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Biomedical subjects

R V Maier

Publications and source records attributed to R V Maier.

At least 19 recordsLinked to original sources
PubMed1997

The effect of payer status on utilization of hospital resources in trauma care.

OBJECTIVE: To determine the effect of payer status on outcome and resource utilization in motor vehicle-related trauma patients. DESIGN: Retrospective cohort analysis that assessed the effect of payer status on outcome and resource utilization. SETTING: The single level I trauma center in a regionalized statewide system. PATIENTS: Consecutive patients (N = 3141) who were hospitalized after a motor vehicle crash during a 3-year period. MAIN OUTCOME MEASURES: The mortality rate, disposition, total hospital length of stay (LOS), total intensive care unit LOS, and total hospital charges were examined for 2 categories of payers: "commercial insurance" (commercial, labor and industry, and contract pay) and "noncommercial insurance" (Medicaid and self-pay). RESULTS: After controlling for age, sex, race, and the Injury Severity Score, the payer status had no overall effect on the mortality rate, disposition, total hospital charges, total hospital LOS, or total intensive care unit LOS. However, there was a significantly (11.4%; P < .05) longer LOS for those patients with noncommercial insurance who required transfer to another facility for rehabilitation or long-term care. CONCLUSIONS: The utilization of hospital trauma care resources in a level I facility in a regionalized system was not associated with insurance status. Patients with noncommercial insurance who required transfer to elective long-term care facilities had a longer LOS due to delays in obtaining subsequent access. Health care policy should provide appropriate reimbursement for all aspects of regionalized trauma care systems to ensure maintenance of an egalitarian approach to care.

Accidents, Traffic↗
PubMed1997

Fat embolism syndrome. A 10-year review.

BACKGROUND: The effect of recent advances in critical care and the emphasis on early fracture fixation in patients with fat embolism syndrome (FES) are unknown. OBJECTIVE: To better define FES in current practice by conducting a 10-year review of the experiences at our level I trauma center. DESIGN: The medical records of all patients in whom FES was diagnosed from July 1, 1985, to July 1, 1995, were reviewed for demographics, injury severity and pattern, diagnostic criteria, and management. SETTING: A level I trauma center. RESULTS: Twenty-seven patients with clinically apparent FES were identified. This resulted in an incidence of 0.9% of all patients with long-bone fractures. The mean injury severity score was 9.5 (range, 4-22). The diagnosis of FES was made by clinical criteria, including hypoxia, 26 patients (96%); mental status changes, 16 patients (59%); petechiae, 9 patients (33%); temperature higher than 39 degrees C, 19 patients (70%); tachycardia (heart rate > 120 beats per minute), 25 patients (93%); thrombocytopenia (platelet count < 150 x 10(9)/L), 10 patients (37%); and unexplained anemia, 18 patients (67%). Thirteen patients (48%) had multiple long-bone fractures, and 14 patients (52%) had a single long-bone fracture. Seven patients (26%) had open fractures, 15 (56%) had closed fractures, and the remaining 5 (18%) had both. Of the total fracture population, the distribution was 81% closed, 15% open, and 4% both. Management included ventilatory support for 12 (44%) of the patients; early operative fixation was emphasized, and 74% of the fractures were stabilized within 24 hours of injury. This was comparable with 76% of the total fracture population. There were 2 deaths, for a mortality of 7%. CONCLUSIONS: (1) Fat embolism syndrome remains a diagnosis of exclusion and is based on clinical criteria. (2) Clinically apparent FES is unusual but may be masked by associated injuries in more severely injured patients. (3) No association could be identified between FES and a specific fracture pattern or location. (4) Early intramedullary fixation does not increase the incidence or severity of FES. (5) While FES seems to have a direct effect on survival, the management of FES remains primarily supportive.

Adolescent↗
PubMed1997

The complications of trauma and their associated costs in a level I trauma center.

OBJECTIVES: To estimate the expected costs for acute trauma care, to quantify the costs associated with the development of complications in injury victims, and to determine the deficit incurred by patients in whom complications develop. DESIGN: A retrospective, cohort design. SETTING: A referral trauma center. PATIENTS: A total of 12,088 patients admitted to a single regional trauma center during a period of 5 years. INTERVENTIONS: This is an observational study, and no interventions specific to this study are included in the design. MAIN OUTCOME MEASURES: (1) The expected costs for injury victims based on readily available clinical data. (2) The costs associated with the most important complications of trauma. (3) The effect of complications on inadequate reimbursement for trauma care. RESULTS: The expected costs were estimated using a linear model incorporating demographic variables and measures of injury severity. The expected costs averaged $14,567, and the observed costs averaged $15,032. Six complications were important predictors of cost. These included adult respiratory distress syndrome, acute kidney failure, sepsis, pneumonia, decubitus ulceration, and wound infections. For 1201 individuals with these complications, the predicted costs averaged $23,266 and the observed costs averaged $47,457. The mean excess costs for a single complication ranged from $6669 to $18,052. Multiple complications led to greater increases in excess cost, averaging $110,007 for the 62 patients with 3 or more complications. Costs exceeded reimbursement to a much greater degree in those in whom any of the 6 complications developed. CONCLUSION: Expected hospital costs can be estimated using admission clinical data. Each of 6 complications was associated with enormous increases in costs, indicating their importance as a cause of avoidable expenditures in injury victims and identifying situations in which reimbursement may not be adequate.

Cohort Studies↗
PubMed1997

Diagnosis of injuries after stab wounds to the back and flank.

BACKGROUND: Historically, patients with deep posterior wounds underwent a formal celiotomy to rule out injury. Currently, we use a policy of selective management. The purpose of this review is to evaluate our experience with selective management to identify potential areas of further improvement. METHODS AND RESULTS: This study includes 203 patients over a 10-year period. By changing from a policy of mandatory exploration to selective management the total celiotomy rate decreased from 100 to 24% and the therapeutic celiotomy rate increased from 15 to 80%. CONCLUSIONS: In stable patients, a diagnostic peritoneal lavage should be performed as the initial diagnostic study. When diagnostic peritoneal lavage is negative, triple contrast computed tomography should be performed to evaluate the remaining retroperitoneal structures. Any suggestion of pericolonic extravasation of contrast or air, edema, or hemorrhage must be interpreted as a positive study and prompt consideration for operative exploration.

Abdominal Injuries↗
PubMed1997

Pressure sores in the acute trauma patient: incidence and causes.

OBJECTIVES: The purpose of this review was to determine the incidence of pressure sores in acute trauma patients and to identify the causes. DESIGN AND MATERIALS AND METHODS: This study is a retrospective chart review of all acute trauma patients admitted to Harborview Medical Center between January of 1991 and December of 1993 who were discharged with an ICD-9 diagnosis of acute pressure sore. RESULTS: A total of 7,492 trauma patients were admitted. Thirty-two patients developed 44 pressure sores for an incidence of 0.4%. All of the patients were severely injured (mean Injury Severity Score, 21). Eighteen (41%) of the pressure sores developed as a result of unrelieved positional pressure. Thirteen (30%) of the pressure sores were equipment induced. CONCLUSION: Our incidence of pressure sores in acute trauma victims is very low and occurs in those most seriously injured. The majority of the wounds are due to unrelieved pressure from body positioning or equipment failure.

Adult↗
PubMed1997

Low utilization of formal medical services by injured persons in a developing nation: health service data underestimate the importance of trauma.

BACKGROUND: Assessment of the societal importance of trauma relies, in large part, on hospital and other health service data. Such data are of limited value in developing nations if a significant proportion of injured persons do not receive formal medical care. METHODS: We undertook an epidemiologic study of trauma in Ghana. Via household visits, we surveyed 21,105 persons living in 432 urban and rural sites. RESULTS: During the preceding year, there had been 13 fatal injuries (62 per 100,000) and 1,597 nonfatal injuries resulting in > or = 1 days of lost activity (7 per 100). Of the fatally injured, only 31% received formal medical care (hospital or clinic). Of the nonfatal injuries, 58% received formal care, but with major differences between urban and rural sites. Only 51% of rural injured received formal medical care, compared with 68% of urban injured (p < 0.001). Even among those with more severe injuries (disability time > or = 1 month), 26% of rural injured never had formal care. Overall hospital use was especially low, with only 27% of all injured persons using hospital services. Among those with more severe injuries, 60% of urban, but only 38% of rural injured received hospital care (p < 0.001). CONCLUSIONS: These data indicate low utilization of formal medical services by injured persons in this developing nation. Even many of those with severe injuries do not receive medical care, especially in rural areas. Assumptions that rely on health service data, especially hospital data, underestimate the importance of trauma. Appropriate commitment of health care resources might thus be affected. Population based data are needed to fully assess the extent and societal impact of injuries in developing nations.

Data Interpretation, Statistical↗
PubMed1997

Urban-rural differences in prehospital care of major trauma.

OBJECTIVES: To compare differences in response times, scene times, and transport times by advanced life-support-trained paramedics to trauma incidents in urban and rural locations. METHODS: This report was a prospective cohort study of professional emergency medical services conducted in a five-county area in the state of Washington. Ninety-eight percent of trauma transports are provided by professional paramedics trained in advanced life support. Subjects were included in this study if they qualified as a major trauma victim and were transported or found dead at the scene by one of the region's advanced life support transport agencies between August 1, 1991, and January 31, 1992. The severity of injury was rated using the Prehospital Index. Incident locations were defined as "rural" if they occurred in a US Census division (a geographic area) in which more than 50% of the residents resided in a rural location. RESULTS: During the 6-month data collection period, advanced life support agencies responded to a total of 459 major trauma victims in the region. A geographic locations was determined for 452 of these subjects. Of these, 42% of subjects were injured in urban areas and the remainder in rural areas. The severity of injuries, as determined both by the triage classification (p = 0.17) and the distribution of Prehospital Index scores (p = 0.92), was similar for urban and rural major trauma patients. Twenty-six (5.7%) subjects died at the scene. About one quarter of both groups had a severe injury, as indicated by Prehospital Index score of more than 3. The mean response time for urban locations was 7.0 minutes (median = 6 minutes) compared with 13.6 minutes (median = 12 minutes) for rural locations (p < 0.0001). The mean scene time in rural areas was slightly longer than in urban areas (21.7 vs. 18.7 minutes, p = 0.015). Mean transport times from the scene to the hospital were also significantly longer for rural incidents (17.2 minutes vs. 8.2 minutes, p < 0.0001). Rural victims were over seven times more likely to die before arrival (relative risk = 7.4, 95% confidence interval 2.4-22.8) if the emergency medical services' response time was more than 30 minutes. CONCLUSIONS: Response and transport times among professional, advanced life-support-trained paramedics responding to major trauma incidents are longer in rural areas, compared with urban areas.

Algorithms↗
PubMed1997

Effects of an immune-enhancing diet in critically injured patients.

OBJECTIVE: To determine the effects of an immune-enhancing experimental diet (XD = supplemental arginine, trace elements, and increased omega-3 fatty acids) versus standard diet (SD), on immune cell function and clinical outcome of critically injured patients. DESIGN: Prospective randomized clinical trial of patients admitted to the surgical intensive care unit after trauma (Injury Severity Score > 13). MATERIALS AND METHODS: Patients received early enteral nutrition with either XD or SD for a minimum of 5 days. MEASUREMENTS: Mortality, intensive care unit, ventilator, and hospital days, as well as incidence of adult respiratory distress syndrome (ARDS) and infectious complications were recorded. Nutritional parameters were also studied. Peripheral blood leukocytes were isolated from normal volunteers and from patients on days 1, 6, and 10 of feeding. MAIN RESULTS: Demographics and injury severity were similar in both groups. Both SD (n = 21) and XD (n = 22) groups revealed depressed monocyte function (tumor necrosis factor, prostaglandin E2, and procoagulant activity) on day 1 compared with a reference group (p < 0.05). However, monocytes from XD patients began to "normalize" their response (tumor necrosis factor, prostaglandin E2, and procoagulant activity) by day 6. Although ARDS occurred more frequently in the XD group (45 vs. 19%), the majority of ARDS in both groups occurred very early, with only three patients in the XD (13.6%) and one patient in the SD (4.7%) groups developing ARDS after study entry. XD patients remained on the ventilator longer (16.4 vs. 9.7 days) and in the hospital longer (32.9 vs. 22 days) compared with the SD group, but overall mortality was nearly identical (4.5 vs. 5%). CONCLUSION: The exact role and timing for diets with immune-enhancing effects has yet to be defined.

Adjuvants, Immunologic↗
PubMed1997

New regimens in the management of posttraumatic respiratory failure.

Many individuals are now surviving their injuries to face the consequences of an activated immunoinflammatory system and the complications of supportive therapy. The pulmonary system bears the force of this insult. An understanding of the epidemiology of acute respiratory failure, as well as a greater knowledge of the cellular and subcellular mechanisms by which pulmonary dysfunction occurs, has led to novel approaches to the management of acute respiratory failure. It also appears that lung injury is caused, or at least exacerbated, by iatrogenic insults, such as positive-pressure ventilation. The purpose of this review is to discuss the etiology and pathophysiology of acute respiratory failure following severe injury and the novel therapeutic approaches. A combination of immunomodulating and mechanical ventilation strategies will likely provide the most successful approach to reducing the morbidity and mortality associated with acute respiratory failure following injury.

Humans↗
PubMed1996

Calcium and calmodulin regulate lipopolysaccharide-induced alveolar macrophage production of tumor necrosis factor and procoagulant activity.

BACKGROUND: Alterations in macrophage (M phi) function are responsible, in part, for adult respiratory distress syndrome and multiple organ failure developing in patients with sepsis. Elucidation and control of these M phi mechanisms during sepsis are crucial to our understanding of this disease and, ultimately, to improving survival of these patients. OBJECTIVE: To investigate the involvement of calcium flux in endotoxin-induced alveolar M phi production of tumor necrosis factor (TNF) and procoagulant (PC) activity. DESIGN: Rabbit alveolar M phi obtained by bronchoalveolar lavage were exposed to endotoxin in the form of lipopolysaccharide (LPS) extracted from Escherichia coli 0111:B4 in the presence of different specific calcium agonists and antagonists. The TNF expression was measured in the supernatant by L929 bioassays. The PC activity was determined in cell lysates by a one-step coagulation assay. RESULTS: Macrophages activated by LPS produce enormous levels of TNF and PC. Either W7 (20 mumol/L), a calmodulin antagonist, or TMB-8 (50 mumol/L), which prevents calcium release from the endoplasmic reticulum, inhibited production of both TNF and PC activity. Verapamil (50 mumol/L) alone or combined with TMB-8 significantly inhibited both TNF and PC production by LPS-stimulated M phi. Elevating intracellular calcium ([Ca2+]i), using the calcium ionophore, A23187, or thapsigargin alone, did not induce M phi production of TNF but significantly augmented LPS-stimulated TNF production. CONCLUSION: Our results indicate that increased intracellular calcium causing signal transduction activation through the calmodulin pathway is a necessary, but insufficient, component of the LPS signaling in M phi.

Animals↗
PubMed1996

Improvement in the organ donation rate at a large urban trauma center.

OBJECTIVE: To implement and then determine the efficacy of a "hospital development" (HD) plan designed to increase organ donation rates at an urban trauma center. DESIGN/SETTING: Retrospective reviews of all deaths at an urban, level I trauma center for 1991 to 1994. SUBJECTS: Potential organ donors were identified by standardized criteria, and the reasons why potential donors did not become actual organ donors ("nonproductive donors") were categorized. Actual donors were defined as individuals in whom one transplantable organ was recovered. Results also were expressed as percentages of potential donors for each year. Changes in actual donor numbers and in nonproductive donor categories were compared for the "pre-HD" (1991-1992) and "post-HD" (1993-1994) periods. INTERVENTION: The HD plan had six components: identification of key contact individuals, development and modification of relevant hospital policies, improvement in procurement agency visibility in hospital units, education of hospital staff regarding organ donation, institution of early on-site donor evaluations, and provision of feedback to hospital staff about the disposition of potential organ donors. RESULTS: Institution of the HD plan was associated with a highly significantly increase in actual donors for the post-HD period as compared with the pre-HD period (P < .001), and pre-HD and post-HD donor rates were 26.1% and 49.5%, respectively. This increase was due primarily to a marked improvement in hospital staff identification and referral of potential donors (P < .001). CONCLUSIONS: A coordinated plan incorporating continuing staff education, organ donation policy refinement, and increased visibility and availability of organ procurement agency personnel can substantially increase organ donation at an urban trauma center.

Feedback↗
PubMed1996

Limiting computed tomography to patients with peritoneal lavage-positive results reduces cost and unnecessary celiotomies in blunt trauma.

OBJECTIVE: To determine if computed tomographic (CT) scanning can be used to identify patients with blunt trauma, positive results of diagnostic peritoneal lavage (DPL), and a stable hemodynamic status who could be managed safely and cost-effectively without celiotomy. DESIGN: Patients with blunt trauma who required an abdominal evaluation underwent DPL. Patients with a red blood cell count greater than 10(11)/L (10(5)/mm3) on lavage then underwent CT. Patients with solid organ injury alone, as detected on CT scan, were observed; those with evidence of hollow viscus injury underwent celiotomy. RESULTS: Sixty-seven hemodynamically stable patients had a red blood cell count greater than 10(11)/L on DPL; 38 patients underwent subsequent CT scanning, and 29 underwent immediate celiotomy in violation of the protocol. Eleven patients in the protocol group ultimately underwent celiotomy. Overall, there were significantly fewer nontherapeutic celiotomies performed in the protocol group (2/38 vs 9/29, P < .01). There were no deaths in either group. Because DPL is less expensive than CT, limiting CT to patients with DPL-positive results and hemodynamic stability reduced the charges associated with abdominal evaluation by $580,594 over a period of 2 years. CONCLUSION: Limiting CT to the evaluation of patients with DPL-positive results and hemodynamic stability is safe, reduces charges, and results in a lower rate of nontherapeutic celiotomies compared with DPL alone.

Abdominal Injuries↗
PubMed1996

Prostaglandin E2 production by endotoxin-stimulated alveolar macrophages is regulated by phospholipase C pathways.

BACKGROUND: Eicosanoids play an important role in many aspects of systemic inflammatory responses and host defense. Although the synthesis of eicosanoids by different enzymes has been elucidated, the regulatory mechanism of eicosanoid production is not clear. We designed this study to investigate the hypothesis that PGE2 production by endotoxin (lipopolysaccharide; LPS)-stimulated macrophages (MO) is dependent on phospholipase C (PLC) signaling pathways. METHODS: Rabbit alveolar macrophages (MO) were obtained by bronchoalveolar lavage. MO were suspended in RPMI-1640 medium at 1 x 10(6)/mL and were exposed to Escherichia coli LPS (10 ng/mL) +/- various agonists and antagonists of PLC and its secondary messengers. After 24 hours of incubation, prostaglandin E2 (PGE2) production was measured by ELISA. RESULTS: LPS-activated MO produced four times as much PGE2 as did control unstimulated MO. The increase in PGE2 production was inhibited by PLC inhibitors (U73122 or D609) and a low-molecular-weight PLA2 inhibitor, manoalide. An increase in intracellular calcium and activation of both the calmodulin and protein kinase C kinase pathways increase PGE2 production. CONCLUSIONS: PGE2 production is intimately dependent on several phospholipases. Production is not only dependent on low-molecular-weight PLA2 cleavage of arachidonic acid from membrane phospholipids, but also by-products of PLC activation. PLC-dependent intracellular Ca-calmodulin signaling and protein kinase C activation provide significant modulation of PGE2 production.

Animals↗
PubMed1996

Trauma recidivism in the elderly.

BACKGROUND: The incidence of recurrent trauma in the elderly is unknown. This study evaluated the risk of readmission for injury among elderly trauma patients compared with an uninjured geriatric cohort. The effects of age, sex, race, preexisting illness, and ISS on trauma recidivism were determined. METHODS: Population based retrospective cohort analysis of the elderly using administrative data from the Health Care Financing Administration was performed. The measured outcome was trauma admission within 5 years. The injured were identified using hospital discharge data and the Injury Severity Score generated by ICD-Map. The uninjured were identified from Medicare eligibility files. Comorbid illness was assessed using ICD-9CM codes from outpatient and inpatient data files. RESULTS: The injured members of the cohort had increased risk of subsequent new trauma admission (p < 0.001). Increasing Injury Severity Score, age, and comorbid illness are associated with trauma recidivism. CONCLUSION: Trauma in the elderly is recurrent. Further study is required to develop age and injury specific interventions to prevent recurrent injury.

Age Distribution↗
PubMed1996

Effects of supplemental dietary arginine, canola oil, and trace elements on cellular immune function in critically injured patients.

Dietary nutrients may have pharmacological value in modulating the immune system. We studied the effects of two enteral diets, which differed in their content of arginine, fat source, and select trace elements, on immune function in critically injured patients. Leukocytes were isolated from healthy volunteers and severely injured (ISS > 13) patients on the first, sixth, and tenth day of receiving either a standard diet or experimental diet. Monocytes were assayed for tumor necrosis factor, procoagulant activity, and prostaglandin E2 following endotoxin exposure. Neutrophil oxidant production and lymphocyte blastogenesis was assessed. Leukocyte function was uniformly depressed compared to normal patients on day 1. The response of leukocytes from patients receiving experimental diet improved or "normalized" by day 6, while remaining depressed in patients receiving standard diet. Dietary nutrient modification can effect cellular immune responses to inflammatory stimuli in severely injured patients.

Adolescent↗
PubMed1996

Surgical treatment of myasthenia gravis in two major Middle East teaching hospitals: factors influencing outcome.

BACKGROUND: The results of thymectomy on patients with generalised myasthenia gravis have been widely reported. However, there is no information on whether the experience of western countries can be generalised to the population of the Middle East. The purpose of this study was to evaluate the safety and efficacy of thymectomy in patients with myasthenia gravis in a Middle East patient population and to identify clinical and histopathological factors associated with improved long term outcome of surgery. METHODS: In a prospective study, sixty three patients (aged 1.5-51 years) were treated in two university teaching hospitals between 1984 and 1991 and followed up for a mean of four years. Close communication was established with neurologists to obtain early referral. Radical anterior mediastinal dissection through a median sternotomy was performed in all patients. The response was evaluated by modified Osserman's classification. RESULTS: Eighteen patients achieved complete remission and a further 39 improved, producing an overall response rate of 90.5%. Patients with milder disease (stage II) had a higher response rate (97%) than those with more advanced disease (78%). Patients operated on with less than three years of symptoms had a better outcome (94%) than those with longer duration of preoperative symptoms, especially in non-thymomatous patients. Age and sex had no effect on the outcome. There was no effect on response rate if patients had hyperplastic or non-specific thymic histological findings, but patients with thymoma fared worse. CONCLUSIONS: These results are comparable with reports from the western world and represent the first prospective study from the Middle East. Thymectomy is indicated for all patients suffering from generalised myasthenia gravis soon after the diagnosis is made, regardless of age, stage, thymic pathology, and preoperative clinical status.

Adolescent↗
PubMed1996

Assessment of two clinical trials: interferon-gamma therapy in severe injury.

Two recent studies have examined the efficacy of interferon-gamma in reducing infection and death in patients sustaining severe injury. Both included multi-center, randomized, double-blinded placebo-control design. The first trial, conducted at four university trauma centers, enrolled 213 patients, while the second trial involved nine university trauma centers and 416 subjects. Recombinant human interferon-gamma (100 micrograms) was administered subcutaneously daily for 10 days in the first trial and 21 days in the second, in addition to standard supportive therapy. In both trials infection rates were similar in the treatment arms. Although the death rate related to infection was not affected in the first study, the second trial suggested an improved outcome from this complication. The outcome of the larger trial was flawed by dominant findings at one center that had the highest enrollment, infection, and death rates. Confounding variable analysis presented here explains much of the difference between center findings in the larger trial. Thus, the benefit of interferon-gamma as an immune adjuvant in severe injury is clouded by study design flaws evaluating its use and by the inability to identify appropriate subjects using clinical criteria.

Adolescent↗