria (belted occupant in a frontal collision that sustained at least one abdominal injury) from the Crash Injury Research and Engineering Network (CIREN) database. Computed tomography (CT) scans were rendered to visualize fat stranding to determine the presence of a seatbelt sign. 146 positive seatbelt signs were visualized. ASIS level was measured by adjusting the transverse slice of the CT to the visualized ASIS level, which was used to determine seatbelt sign location as superior, on, or inferior to the ASIS. Results Obese occupants had a significantly higher incidence of superior belt placement (52%) vs on-ASIS placement (24%) compared to their normal (27% vs 67%) BMI counterparts (p < 0.001). Notable trends included obese occupants with superior placement having less abdominal organ injury incidence than those with on-ASIS belt placement (42% superior placement vs 55% on-ASIS). In non-obese occupants, there was a higher incidence of abdominal organ injury with superior lap belt placement compared to on-ASIS placement counterparts (Normal BMI: 62% vs 41%, Overweight: 57% vs 43%). Conclusions In CIREN occupants with abdominal injury, those with obesity are more prone to positioning the lap belt superior to the ASIS, though the impact on abdominal injury incidence remains a key point for continued exploration into how occupant BMI affects crash safety and belt design.

Excluding Hollow Viscus Injury for Abdominal Seat Belt Sign Using Computed Tomography

Abdominal seat belt sign (SBS) has historically entailed admission and observation because of the diagnostic limitations of computed tomography (CT) imaging and high rates of hollow viscus injury (HVI). Recent single-institution, observational studies have questioned the utility of this practice. To evaluate whether a negative CT scan can safely predict the absence of HVI in the setting of an abdominal SBS. This prospective, observational cohort study was conducted in 9 level I trauma centers between August 2020 and October 2021 and included adult trauma patients with abdominal SBS. Inclusion in the study required abdominal CT as part of the initial trauma evaluation and before any surgical intervention, if performed. Results of CT scans were considered positive if they revealed any of the following: abdominal wall soft tissue contusion, free fluid, bowel wall thickening, mesenteric stranding, mesenteric hematoma, bowel dilation, pneumatosis, or pneumoperitoneum. Presence of HVI diagnosed at the time of operative intervention. A total of 754 patients with abdominal SBS had an HVI prevalence of 9.2% (n = 69), with only 1 patient with HVI (0.1%) having a negative CT (ie, none of the 8 a priori CT findings). On bivariate analysis comparing patients with and without HVI, there were significant associations between each of the individual CT scan findings and the presence of HVI. The strongest association was found with the presence of free fluid, with a more than 40-fold increase in the likelihood of HVI (odds ratio [OR], 42.68; 95% CI, 20.48-88.94; P < .001). The presence of free fluid also served as the most effective binary classifier for presence of HVI (area under the receiver operator characteristic curve [AUC], 0.87; 95% CI, 0.83-0.91). There was also an association between a negative CT scan and the absence of HVI (OR, 41.09; 95% CI, 9.01-727.69; P < .001; AUC, 0.68; 95% CI, 0.66-0.70). The prevalence of HVI among patients with an abdominal SBS and negative findings on CT is extremely low, if not zero. The practice of admitting and observing all patients with abdominal SBS should be reconsidered when a high-quality CT scan is negative, which may lead to significant resource and cost savings.

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.

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. 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. 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. 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. 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.

Does Abdominal Seat Belt Sign Warrant Admission After a Negative CT Scan? A Cost-Utility Analysis

BackgroundRapid deceleration against a seat belt during a motor vehicle collision (MVC) may result in an abdominal seat belt sign (ASBS), which is associated with a higher risk of hollow viscus injury (HVI). After a negative abdominal CT scan, management of patients with ASBS is variable, but recent evidence suggests emergency department (ED) discharge may be safe. Therefore, we hypothesized that discharge from the ED is cost-effective compared with 23-h observation or hospital admission for patients with ASBS and a negative CT. MethodsA cost-utility model was developed for an evaluable patient with ASBS and negative CT scan using TreeAge software. ED discharge was compared with 23-h observation and admission. Analysis was from a health care–based third-party payer perspective. Quality-adjusted life years (QALYs) were based on 3-y expected outcomes. Probability and costs were estimated from published literature and the Healthcare Cost and Utilization Project. ResultsIn our base case, ED discharge was the most cost-effective strategy, yielding a cost of $706 with 2.86 QALYs. The average costs of 23-h observation and hospital admission were $2600 and $8,827, respectively, with 2.87 QALYs gained each. The strategy of ED observation becomes cost-effective when the rate of HVI after ED discharge exceeds 2.3%. In a Monte Carlo simulation, ED discharge was the optimal strategy in 91% of 1000 trials of the model. ConclusionsED discharge is a cost-effective strategy for evaluable patients with ASBS and a negative abdominal CT and remains so when the risk of HVI after ED discharge is higher than currently assumed.

The abdominal seatbelt sign.

The abdominal seatbelt sign.

Complicated Abdominal Seat Belt Injuries in Children

Background: The proper use of security accessories in cars has resulted in the reduction of morbidity and mortality both in adults and children. Improper use of abdominal seat belt is associated in some cases with severe abdominal injuries. Objectives: Investigation of the treatment outcomes of children who suffered complicated abdominal seat belt injuries between 1998 and 2013. Methods: We present five cases of children aged 6-14 years, who suffered complicated abdominal injuries due to improper use of the seat belt. Abdominal injuries included injuries to the liver, spleen, small bowel (duodenum, jejunum, and ileum), colon and aorta, mesenterial bleeding, retroperitoneal bleeding, bowel obstruction and pelvic fractures. Results: Three children were operated on within a few hours of admission due to peritoneal irritation, hemodynamic instability after fluid resuscitation, bowel injuries including perforation and bowel ischemia. Two children who were hemodynamically stable, were operated on after few days. One of them had a diagnosis of aortic injury and the other, bowel obstruction. The first child was treated in two stages: i. repair of duodenal rupture, and ii. repair of the aortic injury by using interposition Gore-Tex graft. For the child with bowel obstruction, segmental resection and primary anastomosis were performed. The operation and postoperative periods for all children were uneventful, and all five children are healthy today. Conclusion: 1) The abdominal seat belt should always be used in conjunction with the chest seat belt. 2) An abdominal seat belt sign should always raise the possibility of complicated abdominal injuries. 3) Gastrointestinal tract injuries are common in this setting. 4) Aortic injury is rare; however, it can easily be missed initially. 5) Abdominal aortic trauma is associated with duodenal injuries in almost all cases.

The use of computed tomography imaging for abdominal seatbelt sign: A single-center, prospective evaluation

IntroductionGuidelines surrounding abdominal seat belt sign (SBS) were made prior to the use of modern computed tomography (CT) imaging. We sought to prospectively determine whether a negative CT scan is associated with the absence of hollow viscus injury (HVI), and we hypothesized that trauma patients with an abdominal SBS without CT imaging findings would not have a hollow viscus injury (HVI). MethodsA prospective cohort of patients with SBS was compiled over one year. Subjects were divided into those with and without HVI. Covariate distributions were summarized by group. Bivariate tests and logistic regression were used to investigate associations between covariates and HVI. ResultsOf 220 patients with SBS, the incidence of HVI was 7% (n = 15). Radiographic findings were strongly associated with HVI and no patients with a negative CT scan had HVI. Free fluid was seen in 80% (12) of patients with HVI, whereas it was found in only 11% (23) without injury. A composite variable for negative CT scan was found to be associated with the absence of HVI: (Fisher's exact 1-tailed p, doubled = 0.014). ConclusionIn this study, the incidence of HVI with SBS is lower than previously reported, and no patients with negative CT imaging required an operation for HVI—suggesting there is a population of patients with SBS who could be discharged from the emergency room. A prospective multicenter study is needed to confirm these findings.

Position of the abdominal seat belt sign and its predictive utility for abdominal trauma.

In a motor vehicle crash, compressive forces from the lap component of the seat belt may produce an abdominal abrasion/contusion known as the 'seat belt sign', and is associated with abdominal and lumbar injuries. Previous research has not taken into account the position of this sign in relation to the anterior superior iliac spine (ASIS). Our aim was to demonstrate an association between the seat belt sign position in relation to ASIS and the presence of abdominal/lumbar injury. A mixed prospective and retrospective observational study of patients involved in a motor vehicle crash was conducted. The presence of a seat belt sign was recorded as above ASIS, at/below ASIS, or none. Injury data were extracted from discharge summaries, radiology reports and operation reports. Proportions of patients with injuries were compared across the three groups. Four hundred and sixty-four participants were enrolled. For participants with a seat belt sign above ASIS, compared to those with no seat belt sign, the positive likelihood ratio for a seat belt related injury was 4.2 (95% CI 2.6-6.8). When the seat belt sign was at/below the level of ASIS the positive likelihood ratio was 1.5 (95% CI 0.4-5.7). The seat belt sign is associated with abdominal and lumbar injury; however, the location is important. This association is strong when the seat belt sign is above ASIS, but when the sign is at/below the ASIS the injury rate is similar to participants with no seat belt sign. Routine imaging of the abdomen may be appropriate only for those with a seat belt sign above ASIS.

A negative computed tomography may be sufficient to safely discharge patients with abdominal seatbelt sign from the emergency department: A case series analysis: Barmparas G, Patel DC, Linaval NT, et al. J Trauma Acute Care Surg. 2018;46(6):900-907

A negative computed tomography may be sufficient to safely discharge patients with abdominal seatbelt sign from the emergency department: A case series analysis: Barmparas G, Patel DC, Linaval NT, et al. J Trauma Acute Care Surg. 2018;46(6):900-907

A negative computed tomography may be sufficient to safely discharge patients with abdominal seatbelt sign from the emergency department: A case series analysis.

The presence of an abdominal seatbelt sign (ASBS) following a motor vehicle collision (MVC) is associated with a high risk for occult intra-abdominal injury, prompting imaging studies and a prolonged period of clinical observation. The aim of this study was to determine how a negative computed tomography (CT) of the abdomen/pelvis (A/P) can serve in the safe disposition of these patients. Our hypothesis was that in the setting of a negative CT, the presence of occult intra-abdominal injuries requiring a delayed intervention is extremely unlikely. The medical charts of patients admitted from January 2014 to December 2016 to a Level I trauma center following an MVC were reviewed for a documentation of an ASBS. Patients who did not have a CT A/P upon admission were excluded. The CT A/P of the remaining patients were then classified as negative if there were no findings of acute vascular, visceral or bony injury or positive if any of these findings was present. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CT A/P for the presence of an intra-abdominal injury were calculated. Over the 3-year study period, 1,108 patients were admitted after an MVC. Of those, 196 (17.7%) had an ASBS upon presentation and 183 (93.4%) of 196 underwent a CT A/P. A total of 114 (62.3%) of 183 had a negative CT A/P. These patients remained hospitalized for a median of 2 (1-35) days with none (0.0%) requiring a delayed laparotomy. The sensitivity of CT A/P in identifying patients requiring an exploratory laparotomy was 100.0%, specificity was 67.9%, NPV was 100.0%, and PPV was 21.7%. The negative likelihood ratio was 0.00. For patients with an ASBS following an MVC, a negative CT A/P may be sufficient for safe discharge from the emergency department without any need for additional clinical observation. Therapuetic, level IV.

Discussion of: “Redefining the abdominal seatbelt sign: Enhanced CT imaging metrics improve injury prediction”

Discussion of: “Redefining the abdominal seatbelt sign: Enhanced CT imaging metrics improve injury prediction”

Redefining the abdominal seatbelt sign: Enhanced CT imaging metrics improve injury prediction

IntroductionThe abdominal seatbelt sign (ASBS) has an established association with abdominal injury, yet its definition remains ill-defined. We hypothesize specific imaging characteristics associated with the ASBS such as location above the pelvic brim and depth of abdominal wall contusion would better predict underlying injury and need for operative intervention. MethodsWe performed a retrospective chart review of subjects suffering from restrained motor vehicle collisions (MVC) evaluated at a level one trauma facility from 2010 to 2015. CT imaging was reviewed for the presence of a transverse abdominal wall contusion consistent with lap belt use. Contusion location was determined in relation to the anterior superior iliac spine (ASIS). Abdominal wall thickness as well as contusion depth were measured at the contusion level and an abdominal seatbelt sign depth index (ASBSI) was calculated. ResultsSample size for the cohort was 551 subjects. Operative need was 19.73% in those with ASBS on CT (CT ASBS) above the ASIS and 4.05% (p-value < 0.01) in those with only clinical evidence of ASBS (CL ASBS). CT ASBS above the ASIS was associated with higher incidence of intra-abdominal injuries (31.97% vs 16.45%; p = 0.01) and a higher rate of abdominal operations (19.73% vs. 7.59%; p < 0.01) compared to below the ASIS. In contrast, CT ASBS below the ASIS was associated with a higher incidence of pelvic fractures (17.72% vs. 8.16%; p = 0.01) with fractures being an independent risk factor for abdominal injury requiring intervention. Logistic regression analyses and receiver-operator characteristic curves demonstrated ASBSI was significantly associated with abdominal injury requiring operative intervention. ConclusionCharacteristics of abdominal wall injury on imaging such as location and contusion depth (ASBSI) are better predictors of abdominal operative need than standard clinical measures. This analysis substantiates a novel diagnostic tool which may have the potential to facilitate clinical diagnosis and management decisions in patients with abdominal seatbelt sign.

Association between the seat belt sign and intra-abdominal injuries in children with blunt torso trauma in motor vehicle collisions.

The objective was to determine the association between the abdominal seat belt sign and intra-abdominal injuries (IAIs) in children presenting to emergency departments with blunt torso trauma after motor vehicle collisions (MVCs). This was a planned subgroup analysis of prospective data from a multicenter cohort study of children with blunt torso trauma after MVCs. Patient history and physical examination findings were documented before abdominal computed tomography (CT) or laparotomy. Seat belt sign was defined as a continuous area of erythema, ecchymosis, or abrasion across the abdomen secondary to a seat belt restraint. The relative risk (RR) of IAI with 95% confidence intervals (CIs) was calculated for children with seat belt signs compared to those without. The risk of IAI in those patients with seat belt sign who were without abdominal pain or tenderness, and with Glasgow Coma Scale (GCS) scores of 14 or 15, was also calculated. A total of 3,740 children with seat belt sign documentation after blunt torso trauma in MVCs were enrolled; 585 (16%) had seat belt signs. Among the 1,864 children undergoing definitive abdominal testing (CT, laparotomy/laparoscopy, or autopsy), IAIs were more common in patients with seat belt signs than those without (19% vs. 12%; RR = 1.6, 95% CI = 1.3 to 2.1). This difference was primarily due to a greater risk of gastrointestinal injuries (hollow viscous or associated mesentery) in those with seat belt signs (11% vs. 1%; RR = 9.4, 95% CI = 5.4 to 16.4). IAI was diagnosed in 11 of 194 patients (5.7%; 95% CI = 2.9% to 9.9%) with seat belt signs who did not have initial complaints of abdominal pain or tenderness and had GCS scores of 14 or 15. Patients with seat belt signs after MVCs are at greater risk of IAI than those without seat belt signs, predominately due to gastrointestinal injuries. Although IAIs are less common in alert patients with seat belt signs who do not have initial complaints of abdominal pain or tenderness, the risk of IAI is sufficient that additional evaluation such as observation, laboratory studies, and potentially abdominal CT scanning is generally necessary.

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

Our aim was to determine the diagnostic significance of the association between the abdominal skin bruise from a seat belt and the presence of intraabdominal injury. This was an observational analysis of prospectively collected data on 45 patients who presented with an abdominal seat belt sign to a level 1 trauma center following a motor vehicle accident between July 2004 and December 2007. The patients were evaluated by computed tomography (CT) scans or ultrasonography (FAST), depending on their hemodynamic stability. They were then hospitalized for treatment or observation. Forty-five patients [23 males (51.1%) and 22 females (48.9%)], with a mean age of 32.2 years (range 16-80 years), fulfilled entry criteria and were enrolled. Of these, 44 (97.8%) underwent CT, and one (2.2%) underwent FAST due to hemodynamic instability. two patients (4.4%) had intraabdominal injuries: one required surgery for bowel injury, and the other had a minor liver laceration, which was managed expectantly. Sixteen patients (35.5%) had concomitant injuries. The length of hospital stay ranged from 1-23 days (median 2.2 days). Despite the widely accepted view that patients with an abdominal seat belt sign are more likely to have serious intraabdominal injuries, the results of our investigation showed no such association in a group of hemodynamically stable patients.