Reducing Cardiovascular Disease Risk for Employees Through Participation in a Wellness Program.

The objective was to evaluate the long-term impact that the University of Rochester Employee Wellness program has made in reducing cardiovascular disease risk. The authors conducted a 5-year retrospective study to measure change in health outcomes for more than 16,000 employees who participated in the program for more than 1 year between January 2013 and December 2017. A logistic regression model was applied to estimate the impact of participation on improvement in cardiovascular disease risk. Statistically significant improvement was found in the health of participants. Almost 50% of all program participants, having moderate-to-high risk at baseline, improved their 10-year cardiovascular disease risk. Moreover, about a third of participants improved by a full risk category. Engagement in a condition management program also was found to increase the odds of improvement by 36%. The integrated approach to wellness can improve the long-term health of participants and reduce their risk of developing cardiovascular disease by achieving long-term improved lifestyle behaviors. Employers, employee benefits brokers, and insurance companies need to assess wellness programs by their performance and by their design, specifically as it relates to long-term outcomes.

Prenatal and Infancy Nurse Home Visiting Effects on Mothers: 18-Year Follow-up of a Randomized Trial.

BACKGROUND: Prenatal and infancy home-visiting by nurses is promoted as a means of improving maternal life-course, but evidence of long-term effects is limited. We hypothesized that nurse-visitation would lead to long-term reductions in public-benefit costs, maternal substance abuse and depression, and that cost-savings would be greater for mothers with initially higher psychological resources. METHODS: We conducted an 18-year follow-up of 618 out of 742 low-income, primarily African-American mothers with no previous live births enrolled in an randomized clinical trial of prenatal and infancy home visiting by nurses. We compared nurse-visited and control-group women for public-benefit costs, rates of substance abuse and depression, and examined possible mediators of intervention effects. RESULTS: Nurse-visited women, compared with controls, incurred $17 310 less in public benefit costs (P = .03), an effect more pronounced for women with higher psychological resources ($28 847, P = .01). These savings compare with program costs of $12 578. There were no program effects on substance abuseor depression. Nurse-visited women were more likely to be married from child age 2 through 18 (19.2% vs 14.8%, P = .04), and those with higher psychological resources had 4.64 fewer cumulative years rearing subsequent children after the birth of the first child (P = .03). Pregnancy planning was a significant mediator of program effects on public benefit costs. CONCLUSIONS: Through child age 18, the program reduced public-benefit costs, an effect more pronounced for mothers with higher psychological resources and mediated by subsequent pregnancy planning. There were no effects on maternal substance abuse and depression.

Prenatal and Infancy Nurse Home Visiting and 18-Year Outcomes of a Randomized Trial.

OBJECTIVES: Given earlier effects found in randomized clinical trials of the Nurse-Family Partnership, we examined whether this program would improve 18-year-old first-born youths' cognition, academic achievement, and behavior and whether effects on cognitive-related outcomes would be greater for youth born to mothers with limited psychological resources (LPR) and on arrests and convictions among females. METHODS: We enrolled 742 pregnant, low-income women with no previous live births and randomly assigned them to receive either free transportation for prenatal care plus child development screening and referral (control; n = 514) or prenatal and infant home nurse visit (NV) plus transportation and screening (n = 228). Assessments were completed on 629 18-year-old first-born offspring to evaluate these primary outcomes: (1) cognitive-related abilities (nonverbal intelligence, receptive language, and math achievement) and (2) behavioral health (internalizing behavioral problems, substance use and abuse, sexually transmitted infections, HIV risk, arrests, convictions, and gang membership). RESULTS: Compared with control-group counterparts, NV youth born to mothers with LPR had better receptive language (effect size = 0.24; 95% confidence interval [CI]: 0.00 to 0.47; P = .05), math achievement (effect size = 0.38; 95% CI: 0.14 to 0.61; P = .002), and a number of secondary cognitive-related outcomes. NV females, as a trend, had fewer convictions (incidence ratio = 0.47; 95% CI: 0.20 to 1.11; P = .08). There were no intervention effects on other behaviors. CONCLUSIONS: The program improved the cognitive-related skills of 18-year-olds born to mothers with LPR and, as a trend, reduced female convictions but produced no other effects on youth behavioral health.

Low birthweight in second children after nurse home visiting.

OBJECTIVE: To examine low birthweight and preterm birth of second children born to home-visited first-time mothers. SUBJECTS: Women were previously recruited for a randomized controlled trial of the home visiting model disseminated as Nurse-Family Partnership. 512 of these women had second children within 18 years of the first child's birth, and were included in our sample. RESULTS: The intervention was associated with a lower likelihood of low birthweight for second children (odds ratio: 0.51, 95% CI: 0.27, 0.97), an effect apparent only if the first-born had low birthweight and mediated by close birth spacing. These moderation and mediation patterns were similar in the preterm birth outcome. CONCLUSION: A home visiting program provided for first-born children reduced low birthweight for second-born children, if the first-born had low birthweight. This finding implies a broader impact than previously documented, because few studies have included these second children.

Federally qualified health centers reduce the primary care provider gap in health professional shortage counties.

BACKGROUND: Federally qualified health centers (FQHCs) were designed to provide care in medically underserved areas. Substantial and sustained federal funding has accelerated FQHC growth. PURPOSE: To examine temporal trends in primary care provider supply and whether FQHCs have been successful in reducing the gap in provider supply in primary care health professional shortage areas (HPSAs). METHODS: Retrospective cohort study design using national county-level data from 2009 to 2013. Primary care providers included physicians, nurse practitioners, and physician assistants. FINDINGS: Partial-county HPSAs had the highest average provider supply and the greatest increase, followed by non-HPSA counties and whole-county HPSAs. The provider gap was larger in whole-county HPSAs compared with partial-county HPSAs. Counties with one or more FQHC sites had a smaller provider gap than those without FQHC sites. An increase of one FQHC site was statistically significantly associated with a reduction in the annual provider gap. DISCUSSION: FQHCs reduced the gap in primary care provider supply in shortage counties and mitigated uneven distribution of the primary care workforce.

An Exploration of the Determinants of Gestational Weight Gain in African American Women: Genetic Factors and Energy Expenditure.

BACKGROUND: Excessive gestational weight gain (GWG) has a long-term impact on women's body weight and contributes to the development of obesity in the mother and her child. Many risk factors for GWG have been identified, but to date, only 6-33.8% of the variance in GWG has been explained. The purpose of this study was to evaluate the overall variance of GWG that can be explained by including weight-adjusted resting metabolic rate (aRMR) and a genetic risk score constructed on obesity-related genes in addition to sociodemographic and lifestyle factors. METHODS: In this observational study involving 55 African American women, data collected/measured during pregnancy included sociodemographic factors, medical information, lifestyle factors, aRMR, and seven obesity-related genes. Multivariable linear regression was performed to evaluate the variance in GWG explained by the potential risk factors listed above. RESULTS: The mean GWG was 15 kg (±7.5 kg), and 63.6% of women gained more than the Institute of Medicine's GWG recommendations. The final regression model explained 53.3% of the variance in GWG. Higher genetic risk score, lower aRMR, and higher dietary intake of total energy and percentage of fat were significantly associated with increased GWG ( p < .05). These factors explained 18% additional variance in GWG over that explained by significant sociodemographic and lifestyle factors in the analysis (i.e., maternal age, prepregnancy body mass index, parity, illegal drug use, and education). CONCLUSION: Overall, our results indicate that the genetic risk score, aRMR, and dietary intake have a substantial impact on GWG in African American women.

Effect of Gestational Weight Gain and Prepregnancy Body Mass Index in Adolescent Mothers on Weight and Body Mass Index of Adolescent Offspring.

PURPOSE: The purpose of the study was to examine the association of the gestational weight gain and prepregnancy body mass index (BMI) of low-income adolescent mothers with the risk of their children being overweight and/or obese in late adolescence. METHODS: Study subjects were low-income, primiparous adolescents (n = 360) who self-identified as black and participated in the New Mothers Study in Memphis, Tennessee, and their children. Gestational weight gain was examined as a continuous variable and also categorized into overgain, recommended gain, and undergain following the 2009 Institute of Medicine guidelines. The effects of maternal prepregnancy BMI percentiles and calculated BMI were also considered. Multivariable logistic and linear regression models were used. The main outcome measures were offspring overweight, obesity, and BMI. RESULTS: Thirty-nine percent of offspring were overweight or obese. Higher maternal gestational weight gain increased the risk for offspring overweight and obesity. There was an interaction between gestational weight gain and prepregnancy BMI: offspring of mothers with a BMI percentile ≤76 were at greater risk of obesity with higher maternal weight gain. If mothers with a BMI percentile between the 29th and 83rd percentiles overgained, offspring were at greater risk for overweight. Using calculated BMIs, if a mother's BMI was ≤26 kg/m2, offspring risk for obesity was greater with higher gestational weight gain. CONCLUSIONS: High gestational weight gain had a larger effect on offspring overweight and obesity if maternal prepregnancy BMI percentile was ≤76. The gestational weight gain of primiparous adolescents who self-identified as black had an effect on offspring weight.

Differences in opioid prescribing in low back pain patients with and without depression: a cross-sectional study of a national sample from the United States.

INTRODUCTION: Low back pain (LBP) is among the leading indications for the prescription of opioid analgesics in clinical practice. There is increasing evidence suggesting that these agents may have diminished efficacy in the treatment of LBP. OBJECTIVES: We evaluated the relationship between depression, the probability of receiving an opioid prescription, and the amount of morphine equivalent amounts prescribed per year among patients with LBP using nationwide data. METHODS: A cross-sectional analysis was performed on existing data from the Medical Expenditure Panel Survey data set from the period 2004 to 2009. Demographic, medical condition, Patient Health Questionnaire-2 responses, and prescription drug information were obtained on 56,811,864 weighted person-years of data from individuals aged 18 to 65 with an ICD-9 code specific to LBP. RESULTS: Increases in PHQ-2 score, as well a positive screen for depression, were associated with an increased probability of being prescribed opioid therapy and more morphine equivalents per year. CONCLUSION: Analysis of a nationwide sample of patients with LBP shows an association between depression and higher rates of opioid prescribing after controlling for several known cofounders. Clinicians prescribing opioids in LBP populations that rely on clinical trial results that exclude depressed patients may misjudge the risks and benefits of this class of therapy.

A Prospective Cohort Study of Influences on Externalizing Behaviors Across Childhood: Results From a Nurse Home Visiting Randomized Controlled Trial.

OBJECTIVE: This study investigated genetic and environmental influences on behavior in a cohort of 600 children followed prenatally to 18 years. METHOD: A randomized controlled trial of prenatal/infancy nurse home visits (NHV) was conducted in 600 predominantly African American mothers and their firstborn children from Memphis, TN. Mothers were assessed in pregnancy for mental health (MH), self-efficacy, and mastery. Mothers reported longitudinally on smoking and alcohol/drug use. The functional polymorphisms SLC6A4 5-HTTLPR, FKBP5 rs1360780 and DRD2/ANKK1 rs1800497 were genotyped together with 186 ancestry informative markers. Composite externalizing disorders (ED) continuous total scores from the mother-report Achenbach Child Behavior Checklist were included as dependent variables in regression analyses for time points 2, 6, 12, and 18 years. RESULTS: Behaviors at younger ages strongly predicted later behaviors (p < .0001). Children whose mothers had high self-efficacy and had received NHV were better behaved at age 2 years. Poorer maternal MH adversely influenced ED up to 12 years, but at age 18 years, maternal mastery exerted a strong, positive effect (p = .0001). Maternal smoking was associated with worse ED at 6 and 18 years. Main and interactive effects of genetic polymorphisms varied across childhood: FKBP5 rs1360780 up to age 6, 5-HTTLPR from 6 to 12, and DRD2/ANKK1 rs1800497 from 2 to 18 years. CONCLUSION: Our study suggests that maternal MH and resilience measured in pregnancy have long-lasting effects on child behavior. Maternal smoking across childhood and genetic factors also play a role. NHV had a positive effect on early behavior. Our findings have implications for prevention of pathological behaviors in adulthood. Clinical trial registration information-Age-17 Follow-Up of Home Visiting Intervention; http://clinicaltrials.gov/; NCT00708695.

Effect of home visiting by nurses on maternal and child mortality: results of a 2-decade follow-up of a randomized clinical trial.

IMPORTANCE: Mothers and children living in adverse contexts are at risk of premature death. OBJECTIVE: To determine the effect of prenatal and infant/toddler nurse home visiting on maternal and child mortality during a 2-decade period (1990-2011). DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical trial was designed originally to assess the home visiting program's effect on pregnancy outcomes and maternal and child health through child age 2 years. The study was conducted in a public system of obstetric and pediatric care in Memphis, Tennessee. Participants included primarily African American women and their first live-born children living in highly disadvantaged urban neighborhoods, who were assigned to 1 of 4 treatment groups: treatment 1 (transportation for prenatal care [n = 166]), treatment 2 (transportation plus developmental screening for infants and toddlers [n = 514]), treatment 3 (transportation plus prenatal/postpartum home visiting [n = 230]), and treatment 4 (transportation, screening, and prenatal, postpartum, and infant/toddler home visiting [n = 228]). Treatments 1 and 3 were included originally to increase statistical power for testing pregnancy outcomes. For determining mortality, background information was available for all 1138 mothers assigned to all 4 treatments and all but 2 live-born children in treatments 2 and 4 (n = 704). Inclusion of children in treatments 1 and 3 was not possible because background information was missing on too many children. INTERVENTIONS: Nurses sought to improve the outcomes of pregnancy, children's health and development, and mothers' health and life-course with home visits beginning during pregnancy and continuing through child age 2 years. MAIN OUTCOMES AND MEASURES: All-cause mortality in mothers and preventable-cause mortality in children (sudden infant death syndrome, unintentional injury, and homicide) derived from the National Death Index. RESULTS: The mean (SE) 21-year maternal all-cause mortality rate was 3.7% (0.74%) in the combined control group (treatments 1 and 2), 0.4% (0.43%) in treatment 3, and 2.2% (0.97%) in treatment 4. The survival contrast of treatments 1 and 2 combined with treatment 3 was significant (P = .007); the contrast of treatments 1 and 2 combined with treatment 4 was not significant (P = .19), and the contrast of treatments 1 and 2 combined with treatments 3 and 4 combined was significant (post hoc P = .008). At child age 20 years, the preventable-cause child mortality rate was 1.6% (0.57%) in treatment 2 and 0.0% (SE not calculable) in treatment 4; the survival contrast was significant (P = .04). CONCLUSIONS AND RELEVANCE: Prenatal and infant/toddler home visitation by nurses is a promising means of reducing all-cause mortality among mothers and preventable-cause mortality in their first-born children living in highly disadvantaged settings. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00708695.

Randomized controlled trial of CARE: an intervention to improve outcomes of hospitalized elders and family caregivers.

In this randomized controlled trial we tested the efficacy of an intervention program (CARE: Creating Avenues for Relative Empowerment) for improving outcomes of hospitalized older adults and their family caregivers (FCGs). FCG-patient dyads (n = 407) were randomized into two groups. The CARE group received a two-session empowerment-educational program 1-2 days post-admission and 1-3 days pre-discharge. The attention control group received a generic information program during the same timeframe. Follow-up was at 2 weeks and 2 months post-discharge. There were no statistically significant differences in patient or FCG outcomes. However, inconsistent evidence of role outcome differences suggests that CARE may benefit certain FCG subgroups instead of being a one-size-fits-all intervention strategy. Closer examination of CARE's mechanisms and effects is needed.

Internet recruitment and retention for a 6 months' longitudinal study.

PURPOSE: To examine factors influencing recruitment and retention of study participants in a longitudinal study. METHODS: After completion of a longitudinal (6 months) study of long-term indwelling urinary catheter users, three types of data were analyzed: number of problems with data entry into an online survey, number of reminders sent by study staff to participants, and number and nature of e-mail contacts between participants and study staff and among study staff regarding the study. CONCLUSIONS: The Internet can be used effectively for research, especially involving small, specialized populations. In order to retain study subjects and obtain complete and accurate data, study staff must be closely involved and responsive to participants' issues, and technical support staff must be readily available and invested in the research project. CLINICAL RELEVANCE: Using the Internet to reach small, special, marginalized, or geographically dispersed populations for research is becoming common. Researchers need to know how best to recruit, support, and retain participants in Internet-based studies.

Finite element aortic injury reconstruction of near side lateral impacts using real world crash data.

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes, only less prevalent than brain injury. On average, nearly 8000 people die annually in the United States due to blunt injury to the aorta. It is observed that over 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. In the current study, eight near side lateral impacts, in which TRA occurred, were reconstructed using a combination of real world crash data reported in the Crash Injury Research and Engineering Network (CIREN) database, finite element (FE) models of vehicles, and the Wayne State Human Body Model - II (WSHBM). For the eight CIREN cases reconstructed, the high strain regions in the aorta closely matched with the autopsy data provided. The peak average maximum principal strains in all of the eight CIREN cases were localized in the isthmus region of the aorta, distal to the left subclavian artery, and averaged at 22 ± 6.2% while the average maximum pressure in the aorta was found to be 117 ± 14.7 kPa.

Analysis of the mechanism of lateral impact aortic isthmus disruption in real-life motor vehicle crashes using a computer-based finite element numeric model: with simulation of prevention strategies.

INTRODUCTION: Despite advances in the surgical therapy of aortic injury (AI) using endovascular prostheses, more than 60% of motor vehicle crash (MVC) induced AIs die at the scene. In 80 cases of MVC AI, both change in velocity on impact (Delta V) and impact energy (IE) were correlated with autopsy or surgical findings. Of the 34 AIs due to lateral impact MVCs (LMVC), 91% had an aortic isthmus laceration. Computer simulation is used to study the cause of LMVC AI. METHODS: To delineate AI mechanism, 10 real life LMVCs (8 left, 2 right) were simulated using a computer-based finite element numerical model. Each began with the initial vehicle impact with another vehicle or fixed object, followed by the vehicle's compartment structures' impact with the patient's chest wall, causing a rise in intra-aortic pressure and the resulting location and pattern of aortic wall stresses and strains. In the real LMVCs, the Delta V ranged from 27.5 to 62 kph with impact energies of from 46,051 to 313,502 joules. In both real-life and the model, the main cause of the chest wall impact was intrusion of the car's B-pillar. Dynamic simulations delineate increased stress and strains at the aortic Isthmus. In some LMVCs, the B-pillar intrusion was also seen to impact the head in the AI cases. RESULTS: In the simulations, aortic pressure rose from 100 mm Hg precrash to as high as 1,322 mm Hg. Both the maximum aortic longitudinal tensile strain and the von Mises Stress were proportional to the maximum force impacted on the chest wall. Aortic isthmus maximum stresses ranged from 1.1 Mega Pascal (MPa) to 3.2 MPa, with longitudinal tensile strains ranging from 8.2% to 48.5%. The simulation dynamics demonstrated that the proximal pressurized turgid aorta initially moves toward the LMVC impact. As a result, the ascending aorta and aortic arch (proximal ascending aorta) rotate about the fulcrum of the great vessels, so that this aortic unit, acting as the long-arm of an Archimedes lever system, exerts the maximum stress and strain at the aortic isthmus or short-arm, where the real-life aortic rupture occurs. CONCLUSION: Simulation supports the lever hypothesis that the force on the short-arm aortic isthmus is proportionally greater than at the long-arm proximal aorta. Simulation also suggests improved vehicle construction techniques, which increase the strength and resistance to deformation of the B-pillar and vehicle side structure plus a B-pillar airbag will limit the intrusion forces causing LMVC AIs and reduce the incidence of associated head injuries.

Study on the use of long-term urinary catheters in community-dwelling individuals.

PURPOSE: The purpose of this study was to determine the incidence and distribution of catheter-related problems in long-term indwelling urinary catheter users. We also sought to assess appropriateness of catheter use and examine relationships among catheter complications and catheter care practices. DESIGN: This repeated-measures study involved self-reported data collection by recall at intake and by prospective data collection at 2, 4, and 6 months in long-term urinary catheter users. SUBJECTS AND SETTING: Two sampling arms were used: a home care (HC) agency with 10 individuals and the Internet with 33 people having spinal cord injury. METHODS: Home visit and follow-up telephone call interviews were used with the participants from the HC agency. Data were self-administered through SurveyMonkey in the Internet sample, and communication was through e-mail, telephone, and postal mail. Analysis included descriptive statistics and generalized estimating equation techniques to adjust for within-subject variation over time. RESULTS: All study participants had at least 1 catheter-related problem during 8 months, and many had multiple, recurring problems. Catheter-associated urinary tract infection (CAUTI) was reported by 70%, blockage by 74%, leakage by 79%, and accidental dislodgement by 33%. Key tests of associations (generalized estimating equation) predicted that catheter size contributed to CAUTI, with significant covariates of female gender and younger age. The presence of sediment in the urine on the day of the survey predicted catheter blockage. CONCLUSION: The incidence of all complications was higher than expected. Problems associated with long-term indwelling catheter use may contribute to excess healthcare utilization adversely affecting both users and their families.

Computer simulation and validation of the Archimedes Lever hypothesis as a mechanism for aortic isthmus disruption in a case of lateral impact motor vehicle crash: a Crash Injury Research Engineering Network (CIREN) study.

OBJECTIVES: Can aortic isthmus disruption occurring in a lateral motor vehicle crash (LMVC) be explained by the Archimedes Lever Hypothesis, where the intrathoracic aorta, super-pressurized by the thoracic impact force, functions as a rigid lever system? The long arm of this lever system is the proximal aorta-aortic arch, the short arm is the aortic isthmus fixed distally at the descending aorta, and the fulcrum is at the great vessels, especially the left subclavian artery. METHODS: The theory was tested by a simulation technique using a computer-based finite element numerical model system. This simulation model included the dynamics of the crashed vehicles, the direction of force impact, and the structure of the thorax and intrathoracic viscera, including the entire intrathoracic aorta. The specific patient whose data were entered into the model was chosen from a study of 34 LMCV aortic injuries (AIs). The model was constrained by patient and vehicle data from this surviving case. RESULTS: Three sequential lateral thoracic levels impacted by the vehicle side structures were selected. At each level, the maximum mean intra-aortic pressure was 50 to 100 ms after impact, the structure dynamics of the actual crash and the resultant vehicle deformation were simulated; only when the lateral impact was induced in a transverse plane including the first 4 ribs at the level of the aortic arch/isthmus system, with intra-aortic pressures from 200 to 500 mm Hg, were AI-compatible stresses and deformations in the aortic wall achieved at the isthmus. CONCLUSIONS: In LMVC AI, the simulation suggests that the aorta functions as an Archimedes Lever System in which the magnified force mediated by the long lever arm produces sufficient strain on the short lever arm to rupture the aorta at the isthmus.

Spine and spinal cord injury in motor vehicle crashes: a function of change in velocity and energy dissipation on impact with respect to the direction of crash.

OBJECTIVE: To examine the effect of change in velocity (DeltaV) and energy dissipation (IE) on impact, above and below the test levels for Federal MVC Safety Standards, on the incidence of spine fractures (SF), spinal cord injury (SCI)), SF mortality and the associated injury patterns in Frontal (F) and Lateral (L) MVCs. Comparison of 214 patients with SF or SCI with 938 patients who did not have SF or SCI. METHODS: 1152 MVC adult drivers or front-seat passengers (701 F & 451 L) evaluated at 10 Level I CIREN study Trauma Centers together with vehicle and crash scene engineering reconstruction. Patient seat belt (SB) and/or airbag (AB) use correlated with clinical, or autopsy findings. RESULTS: The relationship between DeltaV and IE rose exponentially as DeltaV increased. Of the 1152 patients, all with AIS> or =3 injuries, there were 214 patients with spine fractures of AIS > or =2. In FMVCs there were more SF patients with Cervical SF than in LMVCs (68F versus 64 L) and more Thoracic (35F versus 21L) and Lumbar (39F versus 16L) SF. However, the incidence of spinal cord injury was greatest in the Cervical SF (33%), compared with the Thoracic SF (18%), or Lumbar SF (2%). Most important, in FMVCs 49% of SF, 47% of SCI and 71% of the SF deaths (p < 0.05) occurred at > mean of 47.4 kph. In contrast, in LMVCs 51% of SF, 52% of SCI and 67% of the SF deaths occurred at DeltaV > mean of 35.3 kph. However, 80% of all deaths in SCI occurred in Cervical SF cases, in these 74% also had a brain injury. In contrast, the deaths in Thoracic SF were due to combinations of brain (45%), thorax (95%) or associated pelvic fracture injuries (50%). Airbag (AB), or Seat belt (SB) restraints appeared to protect FMVC SF patients from SCI at lower DeltaV, but 84% of Cervical SCI patients at DeltaV > 47 kph had AB protection and in a few cases the AB appeared responsible for the SCI. In contrast, 82% of Lumbar SF patients had SB, but in FMVCs where jackknifing due to backloading occurred, improper SB positioning may have contributed to the SF. CONCLUSIONS: The implication for SCI in both front seat drivers and passengers in either FMVC or LMVC crashes above their respective DeltaV means is that improved spine fracture protection is necessary at higher DeltaV levels. More effective safety systems to prevent Cervical SCIs should be developed using two-level frontal and side AB & SB+pretensioner devices, which protect against SF at DeltaV both at and 1SD above the FMVC (47 & 72 kph = 30 & 45 mph) and LMVC (35 & 54 kph =22 & 34 mph) means.

Change in velocity and energy dissipation on impact in motor vehicle crashes as a function of the direction of crash: key factors in the production of thoracic aortic injuries, their pattern of associated injuries and patient survival. A Crash Injury Research Engineering Network (CIREN) study.

OBJECTIVE: To examine the effect of change in velocity (MV) and energy dissipation (IE) on impact, above and below the test levels for federal motor vehicle crash (MVC) safety standards, on the incidence of aortic injury (AI) and its mortality and associated injury patterns in frontal (F) and lateral (L) MVCs. Comparison of 80 AI and 796 non-AI patients of AIS=3. METHODS: Eight hundred seventy-six MVC adult drivers or front-seat passengers (552 F and 324 L) evaluated by 10 Level I CIREN study Trauma Centers together with vehicle and crash scene engineering reconstruction. Patient seatbelt and/or airbag use correlated with clinical or autopsy findings. RESULTS: In AI, 63% of cases were dead at the scene and only 16% survived to leave hospital. The relation between IE dissipated in the MVC and the DeltaV on impact was exponential as DeltaV increased, but the rise in IE for a given DeltaV was greater in LMVC than in FMVC (p <0.05). A more rapid rise in IE/DeltaV occurred above the mean DeltaV of 48 +/- 19.7 kph (30 mph) in FMVC and above the mean DeltaV of 36 +/- 16.2 kph (23 mph) in LMVC. As DeltaV increased above these means, 65% of 46 FMVC aortic injuries (AIs) and 64% of 34 LMVC AIs occurred. In AI patients there was evidence of focusing of the point of IE impact on the upper chest with a higher incidence of rib1-4 fractures than in non-AI (p <0.01) and more brain, heart, lung and spleen injuries (p <0.01) consequent to lower seatbelt use (p <0.01), but LMVC also had more pelvic fx (p <0.05). Airbags + seatbelts in FMVC and seatbelts in LMVC reduced mortality (p <0.05) Comparison of AI incidence in three successive 4-year vehicle model year periods showed a progressive decrease as new safety devices were introduced (p < 0.05). CONCLUSIONS: The implications for AI of the focused IE at the upper chest suggest a probable mechanism for MVC AI with the pressurized aortic arch acting as the long arm of a lever system with the fulcrum at the subclavian artery, producing maximum torsional strain at the short arm of the isthmus where 75% of the AIs occurred. AI mortality is also influenced by the associated injuries. To develop more effective safety systems to prevent AI, MVC safety testing with airbags and seatbelts should be carried out at DeltaVs of 1 SD above means for FMVC and LMVC.

Oxygen debt criteria quantify the effectiveness of early partial resuscitation after hypovolemic hemorrhagic shock.

BACKGROUND: The effectiveness of partial resuscitation after hypovolemic hemorrhagic shock with deferment of full resuscitation is critical to successful hypotensive resuscitation. METHODS: To quantitatively address this issue, 40 canines were bled under anesthesia to a mean oxygen debt (O(2)D) of 104 +/- 7.6 mL/kg over 60 minutes (mortality, 40%). Animals surviving the shock were then immediately resuscitated with 0%, 8.4%, 15%, 30%, or 120% (full resuscitation) of shed volume as 5% albumin and held for 2 hours postshock, when the remaining portion of full resuscitation volume was given. Animals were followed for 7 days postshock with hepatic and renal function studies, and then, under anesthesia, cardiac output and organ biopsy specimens were taken before the animals were killed. RESULTS: By 2 hours postshock, 0% immediate resuscitation had an O(2)D increase of 80 mL/kg above end of shock, but O(2)D at 8.4% immediate resuscitation decreased -30 mL/kg, 15% immediate resuscitation fell -65 mL/kg, 30% immediate resuscitation decreased -80 mL/kg below end of shock, and O(2)D with 120% full resuscitation fell to preshock levels. All decreases in O(2)D were significantly (p < 0.05) below end of shock, but both 15% and 30% immediate resuscitation exceeded the 8.4% immediate resuscitation rate (p < 0.05) throughout the resuscitation, and 120% full resuscitation exceeded these (p < 0.05). The immediate resuscitation O(2)D response correlated significantly (p < 0.001) with base deficit and lactate, but blood pressure was not a significant discriminator. Seven-day biopsies showed return of bowel mucosa but a pattern of cellular injury in heart, liver, and kidney that improved from 8.4% < 15% < 30 < 120% immediate resuscitation. CONCLUSION: The data suggest that, compared with 120% postshock immediate resuscitation, 8.4% and 15% immediate resuscitation give poorer results, with 30% immediate resuscitation showing mild, transient, but acceptable changes in organ function allowing for a 2-hour delay until full resuscitation, with complete 7-day recovery. Base deficit and lactate, but not blood pressure, are significant indices of O(2)D.