Validating the danger of vehicular protective devices and bowel injury.

INTRODUCTION: Protective devices such as seat belts and airbags have improved the safety of motor vehicle occupants, but limited data suggest they may be associated with increased blunt bowel (small bowel or colon) injuries (BI). Unfortunately, this risk is unquantified. METHODS: We analyzed the National Trauma Data Bank (2017-2019) using ICD-10 codes to identify adult motor vehicle occupants with BI who underwent surgical repair. We used logistic regression modeling to compare the risk of undergoing surgical repair for BI after using a protective device. RESULTS: Of 2,848,592 injured patients, 475,546 (16.7%) were motor vehicle occupants. Only 1.2% (n = 5627/475,546) of patients underwent a bowel repair or resection. Using a seat belt only was associated with an adjusted OR of 2.09 (95% CI 1.91, 2.28) for undergoing a bowel repair/resection when adjusting for Injury Severity Score (ISS) and age. Airbag deployment without a seat belt had an adjusted OR of 1.46 (95% CI 1.31, 1.62), while both devices combined conferred an OR of 3.27 (95% CI 3.02, 3.54). However, using a seat belt was protective against death with an OR of 0.50 (95% CI 0.48, 0.53), adjusted for age, sex, Charlson Comorbidity Score, and ISS. CONCLUSION: Seat belts and airbags are essential public health safety interventions and protect against death in motor vehicle-associated injuries. However, patients involved in MVCs with airbag deployment or while wearing a seat belt are at an increased risk of bowel injury requiring surgery compared to unrestrained patients, despite these events being relatively uncommon.

Military training-related abdominal injuries and diseases: Common types, prevention and treatment.

Military training is intense, difficult and often dangerous, so all kinds of injuries or diseases frequently occur during training. Most of the previous studies and reviews on military training-related injuries focused on musculoskeletal system, whereas there are no reviews of abdominal injuries and diseases. Although the incidence of military training-related abdominal injuries and diseases is relatively low, the patients' condition is often critical especially in the presence of abdominal organ injury, leading to multi-organ dysfunction syndrome and even death. This paper elaborates on common types of military training-related abdominal injuries and diseases as well as the prevention and treatment measures, which provides some basis for scientific and reasonable training and improvement of medical security.

How to reduce the risk of organ injuries during surgical instrument insertion in laparoscopic surgery: Pushing/pressing force analysis using forceps with sensors.

INTRODUCTION: In laparoscopic surgery, surgical instruments are inserted from a trocar to the target organ in a blind fashion, which carries a risk of organ injury. To clarify the risks associated with surgical instrument insertion, we measured grip strength and pushing/pressing force during surgical instrument insertion in laparoscopic surgery. METHODS: Using forceps with sensors inside a trocar, 10 urologists performed a laparoscopic procedure in pigs, in which they were asked to touch the abdominal wall. The surgeons closed their eyes during the procedure and stopped moving the forceps when they felt them come into contact with the abdominal wall. They were ordered to grip the forceps strongly or softly and to move them rapidly or slowly during the procedure. Grip strength and the pushing/pressing force when the forceps hit the abdominal wall were measured and analyzed. RESULTS: The mean pushing/pressing force when the surgeons gripped the forceps strongly and moved them rapidly (strong/rapid), strongly/slowly, softly/rapidly, and softly/slowly were 2.8, 2.0, 1.7, and 1.1 N, respectively. The pushing/pressing force was significantly greater when the surgeons gripped the forceps strongly, regardless of the forceps speed (P < .001). The pushing/pressing force was significantly greater when the surgeons moved the forceps rapidly, regardless of grip strength (P < .001). CONCLUSIONS: When surgeons insert laparoscopic instruments through trocars, the instruments should be gripped softly and moved slowly to avoid organ injuries.

Transcholecystic Contrast-Enhanced Ultrasound-Guided Percutaneous Transhepatic Biliary Drainage for Central Bile Duct Protection During Thermal Tumor Ablation.

Intraductal cooling via a percutaneous transhepatic biliary drainage tube holds great promise in facilitating thermal ablation of liver tumors adjacent to the central bile ducts. However, the difficulties and complications associated with puncturing nondilated bile ducts are greater than those associated with puncturing dilated bile ducts. As reported here, percutaneous transcholecystic contrast-enhanced ultrasound was performed in 7 patients to visualize the nondilated bile ducts and guide percutaneous transhepatic biliary drainage, thus facilitating the intraductal cooling-assisted thermal ablation process. The procedures were technically successful in all 7 patients, and no major complications were recorded during the follow-up period.

Respuesta de los autores: Reanimación cardiopulmonar extrahospitalaria / Author’s reply: Out-of-hospital cardiopulmonary resuscitation

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Defining the medical coverage of ballistic protection to the pelvis and thigh.

INTRODUCTION: Pelvis, lower limb and associated genital injury caused by explosive devices was responsible for mortality and considerable long-term morbidity for the UK Armed Forces during combat operations in Afghanistan, resulting in the issue of a pelvic protection system in 2010. The aim of this current research was to determine the medical coverage of the pelvis and thigh and to define the vertical dimensions of ballistic protective material for future pelvic protection (PP). METHOD: CT scans from 120 male UK Armed Forces personnel were analysed to identify the anthropometric landmarks and vertical boundaries of coverage for the pelvis and thigh. Pelvic height was the vertical distance between the upper border of the iliac crest in the midaxillary plane to the most inferior point of the ischial tuberosity of the pelvis. Upper thigh height was proposed as a 100 mm fixed distance below the ischial tuberosities, enabling a tourniquet to be reproducibly applied. These distances were compared with the ballistic component of the five sizes of tier 1 PP using a paired t-test. RESULTS: The vertical components of coverage measured using CT scans were all significantly less (p<0.01) compared with all five sizes of tier 1 PP; for example, the ballistic component of the smallest size of tier 1 PP measured 410 mm, which was larger than the 99th percentile male, which measured 346 mm on CT scans. CONCLUSIONS: While all sizes of tier 1 PP provide coverage to the pelvis and upper thigh structures, there is an opportunity to optimise future PP. For example, comparing the large size of tier 1 PP to the 50th percentile male demonstrated an opportunity to reduce the ballistic protective component by 31%. Reducing the quantity of material used will improve heat dissipation and user comfort and reduce material mass and acquisition costs.

Morbid Obesity's Silver Lining: An Armor for Hollow Viscus in Blunt Abdominal Trauma.

BACKGROUND: Morbid obesity is usually accompanied by both subcutaneous and visceral fat accumulation. Fat can mimic an air bag, absorbing the force of a collision. We hypothesized that morbid obesity is mechanically protective for hollow viscus organs in blunt abdominal trauma (BAT). METHODS: The National Trauma Data Bank (NTDB) was queried for BAT patients from 2013 to 2015. We looked at the rate of gastrointestinal (GI) tract injuries in all BAT patients with different BMIs. A subset analysis of BAT patients with operative GI tract injuries was performed to evaluate the need for abdominal operation. Multivariate analyses were carried out to identify factors independently associated with increased GI tract injuries and associated abdominal operations. RESULTS: A total of 100,459 BAT patients were evaluated in the NTDB. Patients with GI tract injury had a lower proportion of morbidly obese patients [body weight index (BMI) ≥ 40 kg/m2)] (3.7% vs. 4.2%, p = 0.015) and instead had more underweight patients (BMI < 18.5) (5.9% vs. 5.0%, p < 0.001). The risk of GI tract injury decreased 11.6% independently in morbidly obese patients and increased 15.7% in underweight patients. Of the patients with GI tract injuries (N = 11,467), patients who needed a GI operation had a significantly lower proportion of morbidly obese patients (3.2% vs. 5.3%, p < 0.001). The risk of abdominal operation for GI tract injury decreased 57.3% independently in morbidly obese patients. Compared with underweight patients, morbidly obese patients had significantly less GI tract injury (6.0% vs. 13.3%, p < 0.001) and associated abdominal operation rates (65.2% vs. 73.3%, p < 0.001). CONCLUSION: Obesity is protective in BAT. This translates into lower rates of GI tract injury and operation in morbidly obese patients. In contrast, underweight patients appear to suffer a higher rate of GI tract injury and associated GI operations.

Effect of 2 Enteral Feeding Schedules on Intra-abdominal Pressure in Patients Receiving Mechanical Ventilation: A Randomized Controlled Trial.

BACKGROUND: Elevated intra-abdominal pressure is associated with morbidity in critically ill patients. Enteral feeding is important for these patients but may cause complications. OBJECTIVE: To compare the effects of 2 intermittent feeding schedules on intra-abdominal pressure in patients receiving mechanical ventilation. METHODS: A single-blinded, prospective, parallel-group, randomized controlled trial was conducted in an intensive care unit in a teaching hospital in Egypt. Fifty adult patients requiring more than 48 hours of mechanical ventilation were enrolled. Patients were randomly sorted into 2 study groups. The intervention group received intermittent enteral feedings 5 times daily at 4-hour intervals. The control group received intermittent enteral feedings 10 times daily at 2-hour intervals. Both groups fasted for 8 hours overnight. Intra-abdominal pressure was measured 7 times: at admission and before and after the first 3 feedings on the third day of the intensive care unit stay. RESULTS: One-way repeated-measures analysis of variance showed that mean intra-abdominal pressure was higher in the control group before the first feeding (t = 2.27, P = .03) but was higher in the intervention group after the second feeding (t = 2.51, P = .02) and after the third feeding (t = 2.41, P = .02). Vomiting and diarrhea were not significantly different between the groups. More constipation and abdominal distension occurred in the intervention group than in the control group. CONCLUSION: Intra-abdominal pressure was not significantly affected by feeding interval. However, reducing the time interval between intermittent enteral feedings may minimize the risk for constipation and abdominal distension.

Evaluating the "cushion effect" among children in frontal motor vehicle crashes.

BACKGROUND: The "Cushion Effect," the phenomenon in which obesity protects against abdominal injury in adults in motor vehicle accidents, has not been evaluated among pediatric patients. This work evaluates the association between subcutaneous fat cross-sectional area, quantified using analytic morphomic techniques and abdominal injury. METHODS: This retrospective study includes 119 patients aged 1 to 18years involved in frontal impact motor vehicle accidents (2003-2015) with computed tomography scans. Subcutaneous fat cross-sectional area was measured and converted to age- and gender-adjusted percentiles from population-based normative data. Multivariable analysis determined the risk of the primary outcome, Maximum Abbreviated Injury Scale (MAIS) 2+ abdominal injury, after adjusting for age, weight, seatbelt status, and impact rating. RESULTS: MAIS 2+ abdominal injuries occurred in 20 (16.8%) of the patients. Subcutaneous fat area percentile was not significantly associated with MAIS 2+ abdominal injury on multivariable logistic regression (adjusted Odds Ratio, 0.86; 95% CI, 0.72-1.03; p=0.10). DISCUSSION: The "cushion effect" was not apparent among pediatric frontal motor vehicle crash victims in this study. Future work is needed to investigate other analytic morphomic measures. By understanding how body composition relates to injury patterns, there is a unique opportunity to improve vehicle safety design. LEVEL OF EVIDENCE: Prognosis Study, Level III.

Study of chest injuries to 3-year-old child occupants seated in impact shield and 5-point harness CRSs.

OBJECTIVE: The objective of this study was to investigate whether the 5-point harness or the impact shield child restraint system (CRS) or both have the potential to cause chest injuries to children. This is determined by examining whether the loading to the chest reaches the internal organ injury threshold for children. METHOD: The chest injury risk to a child occupant in a CRS was investigated using Q3 dummy tests, finite element (FE) simulations (Q3 dummy and human models), and animal tests. The investigation was done for 2 types of CRSs (i.e., the impact shield CRS and 5-point harness CRS) based on the UN R44 dynamic test specifications. RESULTS: The tests using a Q3 dummy indicated that although the chest deflection of the dummy in the impact shield CRS was large, it was less than the injury threshold (40 mm). Computational biomechanics simulations (using finite element FE analysis) showed that the Q3 dummy's chest is loaded by the shield and deforms substantially under this load. To clarify whether chest injuries due to chest compression can occur with an impact shield or with the 5-point harness CRS, 7 experiments were performed using Tibetan miniature pigs with weights ranging from 9.7 to 13 kg. Severe chest and abdominal injuries (lung contusion, coronary artery laceration, liver laceration) were found in the tests using the impact shield CRS. No chest injuries were present when using the 5-point harness CRS. CONCLUSION: When using the impact shield CRS, the chest deformed substantially in dummy tests and FE simulations, and chest and abdominal injuries were observed in pig tests. It is possible that these chest injuries could also occur to child occupants sitting in the impact shield CRS.

Previous Laparotomy Scar Preventing Abdominal Injury from Gunshot Wound.

Diagnostic laparoscopy has been used in select patients with penetrating abdominal trauma. Here we present a case report where a midline surgical scar from a previous trauma laparotomy potentially prevented intra-abdominal injury. Furthermore, laparoscopy was used to exclude other intra-abdominal injuries and retrieve the projectile from within a hematoma cavity. This avoided the morbidity of a trauma laparotomy.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles.

INTRODUCTION: Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. METHODS: A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. RESULTS AND CONCLUSIONS: Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

An experimental study in six fresh human cadavers using a novel approach to avoid abdominal wall incisions in total colectomy: totally transanal laparoendoscopic single-site pull-through colectomy with J-pouch creation.

BACKGROUND: The use of transanal laparoscopic access to completely avoid abdominal wall incisions represents the most current evolution in minimally invasive surgery. The combination of single-site surgery and natural orifice transluminal endoscopic surgery (NOTES™) can be used for totally transanal laparoendoscopic pull-through colectomy with J-pouch creation (TLPC-J). The aim of the present study was to provide evidence for the feasibility of TLPC-J in adult human cadavers. METHODS: TLPC-J was performed in six fresh adult human cadavers. The procedure involved endorectal submucosal dissection from 1 cm above the dentate line to a point above the peritoneal reflection, where the rectal muscle was divided circumferentially. The edge of the mucosal cuff was closed distally in order to prevent fecal contamination and the endorectal tube was placed back into the abdomen. A Triport+™ or QuadPort+™ system was introduced transanally, and it served as a multiport device (MD). Resection of the entire colon, mobilization of the distal ileal segment, and extracorporeal suture of the ileal J-loop were performed via the transanal approach. The J-pouch was created using Endo GIA™. After removal of the MD, the J-pouch was sutured to the rectal wall. RESULTS: TLPC-J was performed in all cadavers, with a mean operation duration of 236 ± 22 min. Conversion to either transabdominal laparoscopy or laparotomy was not required in any of the cadavers. No bowel perforation or damage to other organs was observed. The use of a curved endoscope greatly facilitated visualization during transanal laparoscopic dissection for partial and total colectomy, making the procedure feasible. All specimens were retrieved through the anus, eliminating the need for additional transabdominal incisions. CONCLUSIONS: TLPC-J was technically feasible in adult human cadavers, and abdominal wall incisions were not required. However, clinical studies are needed to determine its feasibility in living adults.

Injury patterns of rear seat occupants in frontal impact: an in-depth crash investigation study.

OBJECTIVE: Rear seat occupants are now at a higher risk of injury relative to front seat occupants and there is a need for enhanced protection. This study aimed to examine the pattern of injury, injury mechanisms and injury sources to restrained motor vehicle rear seat occupants involved in a frontal impact. METHODS: Cases involving restrained rear seat occupants aged 9 years and older involved in frontal crashes were prospectively collected from in-depth crash investigations collected in New South Wales and Victoria, Australia, between 2000 and 2010. Structured occupant and driver interviews were conducted to ascertain crash parameters, medical records were reviewed and detailed injury descriptions were recorded using the abbreviated injury scale (AIS). Vehicle and scene inspections were also conducted and injury sources determined. RESULTS: The dataset included 29 rear seat occupants aged 9-80 years. AIS2+ injuries were most commonly observed in the chest and abdomen. Chest injuries were more commonly observed in older occupants, while abdominal and thoracolumbar spine injuries were mostly observed in younger occupants. The seat belt was the most common source of injury to rear seat occupants. CONCLUSIONS: The seat belt is the most common source of injury to rear seat passengers in frontal impact with variations in injury with age. There is a need to provide appropriate belt fit and better control seat belt loads for rear seat passengers. This could be achieved, at least in part, with existing technologies currently used in front seat positions, although novel technologies may also be useful.

Finding the fifth intercostal space for chest drain insertion: guidelines and ultrasound.

OBJECTIVES: International guidelines exist for chest drain insertion and recommend identifying the fifth intercostal space or above, around the midaxillary line. In a recent study, applying these guidelines in cadavers risked insertion in the 6th intercostal space or below in 80% of cases. However, there are limitations of cadaveric studies and this investigation uses ultrasound to determine the intercostal space identified when applying these guidelines in healthy adult volunteers. METHODS: On each side of the chest wall in 31 volunteers, the position for drain insertion was identified using the European Trauma Course method, Advanced Trauma Life Support (ATLS) method, British Thoracic Society's 'safe triangle' and the 'traditional' method of palpation. Ultrasound imaging was used to determine the relationship of the skin marks with the underlying intercostal spaces. RESULTS: Five methods were assessed on 60 sides. In contrast to the cadaveric study, 94% of skin marks lay over a safe intercostal space. However, the range of intercostal spaces found spanned the second to the seventh space. In 44% of women, the inferior boundary of the 'safe triangle' and the ATLS guidelines located the sixth intercostal space or below. CONCLUSIONS: Current guidelines often identify a safe site for chest drain insertion, although the same site is not reproducibly found. In addition, women appear to be at risk of subdiaphragmatic drain insertion when the nipple is used to identify the fifth intercostal space. Real-time ultrasonography can be used to confirm the intercostal space during this procedure, although a safe guideline is still needed for circumstances in which ultrasound is not possible.

Guidelines for chest drain insertion may not prevent damage to abdominal viscera.

OBJECTIVES: Guidelines to improve the ease and safety of chest drain insertion recommend using the fifth intercostal space, around the midaxillary line (MAL). This study aimed to assess whether compliance with published guidelines reliably ensured such placement and avoided the potentially serious complications of subdiaphragmatic insertion and peripheral nerve injury. METHODS: Three international guidelines were assessed by identifying the intercostal space for chest drain insertion using 16 cadavers (32 sides) at a point 1 cm anterior to MAL. The European Trauma Course method was compared with the British Thoracic Society's 'safe triangle' and the ATLS course technique. RESULTS: The level most commonly found was the sixth intercostal space (43%; 41 of 96 sides). Overall the sixth space or below was found in 83% of insertions (80 of 96 sides). In the fifth intercostal space, the long thoracic nerve ran posterior to the marker placed in all cases and the lateral cutaneous branches of intercostal nerves arose anteriorly to the marker in all but one case. CONCLUSIONS: The results suggest these guidelines may result in insertion of chest drains below the fifth intercostal space, potentially risking injury to subdiaphragmatic structures. Peripheral nerves of the lateral thoracic wall appear safe from incisions 1 cm anterior to MAL.

A description of the severity of equestrian-related injuries (ERIs) using clinical parameters and patient-reported outcomes.

INTRODUCTION: Despite a number of injury prevention campaigns and interventions, horse riding continues to be a dangerous activity, resulting in more accidents per hour than motorcycling, skiing and football. Injuries are often serious, with one in four patients requiring admission to hospital. This study aims to describe the severity of equestrian-related injuries (ERIs) using both clinical parameters and patient-reported outcomes. PATIENTS AND METHODS: A retrospective study of all patients aged ≥18 years admitted to The Alfred Hospital between January 2003 and January 2008 with an ERI was performed. Specific clinical data were extracted from the medical record. In addition, a questionnaire was conducted identifying the details of the accident, the required recovery time and levels of ongoing pain and physical disability. RESULTS: During the study period 172 patients met the inclusion criteria. There were three deaths (2%). Eighty-two patients (48%) suffered head injuries. Forty-one patients (24%) were admitted to the ICU and 31 patients (18%) required mechanical ventilation. On discharge, 41 patients (24%) required transfer to a sub-acute rehabilitation facility. One-hundred-and-twenty-four patients (72%) completed the questionnaire. Thirty-nine respondents (31%) were not wearing a helmet. Among patients injured for more than 6 months, 38 (35%) still experienced moderate or severe pain or disability. Ninety-five patients had returned to work at the time of review, among which 47(50%) required longer than 6 months to recover, and 40 (42%) returned at a reduced capacity. CONCLUSIONS: The clinical and patient-reported outcomes of ERIs requiring hospital admission are poor. Persistent pain and disability are common, even up to 5 years post-injury. A large proportion of patients required longer than 6 months to return to work and many return at a reduced capacity.

The impact of seat belts and airbags on high grade renal injuries and nephrectomy rate in motor vehicle collisions.

PURPOSE: Motor vehicle collisions are the most common cause of blunt genitourinary trauma. We compared renal injuries with no protective device to those with seat belts and/or airbags using NTDB. Our primary end point was a decrease in high grade (grades III-V) renal injuries with a secondary end point of a nephrectomy rate reduction. MATERIALS AND METHODS: The NTDB research data sets for hospital admission years 2010, 2011 and 2012 were queried for motor vehicle collision occupants with renal injury. Subjects were stratified by protective device and airbag deployment. The AIS was converted to AAST renal injury grade and nephrectomy rates were evaluated. Intergroup comparisons were analyzed for renal injury grades, nephrectomy, length of stay and mortality using the chi-square test or 1-way ANOVA. The relative risk reduction of protective devices was determined. RESULTS: A review of 466,028 motor vehicle collisions revealed a total of 3,846 renal injuries. Injured occupants without a protective device had a higher rate of high grade renal injuries (45.1%) than those with seat belts (39.9%, p = 0.008), airbags (42.3%, p = 0.317) and seat belts plus airbags (34.7%, p <0.001). Seat belts (20.0%), airbags (10.5%) and seat belts plus airbags (13.3%, each p <0.001) decreased the nephrectomy rate compared to no protective device (56.2%). The combination of seatbelts and airbags also decreased total hospital length of stay (p <0.001) and intensive care unit days (p = 0.005). The relative risk reductions of high grade renal injuries (23.1%) and nephrectomy (39.9%) were highest for combined protective devices. CONCLUSIONS: Occupants of motor vehicle collisions with protective devices show decreased rates of high grade renal injury and nephrectomy. Reduction appears most pronounced with the combination of seat belts and airbags.

On and off the horse: mechanisms and patterns of injury in mounted and unmounted equestrians.

INTRODUCTION: The purpose of this study is to determine whether discrepant patterns of horse-related trauma exist in mounted vs. unmounted equestrians from a single Level I trauma center to guide awareness of injury prevention. METHODS: Retrospective data were collected from the University of Kentucky Trauma Registry for patients admitted with horse-related injuries between January 2003 and December 2007 (n=284). Injuries incurred while mounted were compared with those incurred while unmounted. RESULTS: Of 284 patients, 145 (51%) subjects were male with an average age of 37.2 years (S.D. 17.2). Most injuries occurred due to falling off while riding (54%) or kick (22%), resulting in extremity fracture (33%) and head injury (27%). Mounted equestrians more commonly incurred injury to the chest and lower extremity while unmounted equestrians incurred injury to the face and abdomen. Head trauma frequency was equal between mounted and unmounted equestrians. There were 3 deaths, 2 of which were due to severe head injury from a kick. Helmet use was confirmed in only 12 cases (6%). CONCLUSION: This evaluation of trauma in mounted vs. unmounted equestrians indicates different patterns of injury, contributing to the growing body of literature in this field. We find interaction with horses to be dangerous to both mounted and unmounted equestrians. Intervention with increased safety equipment practice should include helmet usage while on and off the horse.

Crash test rating and likelihood of major thoracoabdominal injury in motor vehicle crashes: the new car assessment program side-impact crash test, 1998-2010.

BACKGROUND: The National Highway Traffic Safety Administration's New Car Assessment Program (NCAP) implemented side-impact crash testing on all new vehicles since 1998 to assess the likelihood of major thoracoabdominal injuries during a side-impact crash. Higher crash test rating is intended to indicate a safer car, but the real-world applicability of these ratings is unknown. Our objective was to determine the relationship between a vehicle's NCAP side-impact crash test rating and the risk of major thoracoabdominal injury among the vehicle's occupants in real-world side-impact motor vehicle crashes. METHODS: The National Automotive Sampling System Crashworthiness Data System contains detailed crash and injury data in a sample of major crashes in the United States. For model years 1998 to 2010 and crash years 1999 to 2010, 68,124 occupants were identified in the Crashworthiness Data System database. Because 47% of cases were missing crash severity (ΔV), multiple imputation was used to estimate the missing values. The primary predictor of interest was the occupant vehicle's NCAP side-impact crash test rating, and the outcome of interest was the presence of major (Abbreviated Injury Scale [AIS] score ≥ 3) thoracoabdominal injury. RESULTS: In multivariate analysis, increasing NCAP crash test rating was associated with lower likelihood of major thoracoabdominal injury at high (odds ratio [OR], 0.8; 95% confidence interval [CI], 0.7-0.9; p < 0.01) and medium (OR, 0.9; 95% CI, 0.8-1.0; p < 0.05) crash severity (ΔV), but not at low ΔV (OR, 0.95; 95% CI, 0.8-1.2; p = 0.55). In our model, older age and absence of seat belt use were associated with greater likelihood of major thoracoabdominal injury at low and medium ΔV (p < 0.001), but not at high ΔV (p ≥ 0.09). CONCLUSION: Among adults in model year 1998 to 2010 vehicles involved in medium and high severity motor vehicle crashes, a higher NCAP side-impact crash test rating is associated with a lower likelihood of major thoracoabdominal trauma. LEVEL OF EVIDENCE: Epidemiologic study, level III.