Estimates of motor vehicle seat belt effectiveness and use: implications for occupant crash protection

Estimates of the effectiveness of seat belts, when used, in reducing motor vehicle occupant deaths vary widely. A recently publicized claim by one analyst that seat belts reduce vehicle occupant deaths 70-80 per cent is based on studies found to contain fundamental systematic error. Deaths occur only 50 per cent less often to belted compared to nonbelted vehicle occupants in crashes, according to previously unanalyzed data from three U.S. states during recent years. New belt systems would be about 60 per cent effective with 100 per cent use. But surveys of observed belt use in 1975 U.S. cars indicate that two-thirds of drivers were not using belts. Prospects for widespread adoption and enforcement of belt use laws in the U.S. are not encouraging. Substantial reductions in fatal and other injuries would result from the adoption of requirements mandating automatic (passive) protection for front seat occupants in crashes with forward decelerations.     

The "seat belt mark" sign: a call for increased vigilance among physicians treating victims of motor vehicle accidents

The light-induced phase-resetting response of the locomotor activity rhythm in the field mouse Mus booduga was studied at two phases of the circadian cycle known to respond to light stimuli of 15 min duration and 1000 lux intensity with maximum advance (at circadian time 20 [CT20]) and maximum delay phase-shifts (at CT15). The phase-shifts evoked by natural daylight stimuli of various illuminations ranging between 0.001 lux and 10,000 lux and lasting 15 min were estimated. The results clearly demonstrate that the relationship between the phase-shifts and the intensities of light stimuli is nonlinear. Furthermore, a single light stimulus of 0.001 lux, or 0.1 lux intensity for a duration of 15 min, administered at CT20, evoked unequivocal responses; phase delays were observed instead of phase advances. The critical intensities needed for light stimuli of 15 min duration to induce saturating response were calculated and were found to be about 100 lux for CT20 and about 500 lux for CT15. These results suggest that a greater intensity of light is required at the phase CT15 to induce a saturating phase shift than is required at a later phase of the circadian cycle (CT20).     

Patterns of injury in belted and unbelted individuals presenting to a trauma center after motor vehicle crash: seat belt syndrome revisited

STUDY OBJECTIVE: Investigators have described a "seat belt syndrome" consisting variously of injuries to the lumbar or cervical spine, abdominal contents, or all 3. In this study we sought to identify these and any other patterns of injury associated with seat belt use in patients who presented to a trauma center after a motor vehicle crash. METHODS: The charts of all patients involved in motor vehicle crashes who presented as trauma alerts to the study institution between January 1, 1991, and December 31, 1993, were retrospectively reviewed for data regarding belt use and 35 specific injuries in 7 body regions. We calculated the positive likelihood ratio of injury between belted and unbelted patients, along with 95% confidence intervals. RESULTS: We identified 1,124 patients involved in motor vehicle crashes. Of these subjects, 376 were belted and 544 unbelted; in 204 belt status was unknown. Belted patients were more likely to have sustained sternal fracture than were unbelted patients (4% versus .7%; positive likelihood ratio, 1.97; 95% confidence interval, 1.09 to 3.29) but were less likely to have sustained head injury (30.6% versus 46.0%; positive likelihood ratio, .67; 95% confidence interval, .53 to .83). We noted no statistically significant differences in the rates of other specific injuries, including cervical and lumbar fractures and the need for abdominal surgery. CONCLUSION: Severe injuries of all types occur in both belted and unbelted individuals involved in motor vehicle crashes who present to a typical trauma center. With the exception of sternal fractures, injuries previously associated with the seat belt syndrome occurred in similar proportions of belted and unbelted patients. Head injuries were less frequent. Seat belt use cannot serve as a discriminator for specific injury. A diligent search of all body regions is indicated in both belted and unbelted patients.     

Legislation and the prediction of reported seat belt use.

Examined differences between jurisdictions with seat belt use laws and jurisdictions without such laws in the relative importance of factors that influence reported seat belt use. 2,047 Canadians, aged 16 yrs and older, were interviewed personally about their attitudes toward and use of seat belts. Multiple regression analyses performed separately for Ss in the 2 types of jurisdiction revealed that, for both groups, the major predictors of reported seat belt use (past and intended) were attitudes toward seat belt use, normative pressure from friends and family to wear belts, and favorability toward seat belt use laws. Up to 53% of the variance in reported seat belt use was accounted for by these factors and the presence of a seat belt law. Implications for public education programs to promote seat belt use are discussed. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obstructive intestinal herniation due to improper use of a seat belt: a case report

The term "seat belt syndrome" has been used to describe injuries to the abdominal viscera caused by seat belts during car accidents. These injuries are usually sustained as a result of the rapid deceleration that occurs in front-end collisions, with the consequent compression of the abdominal viscera. The spectrum of injuries includes intestinal perforation or stenosis, mesenteric disruption, and lumbar fracture-dislocation. We present an uncommon case of obstructive herniation in a 2-year-old girl which we believe was due to improper use of a seat belt.     

Assessment and treatment of posttraumatic stress disorder after a motor vehicle collision: Empirical findings and clinical observations.

Individuals who experience a serious motor vehicle accident (MVA) are at increased risk for psychological problems, particularly posttraumatic stress disorder (PTSD). In this article, we review the literature on PTSD among MVA survivors, with particular attention to available instruments to screen for and assess symptomatology of the disorder. Approaches to the treatment of PTSD in this population are reviewed, separated into interventions designed to prevent PTSD in unselected samples, treatment targeting individuals with acute stress disorder that is designed to prevent subsequent development of PTSD, and therapy for individuals with chronic PTSD. Treatment process issues are discussed in an effort to integrate empirical findings with clinical observations. The empirical literature suggests several approaches to treatment that have good potential outcomes, although continued work is needed to identify factors that predict treatment response as well as augment individual-based treatment formats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nonsanction seat belt law enforcement: a modern day tale of two cities

This paper describes the implementation and evaluation of a nonsanction seat belt law enforcement program in two experimental communities of contrasting size in a state with a mandatory belt law. The main ingredients of the program were seat belt "salutes," public information and education, and limited use of inexpensive economic incentives. Driver shoulder belt use data collected before, during, and after the experimental programs, compared to similar data collected in a comparison community, showed the approach to be effective. While standard seat belt enforcement activities without incentives have been shown to be effective, many police departments, especially in smaller communities, are reluctant to make wholesale increases in seat belt citations. Although requiring some additional level of manpower and resources, a nonsanction approach to seat belt law enforcement can provide an alternate way of increasing belt use in these communities.     

Absence of the superior labial frenulum in holoprosencephaly: a new diagnostic sign

The upper lip of 17 consecutive individuals with various forms of holoprosencephaly were examined either at autopsy or during clinical evaluation. A total of 88% of cases were missing the superior labial frenulum regardless of the severity of holoprosencephaly or other associated craniofacial defects. Because the frenulum was found to be missing across a complete clinical spectrum of holoprosencephaly including cases exhibiting only minimal craniofacial features, it should be inspected as part of the craniofacial examination, and its absence should be prompt imaging studies of the brain. Absence of the frenulum in holoprosencephaly also provides evidence that its embryonic origin is that of the medial nasal process.     

Rupture of the bowel due to road trauma: the emergence of the "seat belt syndrome"

Seat belts have proved to be life saving for drivers and passengers involved in motor-car collisions. The number of severe head, face and trunk injuries has been significantly reduced. However, the wearing of belts has been responsible for an increased incidence of bowel rupture, in itself a potentially lethal injury if not diagnosed and treated early. There is still much to be done in improving seat belt design.     

Prospective countywide evaluation of the effects of motor vehicle safety device use on hospital resource use and injury severity

Stress echocardiography is increasingly used for the assessment of coronary artery disease and is valuable in the treatment of patients with known disease as well. Although several studies are available on the accuracy of stress echocardiography in the detection of coronary artery disease and evaluation of its severity, studies on the use of this technique for evaluation of prognosis are just now emerging. Over the past decade, few studies have investigated its prognostic value in different patient populations. The versatility and advantage of stress echocardiography lie in the fact that it provides information on both resting ventricular function and stress-induced ischemia, two important determinants of cardiac events. Exercise echocardiography with the bicycle or posttreadmill approach is used in subjects who can exercise and provides important additional prognostic data from physiologic exercise variables. In patients unable to exercise, pharmacologic stress echocardiography with dobutamine or vasodilators is used. Stress echocardiography has been shown to identify different populations of patients at risk of cardiac events, including those with stable or suspected coronary artery disease, those with acute myocardial infarction, and those scheduled for major noncardiac surgery. In the early postinfarct setting, exercise and vasodilator stress have been used more often, whereas dobutamine echocardiography has been used predominantly at low doses for the assessment of residual myocardial viability. This review focuses on recently published investigations evaluating the prognostic effect of stress echocardiography in patients with stable coronary artery disease or acute myocardial infarction.     

Psychiatric morbidity following motor vehicle accidents: a review of methodological issues

Motor vehicle accidents (MVAs), even those of a nonserious nature, appear to increase the risk of severe psychiatric morbidity in survivors. The present review examines the evidence indicating the levels of psychiatric morbidity in MVA survivors. Although no consistent profile has emerged, the most commonly reported symptoms are depression, anxiety, irritability, driving phobia, anger, sleep disturbances, and headache, with rates of posttraumatic stress disorder (PTSD) across studies of 0% to 100%. Variability in the type and severity of psychiatric outcomes may be due, in part, to methodological inadequacies in many studies, particularly the use of biased population samples, inclusion of subjects exposed to varied types of accidents, an absence of a clear definition of PTSD, a reliance on clinical judgment rather than the use of objective psychometric measures, the failure to include ratings of injury severity, and the absence of assessments for past exposure to traumatic events or preexisting posttraumatic reactions. The most important concern relates to the use of nonrepresentative samples, usually patients referred for medicolegal assessment in whom issues of compensation are of central importance. Gender and age differences distinguish the compensation group from the general population of MVA survivors, who therefore may also differ in the vulnerability to posttraumatic morbidity. It is argued that more systematic research on unselected subject samples is critical to establish epidemiological data on the true nature and extent of psychiatric morbidity following MVAs.     

Injury pattern and severity in lateral motor vehicle collisions: a Canadian experience

OBJECTIVE: To determine the pattern and severity of injury and the outcome of front seat motor vehicle occupants after lateral impact crashes. DESIGN: Retrospective review undertaken in a Regional Trauma Unit (Sunnybrook Health Science Centre). MATERIALS AND METHODS: Review of seriously injured front seat motor vehicle occupants admitted to a Regional Trauma Unit over a 46-month period (September 15, 1989, to July 15, 1993) for whom vehicle crash information and occupant seat belt use were known. MEASUREMENTS AND MAIN RESULTS: Three hundred forty-eight front seat vehicle occupants were available for study; one hundred forty-one (41%) were involved in a lateral impact motor vehicle crash. Driver side lateral crashes (57%) were more common than passenger side impacts. Victims of lateral impact crashes had a significantly higher mean Injury Severity Score (25 compared with 20 for nonlateral crashes: p < 0.05), and the direction of impact was strongly associated with injury severity (p < 0.05). Lateral impact crashes resulted in substantially more significant chest (p < 0.01) and intra-abdominal (p < 0.0001) injuries. Type of injury was significantly different between the lateral and nonlateral impact groups for facial, chest, abdominal, and musculoskeletal injuries. CONCLUSIONS: The direction of impact in motor vehicle crashes is strongly associated with the pattern and severity of organ injuries. Further attention to automobile safety design is necessary to better protect occupants involved in lateral impact crashes.     

Impact of diagnostic laparoscopy in the management of the unilateral impalpable testis

OBJECTIVE: To evaluate the impact of laparoscopy on the management of children with a unilateral impalpable testis. PATIENTS AND METHODS: The study population consisted of 27 children who underwent a primary inguinal exploration for a unilateral impalpable testis. RESULTS: Twelve of 27 (44%) children had inguinal or 'peeping' testes and 10 of 27 (37%) had blind-ending vasa and vessels in the inguinal canal; four of these 10 had atrophic tubular tissue in the excised remant. Four of 27 (15%) had blind-ending vasa and vessels proximal to the internal ring. Only one child had a testis proximal to the internal ring. Only the four children (15%) with blind-ending vasa and vessels proximal to the internal ring would have benefited from a laparoscopy by avoiding an inguinal exploration. CONCLUSIONS: Because of the time, expense and limited usefulness of laparoscopy in altering the management of children with a unilateral unpalpable testis, we reserve laparoscopy for cases where inguinal exploration has failed.     

Safety belt restraints and compartment intrusions in frontal and lateral motor vehicle crashes: mechanisms of injuries, complications, and acute care costs

A 3-year prospective study examined 76 frontal (F) and 45 lateral (L) motor vehicle crash (MVC) patients with regard to seatbelt restraint use and occupant compartment contact and intrusion injuries. These 121 MVC victims with multiple injuries (39 belted [B] and 82 non-belted [NB]), admitted to a level I trauma center, were studied by accident reconstruction and medical data analysis. They had a MVC mean impact velocity (delta V) of 30 +/- 11 mph and an injury Severity Score of 29 +/- 12. Proper restraint use reduced brain injury in F MVCs (30% FB vs. 47% FNB) but had no effect in L MVCs (63% LB vs. 30% FB [p < 0.06]). Belt use did not protect against lung, liver, spleen, pelvis, or lower extremity (LE) injury. These appeared to be more a function of crash direction, with LE injuries higher in F crashes (p < 0.04) and pelvis injuries (p < 0.001) higher in L crashes. In FB crashes, however, properly used safety restraints were the primary cause of bowel or colon injuries (p < 0.006). Belts did not prevent thoracic or abdominal solid organ injuries in L crashes. Contact-intrusions (CI) of the car occupant compartment in F crashes were the main cause of brain (A-pillar), lung and liver (steering wheel and instrument panel), and LE (toepan) injuries; but in L crashes, side-door CI caused lung, aorta, liver, and pelvic injuries. In contrast, contact-only (CO) injuries of the steering assembly were mainly responsible for injuries to the lung, heart, and liver in F crashes, and side-door CO for lung, liver, and spleen injuries in L crashes. Deaths and complications after injury were higher among F MVC occupants, or when delta V was > or = 30 mph. Hospital and professional costs reflect the complex care needed for victims of multiple injuries: FB, $99,000; FNB, $95,000; LB, $75,000; LNB, $79,000; total, $10.7 million. Present vehicle safety standards are not adequate, and structural design changes are needed to improve restraints and protect occupants from intrusion-related injuries.     

Repetitive axonal stimulation of the same single motor unit: a longitudinal tracking study

We elicited three single motor unit action potentials (S-MUAPs) via multiple point stimulation and subjected them to repetitive stimulation (RS) in 3 healthy subjects. We tracked each S-MUAP and its RS trains over two separate sessions as well as the compound motor action potential (CMAP) RS trains obtained from the same muscle following whole nerve stimulation. Repetitive axonal stimulation yields consistent results when carefully performed with minimal variation in each S-MUAP RS train from session to session, providing previously unobtainable data regarding neuromuscular junction function in the same single motor unit over time. In this small, normative sample, no significant correlation between S-MUAP and CMAP RS responses was observed.     

Long-term effects of losing a spouse or child in a motor vehicle crash.

Interviews were conducted with 39 individuals who had lost a spouse in a motor vehicle crash 4 to 7 years ago and 39 controls and with 41 parents who had lost a child in a crash and 41 controls. Significant differences between bereaved spouses and controls were revealed on several indicators of general functioning, including depression and other psychiatric symptoms, social functioning, psychological well-being, reactivity to good events, and future worries and concerns. Comparisons between bereaved and control parents also revealed significant differences on some measures of general functioning (especially depression). Responses suggest that the deceased continued to occupy the thoughts and conversations of bereaved spouses and parents. Many respondents continued to ruminate about the accident or what might have been done to prevent it, and they appeared to be unable to accept, resolve, or find any meaning in the loss. Data provide little support for traditional notions of recovery from the sudden, unexpected loss of a spouse or child. (73 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)