ABSTRACT
INTRODUCTION: Sensory overstimulation of autistic patients of all ages during an ED visit can ultimately lead to care escalation, but few studies have evaluated patient perspectives on improving the ED sensory experience across the age continuum. The purpose of this study was to explore patient-centered perspectives on reducing adult and pediatric autistic patients' sensory stimulation during an ED visit. METHODS: We used a qualitative descriptive design to explore how autistic patients experience sensory disruption and recommendations to improve care. Data were analyzed inductively using an overall categorization of 6 senses (visual, auditory, touch, smell, taste, and proprioception). RESULTS: Fourteen adults and 30 caregivers of children provided written responses to open-ended interview questions (n = 44). Participants suggested strategies to minimize the sensory disruption they experienced; however, an overarching recommendation was for clinicians to ask about their or their child's preferences before delivering care or services. CONCLUSION: Because people with autism are more likely to visit an ED than their neurotypical counterparts, ED clinicians should be proficient in "sensory-friendly care." A variety of evidence-based practical strategies and design approaches exist that can be leveraged to reduce the risk of care escalation; however, the most basic may be to prioritize asking patients and their caregivers about their preferences prior to providing care.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Adult , Humans , Child , Autism Spectrum Disorder/therapy , Caregivers , Emergency Service, HospitalABSTRACT
Motor vehicle collisions (MVCs) are a leading cause of acute spinal injuries. Chronic spinal pathologies are common in the population. Thus, determining the incidence of different types of spinal injuries due to MVCs and understanding biomechanical mechanism of these injuries is important for distinguishing acute injuries from chronic degenerative disease. This paper describes methods for determining causation of spinal pathologies from MVCs based on rates of injury and analysis of the biomechanics require to produce these injuries. Rates of spinal injuries in MVCs were determined using two distinct methodologies and interpreted using a focused review of salient biomechanical literature. One methodology used incidence data from the Nationwide Emergency Department Sample and exposure data from the Crash Report Sample System supplemented with a telephone survey to estimate total national exposure to MVC. The other used incidence and exposure data from the Crash Investigation Sampling System. Linking the clinical and biomechanical findings yielded several conclusions. First, spinal injuries caused by an MVC are relatively rare (511 injured occupants per 10,000 exposed to an MVC), which is consistent with the biomechanical forces required to generate injury. Second, spinal injury rates increase as impact severity increases, and fractures are more common in higher-severity exposures. Third, the rate of sprain/strain in the cervical spine is greater than in the lumbar spine. Fourth, spinal disc injuries are extremely rare in MVCs (0.01 occupants per 10,000 exposed) and typically occur with concomitant trauma, which is consistent with the biomechanical findings 1) that disc herniations are fatigue injuries caused by cyclic loading, 2) the disc is almost never the first structure to be injured in impact loading unless it is highly flexed and compressed, and 3) that most crashes involve predominantly tensile loading in the spine, which does not cause isolated disc herniations. These biomechanical findings illustrate that determining causation when an MVC occupant presents with disc pathology must be based on the specifics of that presentation and the crash circumstances and, more broadly, that any causation determination must be informed by competent biomechanical analysis.
Subject(s)
Fractures, Bone , Intervertebral Disc Displacement , Spinal Injuries , Humans , Accidents, Traffic , Intervertebral Disc Displacement/complications , Spinal Injuries/epidemiology , Spinal Injuries/etiology , Motor VehiclesABSTRACT
OBJECTIVE: The Abbreviated Injury Scale (AIS) is an anatomic-based injury coding system that strives to provide sufficient detail to differentiate unique injuries for the purposes of research and quality assurance, while limiting the total number of codes to facilitate efficient use. It has been shown that a substantial portion of codes are unused in automotive-trauma specific databases. The goal of this study was to determine the percentage of codes utilized in a nationwide trauma registry that includes multiple mechanisms of injury. Secondary objectives were to examine unused codes and determine the number of codes that were most frequently utilized. METHODS: Data were obtained from the National Trauma Data Bank (NTDB) years 2016 and 2017. All injury data were recorded using AIS version 2005 update 2008 (AIS08), which contains 1,999 distinct injury codes. The percentage of the total number of AIS08 codes used in NTDB were determined for each year individually and the combination of both years. The unused codes were then examined manually to identify common characteristics. Finally, the number of codes that provided 95% coverage of all recorded injuries was calculated. RESULTS: There were 6,661,110 injuries recorded for 1,953,775 patients in NTDB over the two-year period. A small percentage of codes had an incorrect severity level (0.07%) or an incorrect injury code (0.0002%). There were 1,987 (99.4% of the entire AIS dictionary) unique AIS08 codes utilized in each year, with the unused codes varying between years. The unused codes tended to involve specific nerves, dural sinuses, or severe, bilateral injuries. During the combined two-year period, 1,996 (99.8% of the entire dictionary) unique AIS08 codes were used. Although almost every code was used at least once, 95% of the injuries in NTDB used only the 631 (31.6%) most frequent AIS08 codes. CONCLUSIONS: In contrast to automotive specific databases, nearly all the AIS08 codes are used each year in the NTDB. Over a two-year period, only three AIS08 injuries were unused. However, less than a third of AIS08 codes encompass 95% of the injuries. Further research is necessary to determine if common codes should be separated into multiple distinct codes to enhance discriminatory ability of AIS.
Subject(s)
Accidents, Traffic , Wounds and Injuries , Humans , Abbreviated Injury Scale , Registries , Databases, Factual , International Classification of Diseases , Injury Severity Score , Wounds and Injuries/epidemiologyABSTRACT
Traumatic brain injuries (TBI) are a substantial societal burden. The development of better technologies and systems to prevent and/or mitigate the severity of brain injury requires an improved understanding of the mechanisms of brain injury, and more specifically, how head impact exposure relates to brain deformation. Biomechanical investigations have used computational models to identify these relations, but more experimental brain deformation data are needed to validate these models and support their conclusions. The objective of this study was to generate a dataset describing in situ human brain motion under rotational loading at impact conditions considered injurious. Six head-neck human post-mortem specimens, unembalmed and never frozen, were instrumented with 24 sonomicrometry crystals embedded throughout the parenchyma that can directly measure dynamic brain motion. Dynamic brain displacement, relative to the skull, was measured for each specimen with four loading severities in the three directions of controlled rotation, for a total of 12 tests per specimen. All testing was completed 42-72 h post-mortem for each specimen. The final dataset contains approximately 5,000 individual point displacement time-histories that can be used to validate computational brain models. Brain motion was direction-dependent, with axial rotation resulting in the largest magnitude of displacement. Displacements were largest in the mid-cerebrum, and the inferior regions of the brain-the cerebellum and brainstem-experienced relatively lower peak displacements. Brain motion was also found to be positively correlated to peak angular velocity, and negatively correlated with angular velocity duration, a finding that has implications related to brain injury risk-assessment methods. This dataset of dynamic human brain motion will form the foundation for the continued development and refinement of computational models of the human brain for predicting TBI.
Subject(s)
Biomechanical Phenomena/physiology , Brain/diagnostic imaging , Brain/physiology , Head Movements/physiology , Rotation , Tomography, X-Ray Computed/methods , Aged , Aged, 80 and over , Female , Head/diagnostic imaging , Head/physiology , Humans , Male , Middle Aged , Tomography, X-Ray Computed/instrumentationABSTRACT
Dual Sequential Defibrillation (DSD) has shown promise in the management of refractory ventricular fibrillation (RVF). In the recent past, there have been a number of reports on the topic with varying results. Some studies have concluded that DSD provides no benefit over standard defibrillation therapy of RVF in terms of survival and neurological outcome. In fact, termination of RVF and achieving return of spontaneous circulation (ROSC) are achieved quite frequently in patients with DSD. Unfortunately, DSD has been utilized very late in the course of resuscitation, likely masking a great deal of its potential benefit. Interventions at this later phase of resuscitation are much less likely to produce a beneficial outcome, regardless of their ability to impact the course of events. It is suggested that earlier use of DSD can potentially improve ROSC, ultimate survival, and neurological outcome. After a review of the existing literature on the topic, we will propose that DSD be considered for use at a much earlier time in the resuscitation of patients with RVF. In addition to the consideration of its use in resuscitation, clinicians and device manufacturers must also address the impact on the two defibrillation devices employed in DSD due to the potential for damage and resultant defibrillator dysfunction.
Subject(s)
Electric Countershock/methods , Out-of-Hospital Cardiac Arrest/therapy , Ventricular Fibrillation/therapy , Cardiopulmonary Resuscitation/methods , Defibrillators , Emergency Medical Services/methods , Humans , Treatment OutcomeABSTRACT
[This corrects the article on p. 1108 in vol. 18, PMID: 29085544.].
ABSTRACT
OBJECTIVE: Previous work has shown that the lap belt moves superior and forward compared to the bony pelvis as body mass index (BMI) increases. The goal of this project was to determine whether the location of lap belt loading is related to BMI for occupants who sustained real-world motor vehicle collisions (MVCs). METHODS: A national MVC database was queried for vehicle occupants over a 10-year period (2003-2012) who were at least 16 years old, restrained by a 3-point seat belt, sitting in the front row, and involved in a front-end collision with a change in velocity of at least 56 km/h. Cases were excluded if there was not an available computed tomography (CT) scan of the abdomen. CT scans were then analyzed using adipose enhancement of 3-dimensional reconstructions. Scans were assessed for the presence a radiographic seat belt sign (rSBS), or subcutaneous fat stranding due to seat belt loading. In scans in which the rSBS was present, anterior and superior displacement of rSBS from the anterior-superior iliac spine (ASIS) was measured bilaterally. This displacement was correlated with BMI and injury severity. RESULTS: The inclusion and exclusion criteria yielded 151 cases for analysis. An rSBS could definitively be identified in 55 cases. Cases in which occupants were older and had higher BMI were more likely to display an rSBS. There was a correlation between increasing BMI and anterior rSBS displacement (P <.01 and P <.01, right and left, respectively). There was no significant correlation between BMI and superior displacement of the rSBS (P =.46 and P =.33, right and left, respectively). When the data were examined in terms of relating increasing superior displacement of the lap belt with Injury Severity Scale (P =.34) and maximum Abbreviated Injury Score (AIS) injury severity (P =.63), there was also no significant correlation. CONCLUSION: The results from this study demonstrated that anterior displacement of the radiographic seat belt sign but not superior displacement increased with higher BMI. These results suggest that obesity may worsen horizontal position but not the vertical position of the lap belt loading during real-world frontal MVCs.
Subject(s)
Accidents, Traffic/statistics & numerical data , Obesity , Seat Belts , Weight-Bearing , Adolescent , Adult , Aged , Aged, 80 and over , Body Mass Index , Databases, Factual , Equipment Design , Female , Humans , Injury Severity Score , Male , Middle Aged , Young AdultABSTRACT
INTRODUCTION: There are established and validated clinical decision tools for cervical spine clearance. Almost all the rules include spinal tenderness on exam as an indication for imaging. Our goal was to apply GLASS, a previously derived clinical decision tool for cervical spine clearance, to thoracolumbar injuries. GLass intact Assures Safe Spine (GLASS) is a simple, objective method to evaluate those patients involved in motor vehicle collisions and determine which are at low risk for thoracolumbar injuries. METHODS: We performed a retrospective cohort study using the National Accident Sampling System-Crashworthiness Data System (NASS-CDS) over an 11-year period (1998-2008). Sampled occupant cases selected in this study included patients age 16-60 who were belt-restrained, front- seat occupants involved in a crash with no airbag deployment, and no glass damage prior to the crash. RESULTS: We evaluated 14,191 occupants involved in motor vehicle collisions in this analysis. GLASS had a sensitivity of 94.4% (95% CI [86.3-98.4%]), specificity of 54.1% (95% CI [53.2-54.9%]), and negative predictive value of 99.9% (95% CI [99.8-99.9%]) for thoracic injuries, and a sensitivity of 90.3% (95% CI [82.8-95.2%]), specificity of 54.2% (95% CI [53.3-54.9%]), and negative predictive value of 99.9% (95% CI [99.7-99.9%]) for lumbar injuries. CONCLUSION: The GLASS rule represents the possibility of a novel, more-objective thoracolumbar spine clearance tool. Prospective evaluation would be required to further evaluate the validity of this clinical decision rule.
Subject(s)
Accidents, Traffic , Decision Support Systems, Clinical , Lumbar Vertebrae/injuries , Spinal Fractures/diagnosis , Thoracic Injuries/diagnosis , Adolescent , Adult , Female , Humans , Male , Middle Aged , Retrospective Studies , Spinal Fractures/etiology , Thoracic Injuries/etiology , Young AdultABSTRACT
OBJECTIVES: The 2 objectives of this study are to (1) examine the rib and sternal fractures sustained by small stature elderly females in simulated frontal crashes and (2) determine how the findings are characterized by prior knowledge and field data. METHODS: A test series was conducted to evaluate the response of 5 elderly (average age 76 years) female postmortem human subjects (PMHS), similar in mass and size to a 5th percentile female, in 30 km/h frontal sled tests. The subjects were restrained on a rigid planar seat by bilateral rigid knee bolsters, pelvic blocks, and a custom force-limited 3-point shoulder and lap belt. Posttest subject injury assessment included identifying rib cage fractures by means of a radiologist read of a posttest computed tomography (CT) and an autopsy. The data from a motion capture camera system were processed to provide chest deflection, defined as the movement of the sternum relative to the spine at the level of T8. A complementary field data investigation involved querying the NASS-CDS database over the years 1997-2012. The targeted cases involved belted front seat small female passenger vehicle occupants over 40 years old who were injured in 25 to 35 km/h delta-V frontal crashes (11 to 1 o'clock). RESULTS: Peak upper shoulder belt tension averaged 1,970 N (SD = 140 N) in the sled tests. For all subjects, the peak x-axis deflection was recorded at the sternum with an average of -44.5 mm or 25% of chest depth. The thoracic injury severity based on the number and distribution of rib fractures yielded 4 subjects coded as Abbreviated Injury Scale (AIS) 3 (serious) and one as AIS 5 (critical). The NASS-CDS field data investigation of small females identified 205 occupants who met the search criteria. Rib fractures were reported for 2.7% of the female occupants. CONCLUSIONS: The small elderly test subjects sustained a higher number of rib cage fractures than expected in what was intended to be a minimally injurious frontal crash test condition. Neither field studies nor prior laboratory frontal sled tests conducted with 50th percentile male PMHS predicted the injury severity observed. Although this was a limited study, the results justify further exploration of the risk of rib cage injury for small elderly female occupants.
Subject(s)
Accidents, Traffic , Fractures, Bone/etiology , Rib Cage/injuries , Sternum/injuries , Abbreviated Injury Scale , Aged , Aged, 80 and over , Biomechanical Phenomena , Cadaver , Databases, Factual , Female , Fractures, Bone/diagnostic imaging , Fractures, Bone/physiopathology , Humans , Middle Aged , Osteoporotic Fractures/diagnostic imaging , Osteoporotic Fractures/etiology , Osteoporotic Fractures/physiopathology , Rib Cage/diagnostic imaging , Rib Fractures/diagnostic imaging , Rib Fractures/etiology , Rib Fractures/physiopathology , Seat Belts , Sternum/diagnostic imaging , Sternum/physiopathology , Tomography, X-Ray ComputedABSTRACT
IMPORTANCE: The practice of facial trauma surgery would benefit from a useful quantitative scale that measures the extent of injury. OBJECTIVE: To develop a facial trauma scale that incorporates only reducible fractures and is able to be reliably communicated to health care professionals. DESIGN AND SETTING: A cadaveric tissue study was conducted from October 1 to 3, 2014. Ten cadaveric heads were subjected to various degrees of facial trauma by dropping a fixed mass onto each head. The heads were then imaged with fine-cut computed tomography. A Bony Facial Trauma Scale (BFTS) for grading facial trauma was developed based only on clinically relevant (reducible) fractures. The traumatized cadaveric heads were then scored using this scale as well as 3 existing scoring systems. Regression analysis was used to determine correlation between degree of incursion of the fixed mass on the cadaveric heads and trauma severity as rated by the scoring systems. Statistical analysis was performed to determine correlation of the scores obtained using the BFTS with those of the 3 existing scoring systems. Scores obtained using the BFTS were not correlated with dentition (95% CI, -0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (95% CI, -0.068 to 0.944; P = .08). MAIN OUTCOME MEASURES: Facial trauma scores. RESULTS: Among all 10 cadaveric specimens (9 male donors and 1 female donor; age range, 41-87 years; mean age, 57.2 years), the facial trauma scores obtained using the BFTS correlated with depth of penetration of the mass into the face (odds ratio, 4.071; 95% CI, 1.676-6.448) P = .007) when controlling for presence of dentition and age. The BFTS scores also correlated with scores obtained using 3 existing facial trauma models (Facial Fracture Severity Scale, rs = 0.920; Craniofacial Disruption Score, rs = 0.945; and ZS Score, rs = 0.902; P < .001 for all 3 models). In addition, the BFTS was found to have excellent interrater reliability (0.908; P = .001), which was similar to the interrater reliability of the other 3 tested trauma scales. Scores obtained using the BFTS were not correlated with dentition (odds ratio, .482; 95% CI, -0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (odds ratio, .436; 95% CI, -0.068 to 0.944; P = .08). CONCLUSIONS AND RELEVANCE: Facial trauma severity as measured by the BFTS correlated with depth of penetration of the fixed mass into the face. In this study, the BFTS was clinically relevant, had high fidelity in communicating the fractures sustained in facial trauma, and correlated well with previously validated models. LEVEL OF EVIDENCE: NA.
Subject(s)
Bone Plates , Facial Bones/injuries , Facial Injuries/classification , Fracture Fixation, Internal , Trauma Severity Indices , Adult , Aged , Aged, 80 and over , Cadaver , Female , Humans , Male , Middle Aged , Observer Variation , Reproducibility of ResultsABSTRACT
This study was conducted to identify the event characteristics of mass gatherings that predict patient presentation rates held in a southeastern US university community. We conducted a retrospective review of all event-based emergency medical services (EMS) records from mass gathering patient presentations over an approximate 23 month period, from October 24, 2009 to August 27, 2011. All patrons seen by EMS were included. Event characteristics included: crowd size, venue percentage filled seating, venue location (inside/outside), venue boundaries (bounded/unbounded), presence of free water (i.e., without cost), presence of alcohol, average heat index, presence of climate control (i.e., air conditioning), and event category (football, concerts, public exhibitions, non-football athletic events). We identified 79 mass gathering events, for a total of 670 patient presentations. The cumulative patron attendance was 917,307 persons. The patient presentation rate (PPR) for each event was calculated as the number of patient presentations per 10,000 patrons in attendance. Overdispersed Poisson regression was used to relate this rate to the event characteristics while controlling for crowd size. In univariate analyses, increased rates of patient presentations were strongly associated with outside venues [rate ratio (RR) = 3.002, p < 0.001], unbounded venues (RR = 2.839, p = 0.001), absence of free water (RR = 1.708, p = 0.036), absence of climate control (RR = 3.028, p < 0.001), and a higher heat index (RR = 1.211 per 10-unit heat index increase, p = 0.003). The presence of alcohol was not significantly associated with the PPR. Football events had the highest PPR, followed sequentially by public exhibitions, concerts, and non-football athletic events. In multivariate models, the strong predictors from the univariate analyses retained their predictive significance for the PPR, together with heat index and percent seating. In the setting of mass event medical care, we note that several factors are strongly associated with an increased patient census, including outside (external) or unbounded venues, the absence of fee water (i.e., without cost), no climate control, percent (occupied) seating, and increasing heat index. Although the presence of alcohol is noted to increase patient needs, it does not do so significantly. Regarding event type, collegiate football games have the highest patient census among the range of other events studied. These findings should be considered during the process of EMS resource planning for mass gatherings.
Subject(s)
Emergency Service, Hospital/statistics & numerical data , Mass Behavior , Anniversaries and Special Events , Crowding , Emergency Service, Hospital/trends , Humans , Poisson Distribution , Retrospective Studies , Southeastern United StatesABSTRACT
Older adults are at greater risk than younger adults for life-threatening injury after motor vehicle collision (MVC). Among those with life-threatening injury, older adults are also at greater risk of not being transported by emergency medical services (EMS) to an emergency department. Despite the greater risk of serious injury and non-transportation among older adults, little is known about the relationship between patient age and EMS transportation rates for individuals experiencing MVC. We describe transport rates across the age-span for adults seen by EMS after experiencing MVC using data reported to the North Carolina Department of Motor Vehicles between 2008 and 2011. Of all adults aged 18 years and older experiencing MVC and seen by EMS (n=484,310), 36.3% (n=175,768) were transported to an emergency department. Rates of transport for individuals seen by EMS after MVC increased only a small amount with increasing patient age. After adjusting for potential confounders of the relationship between patient age and the decision to transport (patient gender, patient race, air bag deployment, patient trapped or ejected, and injury severity), transport rates were: age 18-64=36.0% (95% confidence interval [CI], 35.9-36.2%); age 65-74=36.6% (95% CI, 36.0-37.1%); age 75-84=37.3% (95% CI, 36.5-38.1%), and age 85-94=38.2% (95% CI, 36.7-39.8%). In North Carolina between 2008 and 2011, the transportation rate was only slightly higher for older adults than for younger adults, and most older adults experiencing MVC and seen by EMS were not transported to the emergency department. These findings have implications for efforts to improve the sensitivity of criteria used by EMS to determine the need for transport for older adults experiencing MVC.
Subject(s)
Accidents, Traffic , Ambulances/statistics & numerical data , Emergency Medical Services/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , Wounds and Injuries , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Female , Health Services Needs and Demand , Humans , Logistic Models , Male , Middle Aged , North Carolina , Transportation of Patients/statistics & numerical data , Triage , Young AdultABSTRACT
OBJECTIVES: We studied a population of individuals who experienced an acute coronary syndrome (ACS) event while traveling abroad and required nonurgent commercial air travel to the home region. METHODS: This retrospective study gathered data from 288 patients enrolled in a travel-based medical assistance program. Interventions, complications, and travel home were assessed for trends. Descriptive and comparison statistical analyses were performed. RESULTS: Two hundred eighty-eight patients were identified and entered into the review. Of the patients in this study, 77.1% were male with an average age of 67.7 years. One hundred sixteen (40.3%) patients were diagnosed with unstable angina pectoris (USAP), whereas the remaining 172 (59.7%) patients experienced acute myocardial infarction (AMI). Regarding inpatient complications during the initial admission, 121 (42.0%) patients experienced 1 or more adverse event. The average number of days after an ACS event that a patient began to travel home was 10.5 days for the entire patient population (USAP patients = 8.8 days, AMI patients = 11.8 days). Two hundred twenty (76.4%) patients traveled with a medical escort, and 48 (16.7%) patients received supplemental oxygen during air travel. Four (1.4%) in-flight adverse events occurred in the following ACS diagnostic groups: 2 in the complicated AMI group, 1 in the uncomplicated USAP group, and 1 in the uncomplicated AMI group. No in-flight deaths occurred. Nine (3.1%) deaths were noted within 2 weeks after returning to the home region. The deaths after returning to the home region occurred in the following ACS diagnostic groups: 2 in the complicated USAP group, 1 in the uncomplicated USAP group, and 6 in the complicated AMI group. None of the patients who experienced in-flight events died after returning to their home region. CONCLUSIONS: Upon discharge, the vast majority of ACS patients who travel to their home region via commercial air do not experience adverse events in-flight; when such adverse events occur in-flight, these events do not result in a poor outcome. No in-flight deaths occurred; death occurred in a minority of patients after returning to their home region, particularly in the complicated USAP and AMI groups, who were planned readmissions to the hospital.
Subject(s)
Acute Coronary Syndrome/therapy , Aircraft , Travel , Acute Coronary Syndrome/complications , Acute Coronary Syndrome/epidemiology , Aged , Angina, Unstable/complications , Angina, Unstable/epidemiology , Angina, Unstable/therapy , Female , Humans , Male , Myocardial Infarction/complications , Myocardial Infarction/epidemiology , Myocardial Infarction/therapy , Retrospective Studies , Transportation of Patients/statistics & numerical data , Travel/statistics & numerical data , Travel MedicineABSTRACT
OBJECTIVE: The objective of this study is to assess the response of postmortem human subjects (PMHS) to a large-volume side air bag in a fully instrumented and well-controlled side impact test condition. METHODS: Three adult male PMHS were subjected to right-side pure lateral impacts. Each stationary seated subject was struck at 4.3 ± 0.1 m/s by a rigid wall installed on a 1700-kg rail-mounted sled. Each subject was held stationary by a system of tethers until immediately prior to being impacted by the moving wall. A large side air bag was mounted to the wall and deployed so that it was fully inflated at the time it contacted the subject's right side. The load wall consisted of an adjustable matrix of 15 individual plates, each supported by a 5-axis load cell that recorded the interaction between the subject and impacting wall. Two-dimensional (external) torso deformation was provided by a chest band that encircled the torso at the level of the sixth rib laterally. Triaxial acceleration was measured at the head, spine, and sacrum via 3 orthogonal accelerometers mounted to the same bone-mounted hardware that held the marker clusters used for kinematic analysis. RESULTS: Peak pelvic load normal to the wall averaged 6.8 kN, which was over 5 times that recorded for the shoulder (1.3 kN) and the thorax (1.2 kN). Lateral chest deflection ranged from 9 to 21 mm. Two of the 3 subjects sustained 2 and 9 fractures, respectively. CONCLUSIONS: Two of the 3 PMHS sustained rib fractures despite low levels of thorax deflection. We attribute this finding to individual variability in subject injury tolerance. Other response parameters exhibited lower levels of variability and characterize PMHS response to a potentially beneficial side impact countermeasure. Supplemental materials are available for this article. Go to the publisher's online edition of Traffic Injury Prevention to view the supplemental file.
Subject(s)
Accidents, Traffic/statistics & numerical data , Air Bags , Rib Fractures/etiology , Thorax/physiology , Adult , Biomechanical Phenomena , Cadaver , Humans , MaleABSTRACT
The objective of the current study was to characterize the whole-body kinematic response of restrained PMHS in controlled laboratory rollover tests. A dynamic rollover test system (DRoTS) and a parametric vehicle buck were used to conduct 36 rollover tests on four adult male PMHS with varied test conditions to study occupant kinematics during the rollover event. The DRoTS was used to drop/catch and rotate the test buck, which replicated the occupant compartment of a typical mid-sized SUV, around its center of gravity without roof-to-ground contact. The studied test conditions included a quasi-static inversion (4 tests), an inverted drop and catch that produced a 3 g vertical deceleration (4 tests), a pure dynamic roll at 360 degrees/second (11 tests), and a roll with a superimposed drop and catch produced vertical deceleration (17 tests). Each PMHS was restrained with a three-point belt and was tested in both leading-side and trailing-side front-row seating positions. Whole-body kinematics were measured using a 3D motion capture system that quantified occupant displacement relative to the vehicle buck for the X-axis (longitudinal), Y-axis (lateral), and Z-axis (vertical) directions. Additionally the spine was divided into five segments to describe intrasegmental kinematics of the spine, including segment rotations as well as spinal extension and compression. The reported data represent the most complete set of kinematic response targets for a restrained occupant in a variety of dynamic rollover conditions, and are immediately useful for efforts to evaluate and improve existing ATDs and computational models for use in the rollover crash environment.
Subject(s)
Accidents, Traffic , Automobiles , Wounds and Injuries , Adult , Biomechanical Phenomena/physiology , Computer Simulation , Humans , Male , Models, Biological , Risk Assessment/methods , Seat Belts , Stress, Physiological , Trauma Severity Indices , Wounds and Injuries/etiology , Wounds and Injuries/mortality , Wounds and Injuries/physiopathology , Wounds and Injuries/prevention & controlSubject(s)
Accidents, Traffic/mortality , Adolescent , Adult , Age Factors , Child , Child, Preschool , Humans , Life Expectancy , United States/epidemiology , Young AdultABSTRACT
BACKGROUND: Selective cervical spine immobilization performed by Emergency Medical Services (EMS) is being utilized with increasing frequency. These protocols, although very sensitive, still include subjective data such as "mild cervical discomfort." The aim of this study is to create an objective clinical decision rule that would enhance the selective approach for cervical spine immobilization in patients aged 16-60 years. STUDY OBJECTIVE: It is hypothesized that, in a motor vehicle crash, the integrity of the involved vehicle's glass window and airbag status is an excellent objective measure for the amount of energy a vehicle occupant has experienced during the crash. GLass intact Assures Safe Spine (GLASS) is an easy and objective method for evaluation of the need for prehospital cervical spine immobilization. METHODS: A retrospective cohort study was performed with sample motor vehicle crash cases to evaluate the performance of the GLASS rule. The National Accident Sampling System-Crashworthiness Data System (NASS-CDS) was utilized to investigate tow-away motor vehicle crashes, including their glass damage characteristics and occupant injury outcomes, over an 11-year period (1998-2008). Sample occupant cases selected for this study were patients aged 16-60 years, who were belt-restrained front seat occupants involved in a crash with no airbag deployment, and no glass damage before the crash. RESULTS: A total of 14,191 occupants involved in motor vehicle crashes were evaluated in this analysis. The results showed that the sensitivity of the GLASS rule was 95.20% (95% confidence interval [CI] 91.45-98.95%), the specificity was 54.27% (95% CI 53.44-55.09%), and the negative predictive value was 99.92% (95% CI 99.86-99.98%). CONCLUSION: The GLASS rule presents the possibility of a novel, more objective tool for cervical spine clearance. Prospective evaluation is required to further evaluate the validity of this clinical decision rule.
Subject(s)
Accidents, Traffic , Cervical Vertebrae/injuries , Clinical Protocols , Decision Support Systems, Clinical , Immobilization , Spinal Injuries/therapy , Adolescent , Adult , Female , Humans , Immobilization/statistics & numerical data , Male , Middle Aged , Sensitivity and Specificity , Young AdultABSTRACT
In far-side impacts, head contact with interior components is a key injury mechanism. Restraint characteristics have a pronounced influence on head motion and injury risk. This study performed a parametric examination of restraint, positioning, and collision factors affecting shoulder belt retention and occupant kinematics in far-side lateral and oblique sled tests with post mortem human subjects (PMHS). Seven PMHS were subjected to repeated tests varying the D-ring position, arm position, pelvis restraint, pre-tensioning, and impact severity. Each PMHS was subjected to four low-severity tests (6.6 g sled acceleration pulse) in which the restraint or position parameters were varied and then a single higher-severity test (14 g) with a chosen restraint configuration (total of 36 tests). Three PMHS were tested in a purely lateral (90° from frontal) impact direction; 4 were tested in an oblique impact (60° from frontal). All subjects were restrained by a 3-point seatbelt. Occupant motion was tracked with a 3D optoelectric high speed motion capture system. For all restraint configurations, the 60° oblique impact angle was associated with greater lateral head excursion than the 90° impact angle. This unexpected result reflects the increased axial rotation of the torso in the oblique impacts, which allowed the shoulder to displace more relative to the shoulder belt and thus the head to displace more relative to the sled buck. Restraint engagement of the torso and shoulder was actually greater in the purely lateral impacts than in the oblique impacts. Pretensioning significantly reduced lateral head excursion (175 mm average in the low-severity tests across all restraint configurations).
Subject(s)
Accidents, Traffic , Automobile Driving , Seat Belts , Acceleration , Adult , Biomechanical Phenomena , Cadaver , Equipment Design , Humans , Male , Middle Aged , Models, Biological , Rib Fractures/epidemiology , Shoulder/physiology , Spinal Injuries/epidemiology , Video RecordingABSTRACT
INTRODUCTION: We examined the accuracy of research participant characterizations of motor vehicle collisions (MVC). METHODS: We conducted an emergency department-based prospective study of adults presenting for care after experiencing an MVC. Study participants completed a structured clinical interview that assessed the number of lanes of the road where the collision took place, vehicle type, road condition, speed limit, seat belt use, airbag deployment, vehicle damage, time of collision, and use of ambulance transportation. Study participant data were then compared with information recorded by Michigan State Police at the scene of the MVC. Agreement between research participant reports and police-reported data were assessed by using percentage agreement and κ coefficients for categorical variables and correlation coefficients for continuous variables. RESULTS: There were 97 study participants for whom emergency department interviews and Michigan State Police Report information were available. Percentage agreement was 51% for number of lanes, 76% for car drivability, 88% for road condition, 91% for vehicle type, 92% for seat belt use, 94% for airbag deployment, 96% for speed limit, 97% for transportation by ambulance, and 99% for vehicle seat position. κ values were 0.32 for seat belt use, 0.34 for number of lanes, 0.73 for vehicle type, 0.76 for speed limit, 0.77 for road condition, 0.87 for airbag deployment, 0.90 for vehicle seat position, and 0.94 for transport by ambulance. Correlation coefficients were 0.95 for the time of the collision, and 0.58 for extent of damage to the vehicle. Most discrepancies between patients and police about extent of vehicle damage occurred for cases in which the patient reported moderate or severe damage but the police reported only slight damage. CONCLUSION: For most MVC characteristics, information reported by research participants was consistent with police-reported data. Agreement was moderate or high for characteristics of greatest relevance to injury biomechanics. These results suggest that research participant report is an acceptable source of collision information.