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Biomedical subjects

Gerald McGwin

Publications and source records attributed to Gerald McGwin.

At least 127 records · Page 7Linked to original sources

Death during theft from electric utilities.

Utilities that supply power are subject to theft of service and theft of hardware used to provide service. Individuals who try to steal from a power utility risk electrocution. We conducted a retrospective study of all individuals examined by the Jefferson County Coroner Medical Examiner Office from January 1981 through December 2001 and found that 8 individuals died trying to steal from a power utility. All decedents were men, with an average age of 33 years. Seven decedents were stealing copper, and 1 was stealing electricity. Only 1 decedent survived long enough to be admitted to a hospital. Five decedents were intoxicated, 3 with ethanol, 1 with cocaine, and 1 with both cocaine and ethanol. Seven decedents sustained electrical burns in keeping with the high voltage to which they were subjected. The unburned decedent died of laceration of the aorta at its origin from the heart, an injury sustained when the decedent fell from the power pole. All 8 decedents attempted their theft during daylight. Items found in the decedent's pockets, the presence of a ladder nearby, or the presence of electrical tools around the body may help to establish the attempted act of theft.

Adolescent↗

Motor vehicle crash-related mortality is associated with prehospital and hospital-based resource availability.

BACKGROUND: To date, attempts to assess the relationship between motor vehicle collision (MVC)-related mortality and medical resources availability have largely been unsuccessful. METHODS: Information regarding sociodemographic characteristics, prehospital resources, and hospital-based resources for each county (n = 67) in the state of Alabama was obtained. MVC-related mortality rates (deaths per 1,000 collisions) by county were calculated and compared according to prehospital and hospital-based resource availability within each county after correcting for sociodemographic factors. RESULTS: Counties with 24-hour availability of a general surgeon, orthopedic surgeon, neurosurgeon, computed tomographic scanner, and operating room were shown to have decreased MVC-related mortality (relative risk [RR], 0.88). The same was true for those counties with hospitals classified as Level I-II (RR, 0.71) and Level III-IV (RR, 0.83) trauma centers compared with counties with no trauma centers. CONCLUSION: Appropriate, readily available hospital-based resources are associated with lower MVC-related mortality rates. This information may be useful in trauma system planning and development.

Accidents, Traffic↗

Relationship between age and lower extremity fractures in frontal motor vehicle collisions.

BACKGROUND: Older adults (aged > or = 65 years) represent the single fastest growing segment of the United States population and will comprise one in five Americans during the third decade of this century. As this population segment rapidly expands, lower extremity fractures (LE Fx) and their associated disability will become a greater public health concern. The purpose of this study was to quantify the risk for LE Fx from motor vehicle collisions (MVCs) according to age. METHODS: The 1995 to 2000 National Automotive Sampling System data files were used. Study entry was limited to front-seat occupants involved in frontal MVCs. Risk ratios for LE Fx and age were adjusted for gender, driver versus passenger, seat belt use, airbag deployment, delta-V, intrusion, and vehicle type. RESULTS: Beginning in the fourth decade, there was a trend of higher relative risk for LE Fx with age that reached statistical significance in the seventh decade of life. CONCLUSION: This study documented an increased risk of LE Fx in older MVC occupants. Efforts to prevent these disabling injuries and to better protect occupants' lower extremities in MVCs should include improved vehicle design and reevaluation of the existing federal motor vehicle safety standards.

Accidents, Traffic↗

The association between gender and mortality among trauma patients as modified by age.

BACKGROUND: Several studies have reported a null association between gender and mortality after traumatic injury, whereas others found an age-specific association between male gender and increased mortality. Relatively small sample sizes may have contributed to the heterogeneity among existing studies; therefore, a large-sample-size study was undertaken. METHODS: The National Trauma Data Bank was queried, yielding data for over 150,000 patients involved in blunt or penetrating trauma. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for the association between gender and mortality, both overall and according to mechanism of injury and age categories. RESULTS: Among those who sustained blunt trauma, male patients had a significant increase in the risk of death compared with female patients (OR, 1.49; 95% CI, 1.39-1.59) that was most apparent for those > or = 50 years of age (OR, 1.97; 95% CI, 1.84-2.11). For penetrating trauma patients, essentially no significant association, either overall (OR, 1.03; 95% CI, 0.91-1.17) or by age category, was apparent. CONCLUSION: This study found an association between gender and mortality among blunt trauma patients, particularly those aged > or = 50 years. Animal studies demonstrate that the sex hormones influence the inflammatory response to injury. These results may highlight the importance of sex hormones in traumatic injury outcomes.

Adult↗

Occupant- and collision-related risk factors for blunt thoracic aorta injury.

BACKGROUND: Blunt thoracic aortic injury (BAI) is a rare and highly lethal injury. We sought to identify occupant and collision characteristics associated with motor vehicle collision (MVC)-related BAI. METHODS: The 1995 to 2000 National Automotive Sampling System data files were used. The National Automotive Sampling System is a national probability sample of passenger vehicles involved in police-reported tow-away MVCs. The risk of BAI was calculated according to specific occupant (e.g., age, seat belt use) and collision (e.g., delta-V [estimated change in velocity], vehicular intrusion) characteristics. The association between BAI and these characteristics was calculated using risk ratios (RRs) and associated 95% confidence intervals (CIs). RESULTS: Specific occupant and collision characteristics demonstrated independent association with BAI. Occupant characteristics included age >or= 60 (RR, 3.6; 95% CI, 2.5-5.2), seat belt use (RR, 0.3; 95% CI, 0.2-0.5), and being a front-seat occupant (RR, 3.1; 95% CI, 1.5-6.3). Frontal and near-side MVCs were associated with an increased risk (RR, 3.1; 95% CI, 1.9-5.1; and RR, 4.3; 95% CI, 2.6-7.2, respectively) relative to other collision types. Collisions with a delta-V >or= 40 km/h (RR, 3.8; 95% CI, 2.6-5.6) or that produce extensive vehicle crush (>or= 40 cm) (RR, 4.1; 95% CI, 2.7-6.3) or intrusion (>or= 15 cm) (RR, 5.0; 95% CI, 3.5-7.3) also increase the risk of BAI. CONCLUSION: The risk factors for BAI identified in this study support generally accepted etiologic mechanisms for this injury.

Accidents, Traffic↗

The association between occupant restraint systems and risk of injury in frontal motor vehicle collisions.

BACKGROUND: An evaluation of seat belt use and airbag deployment, either alone or in combination, on risk of injury to specific body regions has yet to be completed. METHODS: A retrospective cohort study of front seat occupants involved in police-reported, tow-away, frontal motor vehicle collisions using data from the 1995 through 2000 National Automotive Sampling System was conducted. Only vehicles with a change in velocity (delta-V) of >/= 15 km/h were included. Risk of injury (Abbreviated Injury Scale score >/= 2) to specific body regions was compared according to seat belt use and airbag deployment. RESULTS: Compared with completely unrestrained occupants, those using a seat belt alone or in combination with an airbag had a reduced overall risk of injury (relative risk, 0.42 and 0.71, respectively); no association was observed for those restrained with an airbag only (relative risk, 0.98). This pattern of results was similar for specific body regions with the exception of the lower extremity, wherein a significantly increased risk was observed for airbag deployment alone. CONCLUSION: Airbag deployment does not appear to significantly reduce the risk of injury either alone or in combination with seat belts. Airbag deployment without associated seat belt use may increase the risk of lower extremity injury.

Accidents, Traffic↗

Association between side air bags and risk of injury in motor vehicle collisions with near-side impact.

BACKGROUND: Side air bags (SABs) have been introduced in an attempt to reduce the risk of injury in near-side-impact motor vehicle collisions (MVCs). The impact of SABs on MVC-related mortality and morbidity has yet to be evaluated with a large population-based study. The objective of this study was to assess the effectiveness of SABs in reducing the risk of injury or death in near-side-impact MVCs. METHODS: A retrospective study investigated outboard front seat occupants involved in police-reported, near-side-impact MVCs using data from the General Estimates System (1997-2000). The risk of MVC-related nonfatal and fatal injury for occupants of vehicles with and without SABs was compared. RESULTS: Front seat occupants of vehicles with SABs had a risk of injury similar to that of occupants of vehicles without SABs (risk ratio [RR], 0.96; 95% CI confidence interval [CI], 0.79-1.15). Adjustment for the potentially confounding effects of age, gender, seat belt use, seating position, damage severity and location, and vehicle body type did not meaningfully affect the association (RR, 0.90; 95% CICI, 0.76-1.08). CONCLUSIONS: There is no association between the availability of SABs and overall injury risk in near-side-impact MVCs. Future research is necessary to determine the effectiveness of SABs in preventing the injuries for which they were specifically designed.

Accidents, Traffic↗

Racial differences in the association between optic disc topography and early glaucoma.

PURPOSE: To determine the structural characteristics of the optic disc that are associated with early glaucoma in African Americans and whites and whether these characteristics differ between the races. METHODS: Parameters of optic disc topography from 260 African American eyes and 193 white eyes were included in the analysis. One hundred forty-four eyes of African Americans and 109 eyes of normal white subjects were used as a control group. Logistic regression was used to calculate the association between early glaucoma, defined by the visual field, and cup, rim, and disc margin confocal scanning laser ophthalmoscopic (CSLO) parameters, using odds ratios at binary cut points. The cup, rim, and disc margin parameters identified as being independently associated with glaucoma in these reduced models were then included in a single multivariate model. Optic disc area was included in the analysis at each level of the model. This approach was used for the total study group and then separately for the African American and white groups. RESULTS: When accounting for difference in optic disc area, rim area had the highest independent association with early glaucoma in both groups, but this association was lower in African Americans (odds ratio [95% confidence interval]: 1.63 [1.12-2.36]) than in whites (odds ratio: 4.74 [2.18-10.28]). Additional independently associated parameters included cup shape, maximum elevation along the contour line, and the temporal-to-inferior contour line modulation ratio in whites and cup shape and the temporal-to-superior contour line modulation ratio in African Americans. CONCLUSIONS: Structural characteristics of the optic disc that are best associated with early glaucoma included cup shape and rim area in both groups, but with a less pronounced association in African Americans. In addition, several other race-specific parameters that were independently associated with early glaucoma differed significantly between African Americans and whites. These race-specific differences were independent from the effect of optic disc area.

Alabama↗

Intramedullary nailing of humeral shaft fractures with a locking flexible nail.

BACKGROUND: Studies on intramedullary nailing of humeral shaft fractures in the orthopaedic literature have shown mixed results. The purpose of this investigation was to document the clinical outcome and complications associated with the use of a new flexible, locking intramedullary nail that can be implanted in the humerus in either a retrograde or an antegrade manner without violating the rotator cuff mechanism or damaging the articular surface of the humeral head. METHODS: Fifty consecutive patients with fifty-one humeral shaft fractures were entered into our prospective clinical outcome study. The fracture was classified on the basis of the anatomic location and pattern. Implant positioning and fracture alignment were assessed postoperatively. Complications were recorded, and the time to union was measured. Shoulder function was evaluated with use of a combination of the Constant shoulder score, Short Form-36 (SF-36) clinical outcome data, range-of-motion measurements, and a subjective pain-rating scale. RESULTS: Forty-one patients with forty-two fractures had an adequate duration of clinical follow-up (a mean of twenty-two months) for analysis. Thirty-nine fractures healed, with a mean time to clinical union of twelve weeks (range, four to fifty weeks). Thirty-eight of the forty-two shoulders had minimal or no pain. Thirty-six shoulders had a full range of motion. The mean Constant shoulder score was 90 points. Four patients had five complications, which included two nonunions, two hardware failures, and one wound infection. All four patients had been managed with a 7.5-mm nail. A multivariate analysis demonstrated that an age of more than fifty years was associated with a lower Constant score and that the occurrence of a complication was associated with a lower physical component score on the SF-36. CONCLUSIONS: The flexible humeral nail allows both retrograde and antegrade implantation and static locking. Nail insertion can be accomplished without violating the rotator cuff or damaging the articular surface of the humeral head. Although the nail functioned well in most of our patients, the use of a small-diameter (7.5-mm) nail was associated with a higher complication rate. This implant should be used with caution in any patient with a medullary canal diameter of <or=8 mm.

Adolescent↗

Early versus delayed fixation of pelvic ring fractures.

This retrospective study reports outcomes, after early and delayed surgical stabilization of fractures of the pelvic ring, in terms of pulmonary complications, length of hospital stay, and cost of hospitalization. The hospital course of 151 patients admitted to an academic teaching hospital who sustained acute fractures of the pelvic ring between June 1996 and December 2000 was reviewed. Patient demographics, Injury Severity Score (ISS), timing of operative fixation, and the incidence of pulmonary complications were analyzed. Radiographs were reviewed and fractures classified according to the modified Tile system. Tile fracture types B and C patients who underwent fixation within 1 week of injury (n = 71) were compared to those in whom surgery was delayed (n = 28). Adjusting for the ISS, early-repair patients had a lower risk of pulmonary complications (RR = 0.49, 95% CI = 0.25-0.96), a reduced length of hospital stay (12.2 vs. 20.5 days; P = 0.0005), and overall reduced cost of care (57,084 dollars vs. 158,625 dollars; P = 0.0317). Pelvic ring fixation within the first week of injury results in significantly reduced incidence of pulmonary complication, hospital stay, and cost of care regardless of injury severity. The coordinated team approach to insure prompt resuscitation, stabilization, and operative fixation results in more optimal patient outcomes.

Adult↗

Impact of cataract surgery on motor vehicle crash involvement by older adults.

CONTEXT: Motor vehicle crash risk in older drivers is elevated in those with cataract, a condition that impairs vision and is present in half of adults aged 65 years or older. OBJECTIVE: To determine the impact of cataract surgery on the crash risk for older adults in the years following surgery, compared with that of older adults who have cataract but who elect to not have surgery. DESIGN, SETTING, AND PATIENTS: Prospective cohort study of 277 patients with cataract, aged 55 to 84 years at enrollment, who were recruited from 12 eye clinics in Alabama from October 1994 through March 1996, with 4 to 6 years of follow-up (to March 1999). MAIN OUTCOME MEASURE: Police-reported motor vehicle crash occurrence involving patients who elected to have surgery compared with those who did not. RESULTS: Comparing the cataract surgery group (n = 174) with the no surgery group (n = 103), the rate ratio for crash involvement was 0.47 (95% confidence interval, 0.23-0.94), adjusting for race and baseline visual acuity and contrast sensitivity. The absolute rate reduction associated with cataract surgery was 4.74 crashes per million miles of travel. CONCLUSIONS: In our sample, patients with cataract who underwent cataract surgery and intraocular lens implantation had half the rate of crash involvement during the follow-up period compared with cataract patients who did not undergo surgery. Cataract surgery thus may have a previously undocumented benefit for older driver safety, reducing subsequent crash rate.

Accidents, Traffic↗

Systemic lupus erythematosus in three ethnic groups. X. Measuring cognitive impairment with the cognitive symptoms inventory.

OBJECTIVE: To determine the factor structure of the Cognitive Symptoms Inventory (CSI) in patients with systemic lupus erythematosus (SLE) participating in a multiethnic longitudinal study of outcome, the Lupus in Minority populations, Nature versus nurture (LUMINA) study. METHODS: LUMINA patients of Hispanic (n = 48), African American (n = 64), and Caucasian (n = 44) ethnicity who had a study visit (enrollment or followup) between January 1 and September 30, 2000 were included. Patients completed the CSI, a 21-item self-report measure of cognitive function. Sociodemographic, clinical, immunologic, psychosocial, and behavioral variables were ascertained per protocol and as previously described. Data were analyzed with SPSS. The factor structure of the CSI was determined using the principal axis method with oblique rotation as decided by Gorsuch. All factors having an Eigenvalue greater than 1 were considered. A 4-factor solution was derived that accounted for 42.6% of the common variance. The correlations between patient factor scale scores and variables from the demographic, clinical, psychosocial, and behavioral domains were then examined. RESULTS: The four factors and their respective variance are, Attention/Concentration (28.8%), Pattern Recognition/Activity Management (5.7%), Intermediate Memory (4.7%), and Initiation of Executive Functions (3.4%); each factor correlated with the total CSI score. Overall, patients' factor scale scores were positively and significantly correlated with other measures of cognitive dysfunction such as the Systemic Lupus Activity Measure (neuromotor domain) or the Systemic Lupus International Collaborating Clinics Damage Index (neurocognitive impairment), as well as with measures of fatigue, maladaptive coping skills, poor mental functioning, poor social support, and helplessness. They were, however, not correlated with sociodemographic or clinical variables. CONCLUSIONS: In addition to demonstrating that the CSI can be used to measure cognitive impairment in patients with SLE in the research setting, we have determined a 4-factor solution for the CSI that appears to have adequate metric properties. At present, the CSI may best be used as a screen for difficulties in daily activities involving intermediate memory, concentration, attention, and executive function. Nevertheless, further work with the CSI items and factor scales is necessary to establish internal and test-retest reliability of the factor scales; and provide additional evidence of the convergent and predictive validity of these scales in larger samples of patients from each ethnic subgroup.

Adult↗

Systemic lupus erythematosus in three ethnic groups. XI. Sources of discrepancy in perception of disease activity: a comparison of physician and patient visual analog scale scores.

OBJECTIVE: To compare patient's and physician's assessment of disease activity in a multiethnic (Hispanic, African American, and Caucasian) cohort of systemic lupus erythematosus (SLE) patients. METHODS: Three hundred patients with SLE from the LUMINA (Lupus in Minority populations: Nature versus nurture) cohort were included. Disease activity was assessed with the Systemic Lupus Activity Measure (SLAM); patients and physicians assessed disease activity using a 10-cm anchored visual analog scale (VAS). The difference between VAS scores was termed discrepancy (>1 cm was considered a priori clinically relevant). Selected sociodemographic, clinical, behavioral, and psychological variables were examined in relation to discrepancy in univariable and multivariable models adjusting for the physician global VAS score in order to eliminate ceiling and floor effects. RESULTS: A discrepancy was exhibited by 58% of the patients. Abnormal laboratory findings were negatively associated with discrepancy, and poor self-perceived functioning and joint involvement were positively associated with discrepancy. Ethnicity did not account for discrepant perception of disease activity. CONCLUSION: Patients and physicians rate disease activity in SLE differently. Physicians appear to place more emphasis on laboratory features while patients place more emphasis on function.

Adult↗

Heterotopic ossification associated with knee dislocation.

PURPOSE: The purpose of this study was to determine the prevalence of heterotopic ossification following knee dislocation. TYPE OF STUDY: Prospective clinical evaluation and a retrospective chart review. METHODS: This study evaluated 57 knees in 55 patients who sustained high-energy blunt trauma with resultant knee dislocations. Radiographs were reviewed by 2 of the authors (J.P.S., T.C.W.), and the incidence of heterotopic ossification (HO) was documented. Additionally, patients were classified regarding the degree of HO on a scale from 0 to 4. One is punctate calcification, 2 is HO involving less than 50% of the joint space; 3 is HO involving more than 50%; and 4 is ankylosis of the joint. RESULTS: Thirteen patients with 15 knee dislocations developed HO. The incidence of HO was 26%. Seven knees demonstrated severe HO (grade 3 or 4) which represented an incidence of 12% of all knee dislocations. Injury severity score for both groups was 18, documenting that the patients in this study represent multiple trauma patients. There was no significant difference in the incidence of HO based on mechanism of injury with the current number enrolled in the study. However, 60% (3 of 5) of patients involved in a motor vehicle versus pedestrian accident developed HO. There was a significant increase in the incidence of arthrofibrosis in patients with severe HO (P <.05). Patients with significant HO had a mean flexion of 97 degrees, compared with flexion of 117 degrees in patients with no or mild HO. This difference was borderline significant (P =.058). There was no difference between the groups in mean extension. There was a significant increase in knee HO in patients with HO at another anatomic site (P =.01). CONCLUSIONS: HO is a common problem following knee dislocation. Of the 7 knees with severe HO, 5 developed HO medially, 4 developed HO posteriorly, 3 developed HO laterally, and only 1 had involvement anteriorly. A similar distribution was present in the patients with mild HO, with posterior and medial ossification being the most common. Five of the 7 severe HO cases involved at least 3 of the 4 sides (anterior, posterior, medial, or lateral) of the knee. Patients were evaluated for the presence of head injury and any relationship to the development of HO around the knee. There was no increased incidence of HO around the knee in our 10 patients with severe head injuries when compared with those with no head injury. There was also no increased incidence of HO in knee dislocations associated with periarticular fractures.

Adolescent↗

Restraint use and injury patterns among children involved in motor vehicle collisions.

BACKGROUND: Motor vehicle collisions are the leading cause of death among children older than 1 year. Use of appropriate restraint systems is associated with reductions in morbidity and mortality in this age group. No studies have evaluated the association between specific injury patterns and restraint use among children. The purpose of this study was to evaluate differences in risks of injuries in different body regions according to restraint use among children 0 to 11 years of age. METHODS: The 1995 to 1999 National Automotive Sampling System data files were used. The National Automotive Sampling System is a national probability sample of passenger vehicles involved in police-reported tow-away collisions. Information on occupant (seating position, restraint use), collision (change in velocity, vehicle intrusion), and outcome characteristics was evaluated. Risks of injuries in different body regions (Abbreviated Injury Scale, 1990 Revision score > or = 2) were calculated and compared according to restraint use. RESULTS: Between 1995 and 1999, there were approximately 1.5 million children 0 to 11 years of age involved in police-reported tow-away MVCs who met the inclusion criteria for this study. Compared with unrestrained children, properly restrained children had significantly lower overall injury risk (risk ratio [RR], 0.37); significant risk reductions were also observed for injuries to the head (RR, 0.18), thorax (RR, 0.35), and lower extremities (RR, 0.26), and mortality (RR, 0.26). Significant risk reductions were not noted when comparing improperly restrained children with unrestrained children. CONCLUSION: Proper restraint use among children is associated with lower risk of injury. Educational initiatives should focus not only on encouraging restraint use but also on ensuring that parents know the appropriate age-dependent restraint method and how to use it properly.

Accidents, Traffic↗

Incidence and characteristics of motor vehicle collision-related blunt thoracic aortic injury according to age.

BACKGROUND: Motor vehicle collision-related blunt thoracic aorta injury (BAI) is rare and highly lethal. Vascular disease as related to advancing age potentially subjects older adults to increased risk of BAI; the mechanisms associated with such injuries may be different as compared with younger adults. The goal of the present study is to test this hypothesis using population-based data. METHODS: The 1995 to 1999 National Automotive Sampling System data files were used. The National Automotive Sampling System is a national probability sample of passenger vehicles involved in police-reported tow-away crashes. BAI was defined according to the Abbreviated Injury Scale codes. Among those with BAI, information on occupant (age, seating position, restraint use), collision (collision type, delta-V, vehicle intrusion), and outcome characteristics were obtained and compared according to age. RESULTS: The overall incidence of BAI was 6.8 per 10,000 occupants and there was a steady increase in the BAI rate for advancing decades of life. The proportion of occupants with BAI who die at the scene of the collision is relatively consistent across all age groups ( approximately 85%). Among those who survive to receive medical care, ultimate survival is lowest among those aged 60 and older. Near-side collisions were responsible for more BAI among older adults than other age groups (50% vs. 20.6%, p < or = 0.05). Older adults sustained BAI in collisions with lower delta-V values compared with younger persons (p < or = 0.05). CONCLUSION: Older adults have the highest rate of motor vehicle collision-related BAI, and their injuries tend to occur in less severe collisions. A high level of suspicion for BAI among older adults should not be reserved for high-energy collisions only.

Accidents, Traffic↗

Injury rates among restrained drivers in motor vehicle collisions: the role of body habitus.

BACKGROUND: Previous studies have examined the independent effects of occupant height, obesity, and body mass index in motor vehicle collisions and identified related injury patterns. The hypothesis of this study was that as the driver's body habitus diverges from the 50% percentile male Hybrid III Crash Dummy (H3CD), the frequency of injury changes. METHODS: The 1995 to 1999 National Automotive Sampling System Crashworthiness Data System was used. Study entry was limited to restrained drivers who were then subdivided into height and weight categories. Incidence rates were calculated for injuries to selected body regions as defined by the Abbreviated Injury Scale for overall, frontal, and driver's side collisions. RESULTS: When grouped according to height and weight as descriptors of body habitus, injury rates for restrained drivers were increased as well as decreased in several subgroups. This association was seen in overall, frontal, and driver's side collisions. CONCLUSION: The H3CD plays a major role in vehicular cabin interior design and crash testing. For drivers with a body habitus different from that of the H3CD, the vehicle cabin/body fit changes and the safety features may perform differently, which could account for these observations.

Accidents, Traffic↗