Survivability of a Tesla collision into a non-operational crash attenuator in Mountain View, CA.

OBJECTIVE: On March 23, 2018 a Tesla Model X driver was killed in Mountain View, CA after colliding with a previously collapsed crash attenuator at a speed of 31.7 m/s (70.8 mph). The attenuator, which must be repaired following a collision, had been struck 11 days prior by a 2010 Toyota Prius at a minimum speed of 33.9 m/s (75.8 mph). The Toyota driver survived. The maintenance of traffic safety hardware and benefit of the crash attenuator are evaluated. METHODS: Public information from an NTSB investigation is used to evaluate crash impact severity. Vehicle crash data from Event Data Recorders (EDRs) are compared with test data for the SCI Smart Cushion 100GM crash attenuator. An idealized triangular crash pulse is used to estimate longitudinal peak impact acceleration, and longitudinal impact energy is calculated. The medical outcomes for drivers are considered. RESULTS: The California Department of Transportation (Caltrans) maintenance and repair program for safety critical traffic safety hardware was found to be ineffective. The Tesla collision into the nonfunctional attenuator was estimated have roughly three times the impact force to the passenger compartment as it would have been if striking a functional attenuator. CONCLUSIONS: The Tesla driver could have survived the collision had the crash attenuator been functional. Roadway management and timely maintenance of safety critical traffic hardware are necessary to ensure safety.

Impaired driving: A case report. Pickup truck centerline crossover collision with medium-size bus on U.S. Highway 83, Concan, Texas, United States.

Objective: The objective of this communication is to describe a crash involving an impaired pickup truck driver who crossed the centerline and struck a medium-size bus carrying senior adults restrained with lap-only belts that resulted in 13 fatalities.Methods: Document review of the National Transportation Safety Board investigation was performed. Documents are available at: https://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=61581&CFID=2452299&CFTOKEN=9e7f5cd49ac23dc3-47A7BE1A-B81A-1A8F-7B1554A90617B722.Results: Prior to the crash, the erratic movement of the pickup truck being driven by a 20-year-old man was videotaped by witnesses in a following vehicle (https://www.youtube.com/watch?v=jsGsbYTwWbM). The 14.5-min cell phone recording demonstrated the pickup truck swerving repeatedly over the double yellow center line and onto the shoulder. The recording ended before the crash. While rounding a curve in the roadway, the pickup crossed the centerline and struck a medium-size bus with 14 occupants. All but one of the rearmost bus occupants were fatally injured in the collision. The pickup driver survived with serious injuries. Following the crash, toxicology testing found that the pickup truck driver had used marijuana in combination with a prescription benzodiazepine, clonazepam. The bus occupants ranged in age from 64 to 87 years old and all were wearing the available restraints, which included lap-shoulder belts and air bags (both of which deployed) for the driver and front seat passenger. Of the 12 rear passenger seats, 8 were equipped with traveling retractor lap belt assemblies and the 2-person bench seats in the last row on each side of the bus were equipped with manually adjustable lap belt assemblies.Conclusions: The failure of the truck driver to maintain control of his vehicle was due to impairment stemming from his use of marijuana in combination with misuse of a prescribed medication, clonazepam. Following the crash, the pickup driver was sentenced to 55 years in prison. Improved countermeasures including guidance and access to improved roadside testing methods, expanded law enforcement training to detect impaired drivers, enhanced enforcement regarding impairment by combinations of drugs or drugs and alcohol, as well an evaluation and implementation of data-driven strategies are needed to reduce fatalities, injuries, and crashes involving drivers impaired by alcohol and other drugs. The lap belts provided insufficient protection for the passengers seated in the rear of the bus aft of the intrusion zone; standard installation by vehicle manufacturers of lap-shoulder belts on medium-size as well as larger buses (now required) could mitigate the risk of injury in the event of a crash.

Fatal crash between a car operating with automated control systems and a tractor-semitrailer truck.

OBJECTIVE: The objective of this investigation was to evaluate the interaction between an SAE level 2 automated vehicle and the driver, including the limitations imposed by the vehicle on the driver. METHODS: A case study of the first fatal crash involving a vehicle operating with an automated control system was performed using scene evidence, vehicle damage, and recorded data available from the vehicle, and information from both drivers, including experience, phone records, computer systems, and medical information, was reviewed. RESULTS: System performance data downloaded from the car indicated that the driver was operating it using the Traffic-Aware Cruise Control and Autosteer lane-keeping systems, which are automated vehicle control systems within Tesla's Autopilot suite. As the car crested the hill, a tractor trailer began its left turn onto a crossing roadway. Although reconstruction of the crash determined that there was sufficient sight distance for both drivers to see each other and take action, neither responded to the circumstances leading to the collision. Further, based on the speeds of the vehicles and simulations of the truck's path, the car driver had at least 10.4 s to detect the truck and take evasive action. Neither the car driver nor the Autopilot system changed the vehicle's velocity. At the time of the crash, the system performance data indicated that the last driver interaction with the system was 1 min 51 s prior when the cruise control speed was set to 74 mph. The driver was operating the vehicle using the Autopilot system for 37 of the 41 min in the last trip. During this period, the vehicle detected the driver's hands on the steering wheel for a total of 25 s; each time his hands were detected on the wheel was preceded by a visual alert or auditory warning. CONCLUSIONS: The National Transportation Safety Board (NTSB) determined that the probable cause of the Williston, Florida, crash was the truck driver's failure to yield the right of way to the car, combined with the car driver's inattention due to overreliance on vehicle automation, which resulted in the car driver's lack of reaction to the presence of the truck. Contributing to the car driver's overreliance on the vehicle automation was the car's operational design, which permitted the driver's prolonged disengagement from the driving task and his use of the automation in ways inconsistent with guidance and warnings from the manufacturer.

Medical investigation after a motorcoach strikes the rear of a tractor semitrailer parked on the highway; 13 fatal.

OBJECTIVE: The objective of this study was to examine the medical conditions of 2 commercial drivers and the effects of physical barriers to occupant egress in a crash involving a tractor trailer and a motorcoach in order to assess and identify the factors that caused the crash and had a significant effect on occupant extrication. METHODS: Physical evidence from the scene, video evidence, commercial driver information, phone records, toxicology findings, autopsy results, and personal medical information were reviewed. RESULTS: On October 23, 2016, at 5:16 a.m., a motorcoach carrying a driver and 42 passengers struck the rear of a stopped semitrailer occupied by its driver in the center-right lane of Interstate 10 at highway speed outside Palm Springs, California. The motorcoach driver and 12 passengers died; 11 passengers were seriously injured. All traffic had been stopped on I-10 early that morning to allow electrical lines to be strung over the highway. Security camera footage showed that the truck arrived at the end of a traffic queue 2 min before traffic flow resumed. Physical evidence indicated that the truck's parking brake was still engaged at the time of the collision about 2 min later. The truck driver had a body mass index (BMI) between 45.6 and 50 kg/m2, which placed him at very high risk of moderate to severe obstructive sleep apnea; he also inaccurately recalled that he had been stopped for 20-25 min and had placed the vehicle in gear just before the collision. The motorcoach driver was on the return leg of an overnight trip to a casino. Based on his phone records, known driving time, and security camera footage, at the time of the collision he had had 4 h of sleep opportunity in the preceding 35 h. There was no evidence that the motorcoach driver attempted any evasive action before the collision. In addition, postmortem testing revealed a hemoglobin A1C of 11.4%, indicating poorly controlled diabetes; this was apparently undiagnosed prior to the crash. The motorcoach was equipped with a single loading door at the front of the vehicle; it was rendered inoperable by the collision. Emergency egress was initially carried out through the emergency exit windows, but they repeatedly swung shut, impeding passengers' efforts to exit. Emergency responders eventually cut open the bus wall to create a larger means of egress. Overall, it took almost 3 h to extricate the occupants from the vehicle. CONCLUSIONS: The National Transportation Safety Board (NTSB) determined that the probable cause of the accident was the truck driver's falling asleep, most likely due to undiagnosed moderate-to-severe obstructive sleep apnea, and the motorcoach driver's failure to identify the stopped truck as a hazard requiring evasive action, most likely as the result of fatigue. Additional easy-to-use emergency exits would have decreased the time to extricate the occupants.

Changes in baseline concussion assessment scores following a school bus crash.

OBJECTIVE: The objective of this article is to present concussion assessment data for 30 male athletes prior to and after being involved in a large school bus crash. The athletes on the bus, all male and aged 14-18 years, were participants in their school's concussion management program that included baseline and postinjury testing using Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). METHODS: This case study described changes in concussion assessment scores for 30 male athletes following a primarily frontal school bus crash. Data from the school's concussion management program, including baseline test data and postinjury assessment data, were reviewed. Athletes who required multiple postinjury assessments by the program were identified as having had significant cognitive changes as a result of the bus crash. RESULTS: Twenty-nine of 30 athletes were injured. One had lumbar compression fractures; others had various lacerations, abrasions, contusions, sprains, and nasal fractures. ImPACT data (postcrash) were available for all 30 athletes and 28 had available precrash baseline data. A total of 16 athletes (53.3%) had significant cognitive changes indicated by changes in their concussion assessment scores, some of which took months to improve. CONCLUSION: This case study highlights a unique opportunity to evaluate concussion assessment data from 30 male athletes involved in a high-speed school bus crash. Further, these data provide additional insight into assessing the effectiveness of current school bus occupant protection systems.

23 years of toxicology testing fatally injured pilots: Implications for aviation and other modes of transportation.

UNLABELLED: Use of over-the-counter, prescription, and illicit drugs is increasing in the United States (US). Many of these drugs are psychoactive and can affect the user's ability to safely operate a vehicle. However, data about drug use by vehicle operators is typically limited to a small proportion of operators and a short list of drugs. For instance, required testing for commercial vehicle operators following most accidents is limited to a urine test for 11 drugs. By comparison, the Federal Aviation Administration (FAA), routinely tests fatally injured pilots' blood and tissues for hundreds of compounds. This study used the results from these tests to assess drug use in aviation. METHODS: Using matched data from the FAA's Civil Aerospace Medical Institute toxicology database and the National Transportation Safety Board's (NTSB's) aviation accident database, this study examined trends in the prevalence of over-the-counter, prescription, and illicit drugs identified in toxicology tests of fatally injured pilots between 1990 and 2012. Cases that failed to match or where toxicology testing had not been performed were excluded. Pilots identified by the NTSB investigation as being the "flying pilot" at the time of the accident and results from blood or tissues were included. Toxicology results for ethanol and other alcohols were not included. Positive test results were categorized by drug type and potential for causing impairment. Analysis used SPSS Version 19.1 to perform linear by linear chi-squared statistics. RESULTS: The study included 6677 pilots or 87% of the eligible subjects. The large majority were male (98%) and flying general aviation operations (96%) at the time of their fatal accident. There were increasing trends in pilots' use of all drugs, potentially impairing drugs, drugs used to treat potentially impairing conditions, drugs designated as controlled substances, and illicit drugs. The most common potentially impairing drug pilots had used was diphenhydramine, a sedating antihistamine that is an active ingredient in many over-the-counter allergy formulations, cold medicines, and sleep aids in the US. Although evidence of illicit drug use was found only in a small number of cases, the percentage of pilots testing positive for marijuana use increased during the study period, mostly in the last 10 years.

Fatal Consequences: Obstructive Sleep Apnea in a Train Engineer.

This special report describes the findings of the National Transportation Safety Board's investigation into the probable cause of the derailment of a Metro-North passenger train in the Bronx, New York on December 1, 2013, that resulted in 4 deaths and injuries to 59 additional persons. A key finding in the medical investigation was the engineer's post-accident diagnosis of severe, obstructive sleep apnea, and the probable cause of the accident was determined to be the result of the engineer having fallen asleep while operating the train. This accident highlights the importance of screening, evaluating, and ensuring adequate treatment of obstructive sleep apnea, particularly among patients working in positions where impairment of physical or cognitive function or sudden incapacitation may result in serious harm to the public.

Exceeding the speed limit: prevalence and determinants in Iran.

Speeding is one of the most common risk behaviours associated with crashes causing signficant injury. The objective of this study is to explore the prevalence and determinants of speeding on a road between Tehran and Hamadan, Iran. In a cross-sectional study in 2009, stretches of the road were studied including three groups of posted speed limits: < 50 km/h, 50-100 km/h and > 100 km/h. Each stretch was evaluated both in daylight and dark. Randomly identified driver's speed was checked by a handheld speed camera and then the driver was invited to participate in a survey. Statistical analysis was performed using Chi-Square, crude and adjusted odds ratio, 95% confidence interval and multiple logistic regression models. Overall, 52.8% of the drivers were travelling more than 10 km/h above the posted limit. Where limits were < 50 km/h, 74.6% of drivers were speeding. This declined to 46.9% for sections with limits between 50 and 100 km/h and to 36.9% for sections posted more than 100 km/h. Finally, more than half the drivers were observed to be speeding. Driving more than the posted limit was far more likely on the areas with the lowest posted speed limits, personal passenger vehicles, modern vehicles not using seat belts, and male drivers.

The epidemiology of mountain bike park injuries at the Whistler Bike Park, British Columbia (BC), Canada.

OBJECTIVE: To describe the epidemiology of injuries sustained during the 2009 season at Whistler Mountain Bike Park. METHODS: A retrospective chart review was performed of injured bike park cyclists presenting to the Whistler Health Clinic between May 16 and October 12, 2009. RESULTS: Of 898 cases, 86% were male (median age, 26 years), 68.7% were Canadian, 19.4% required transport by the Whistler Bike Patrol, and 8.4% arrived by emergency medical services. Identification of 1759 specific injury diagnoses was made, including 420 fractures in 382 patients (42.5%). Upper extremity fractures predominated (75.4%), 11.2% had a traumatic brain injury, and 8.5% were transferred to a higher level of care: 7 by helicopter, 62 by ground, and 5 by personal vehicle. Two patients refused transfer. CONCLUSIONS: Mountain bikers incurred many injuries with significant morbidity while riding in the Whistler Mountain Bike Park in 2009. Although exposure information is unavailable, these findings demonstrate serious risks associated with this sport and highlight the need for continued research into appropriate safety equipment and risk avoidance measures.

Trauma registries: history, logistics, limitations, and contributions to emergency medicine research.

Trauma registries have been designed to serve a number of purposes, including quality improvement, injury prevention, clinical research, and policy development. Since their inception over 30 years ago, there are increasingly more institutions with trauma registries, many of which submit data to a national trauma registry. The goal of this review is to describe the history, logistics, and characteristics of trauma registries and their contribution to emergency medicine and trauma research. Discussed in this review are the limitations of trauma registries, such as variability in quality and type of the collected data, absence of data pertaining to long-term and functional outcomes, prehospital information, and complications as well as other methodologic obstacles limiting the utility of registry data in clinical and epidemiologic research.

Serious injuries related to the Segway® personal transporter: a case series.

STUDY OBJECTIVE: We describe a case series of emergency department (ED) visits for injuries related to the Segway® personal transporter. METHODS: This was a retrospective case review using a free-text search feature of an electronic ED medical record to identify patients arriving April 2005 through November 2008. Data were hand extracted from the record, and further information on admitted patients was obtained from the hospital trauma registry. RESULTS: Forty-one cases were included. The median age was 50 years, and 30 patients (73.2%) were women. Twenty-nine (70.7%) of the patients resided outside the District of Columbia, Maryland, and Virginia, and 32 (78.1%) arrived between June and September. Seven (17.1%) patients had documented helmet use. Ten (24.4%) were admitted. Four patients (40% of admitted patients) required admission to the ICU. CONCLUSION: The severity of trauma in this case series of patients injured by the use of the self-balancing personal transporter is significant. Further investigation into the risks of use, as well as the optimal length and type of training or practice, is warranted. A distinct E-code and Consumer Product Safety Commission's product code is needed to enable further investigation of injury risks for this mode of transportation.

The effect of driver age on the incidence and severity of upper extremity injuries due to second generation front air bag deployment.

This study used NHTSA NASS/CDS data to examine whether advancing age was associated with a higher incidence and severity of front airbag-related upper extremity injury (UEI). Using a retrospective cohort design we analyzed weighted data from 1998-2007 for. The study population consisted of lap/shoulder belted people over 16 years of age who were driving passenger vehicles with model years 1998-2003 and were involved in a frontal crash where their front airbag deployed. Drivers who were ejected, involved in a vehicle rollover, or accompanied by a passenger sitting directly behind them were omitted. The exposure variable was age and the outcome variables were UEI incidence and severity. Associations were adjusted for gender, seat track position, vehicle type, vehicle weight, intrusion, and delta-v. Logistic regressions were performed using SAS survey procedures to account for the complex survey design. Overall, 42% of drivers sustained an UEI. Advancing age was associated with a higher incidence (p<0. 0001) and severity (p<0. 0001) of UEI. Nineteen percent of drivers sustained an UEI related to the airbag. No significant differences in the incidence or severity of airbag-related UEI were found between young drivers and older driver age groups. The degree of severity due to airbag-related UEI was generally minor. The majority of airbag-related UEI appeared to shift slightly from abrasions to contusions with aging. These results indicate that UEI due to depowered airbag deployment is common but not disproportionately high among older drivers, and injury severity is generally minor across all age groups.

National survey of emergency department alcohol screening and intervention practices.

STUDY OBJECTIVE: We describe current alcohol screening and brief intervention practices in emergency departments (EDs) at Level I and Level II trauma centers and characterize ED directors' attitudes and perceived barriers associated with these practices among injured patients in the ED. METHODS: ED directors at Level I and Level II trauma centers were surveyed about current alcohol screening and intervention practices in the ED, as well as knowledge, attitudes, and perceived barriers to these practices. RESULTS: Nearly half (46.0%) of ED directors surveyed responded. The majority (64.5%) reported using a serum alcohol level to routinely screen for unhealthy alcohol use; only 23.6% routinely use standardized instruments. Sixty-five percent of ED directors support screening and 70% support intervention among injured ED patients. Only 15% reported having formal screening and intervention policies in their ED, and 9% reported offering brief alcohol intervention by trained personnel. The most commonly perceived barriers to implementation are provider time (83%) and financial resources (55%). Of injured patients identified as exhibiting alcohol misuse, few (12%) receive brief intervention conducted by trained personnel. CONCLUSION: Current alcohol screening and brief intervention practices are lagging behind national guidelines. Although the majority of ED directors support the idea of alcohol screening and intervention, these beliefs have not yet been translated to routine clinical care.

Weekend emergency department visits in Nebraska: higher utilization, lower acuity.

BACKGROUND: We know very little about differences in Emergency Department (ED) utilization and acuity on weekends compared with weekdays. Understanding such differences may help elucidate the role of the ED in the health care delivery system. STUDY OBJECTIVE: To compare patterns of ED use on weekends with weekdays and analyze the differences between these two groups. METHODS: The Health Care Utilization Project (HCUP) is a national state-by-state billing database from acute-care, non-federal hospitals. Data from Nebraska in 2004 was used to compare ED-only patient visits (patients discharged home or transferred to another health care facility) and ED-admitted visits (patients admitted to the same hospital after an ED visit) for weekend vs. weekday frequency, billed charges, sex, age, and primary payer. RESULTS: Of all non-admitted patients who visited the ED, 34.5% came in on weekends. This yielded ED utilization rates of 25 visits/1,000 people on weekdays and 33 visits/1,000 people on weekends, an increase of 32% on weekends. Weekend-only ED patients of all ages and payer categories were charged lower hospital facility fees than weekday-only ED patients; USD 777 vs. USD 921, respectively (p < 0.001). Weekend ED patients were less likely to be admitted and less likely to die while in the ED (2 deaths/1000 ED visits for weekend-only patients vs. 3 deaths/1000 ED visits for weekday-only [p < 0.001]). CONCLUSIONS: In Nebraska, EDs care for a greater number of low-acuity patients on weekends than on weekdays. This highlights the important role EDs play within the ambulatory care delivery system.

Mastitis and methicillin-resistant Staphylococcus aureus (MRSA): the calm before the storm?

BACKGROUND: Post-partum mastitis is a common infection in breastfeeding women, with an incidence of 9.5-16% in recent literature. Over the past decade, community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a significant pathogen in soft-tissue infections presenting to the emergency department. The incidence of mastitis caused by MRSA is unknown at this time, but likely increasing. OBJECTIVES: We review the data on prevention and treatment of mastitis and address recent literature demonstrating increases in MRSA infections in the post-partum population and how we should change our practices in light of this emerging pathogen. CASE REPORT: We present a case of simple mastitis in a health care worker who failed to improve until treated with antibiotics appropriate for a MRSA infection. CONCLUSION: Recent evidence suggests that just as MRSA has become the prominent pathogen in other soft-tissue infections, mastitis is now increasingly caused by this pathogen. Physicians caring for patients with mastitis need to be aware of this bacteriologic shift to treat appropriately.