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Biomedical subjects

R M Allman

Publications and source records attributed to R M Allman.

At least 55 records · Page 3Linked to original sources
PubMed1981

Pathogenesis of the neurotrophic joint: neurotraumatic vs. neurovascular.

The most widely accepted and propagated theory of neurotrophic joint pathogenesis is the neurotraumatic one. Seldom published and little known is the neurovascular theory. To gain better understanding of the pathogenesis, we reviewed radiographs of 91 neurotrophic joints with attention to the particular joint affected, the type of changes present (resorptive vs. productive), and the time sequence involved. The pathological findings, when available, were also reviewed. While many joint changes could not be explained on a traumatic basis alone, all could be explained by a vascular mechanism.

Arthropathy, Neurogenic↗
PubMed1981

The neuropathic joint: a neurovascular bone disorder.

The pathogenesis of the neuropathic joint has long been a subject of controversy. Two main theories have evolved: (1) the neurotraumatic theory, which states that the changes result from repeated mechanical trauma to a joint that is insensitive to pain, and (2) the neurovascular theory, which states that the changes result from a neurally initiated vascular reflex that leads to hyperemia and very active bone resorption by osteoclasts. Through clinical, radiographic, and pathologic observation, it is evident that both theories play a role. Initially, the alteration of sympathetic control triggers a persistent hyperemia, leading to active bone resorption. There may or may not be secondary pathologic fractures and subsequent repair. This depends upon whether the joint is insensitive and whether it is subjected to continued weight-bearing; if so, then the neurotraumatic mechanism comes into play, but only secondarily.

Arthropathy, Neurogenic↗
PubMed1981

Circulatory patterns of deossification.

Bone is a dynamic organ composed of live tissue and inert substance. Thus, an understanding of bone disease has as its foundation the concept of bone as a highly vascular connective tissue in which different nutritional circulatory fields control the deposit and removal of solids in a balanced field. The article offers an explanation of the vascular components of disease and the correlation of anatomically defined nutritional circulatory fields in order to facilitate the necessary breadth and precision of diagnosis.

Acute Disease↗
PubMed1978

Radiologic-pathologic correlation from the Armed Forces Institute of Pathology. Inflammatory fibroid polyp.

The inflammatory fibroid polyp of the stomach, sometimes called eosinophilic granuloma, is a relatively uncommon lesion usually presenting a solitary, benign-appearing filling defect. The differential diagnoses include polypoid adenocarcinoma, hyperplastic mucosal polyp, adenoma, leiomyoma, epitheliod leiomyoma and leiomyosarcoma, and aberrant pancreas. Although difficult to distinguish by gross morphologic features, the inflammatory fibroid polyp shows a distinctive inflammatory response of the mucosal stroma in which eosinophils may be prominent. It is unrelated to the eosinophilic granuloma of lung or bone.

Adenocarcinoma↗
PubMedDate not supplied

Physical properties of vitamin E oil and silicone oil.

A comparison of the physical properties of vitamin E oil and silicone oil is made. The parameters measured include: viscosity, fluid density, refractive index and wetting characteristics of the water/liquid interface. These properties showed remarkable similarities between vitamin E oil and silicone oil.

Densitometry↗
PubMedDate not supplied

A clinical evaluation of contrast-detail analysis for ultrasound images.

We report on the reproducibility of human observers' vanishing detection thresholds for visual targets in contrast-detail (C/D) analysis of ultrasound B-mode images. The images used in this study contain visual targets which are circular cross sections of constant-contrast conical structures in the C/D phantom. The vanishing threshold diameters for these targets vary as a function of the perceived size of the imaged target, target-to-background contrast, image noise content, and reproducibility of the decision levels of human observers for repeated observations. Our study indicates that the determination of absolute vanishing threshold diameter values for several targets of different contrast by human observers yields a high degree of error that is not predicted by existing theoretical assumptions based on a static threshold detector. We find that systematic error is introduced by the observers during the course of the experiment and that the levels of sensitivity of the observers differ widely at all times, and increase the amount of total observer error. These results suggest that, due to the large total observer error, C/D analysis may be impractical in a clinical environment, unless there is access to a team of observers specifically and extensively trained in this task. We suggest that a computer-based observer may be more reliable for the objective performance of contrast-detail analysis as a method for evaluating ultrasound image quality and comparison of imaging systems.

Humans↗
PubMedDate not supplied

Pressure ulcers, hospital complications, and disease severity: impact on hospital costs and length of stay.

OBJECTIVE: To determine whether or not the development of a Stage II or greater pressure ulcer in-hospital is associated with increased hospital costs and length of stay after adjusting for admission severity of illness, comorbidities, nosocomial infections, and other hospital complications. DESIGN: Prospective, inception cohort study. SETTING: Tertiary care, urban, university teaching hospital. PARTICIPANTS: 286 patients identified within 3 days of admission to a tertiary care, urban teaching hospital were enrolled in a prospective, inception cohort study. Patients were age 55 or greater; expected to be confined to bed or chair or with a hip fracture; and expected to remain in hospital at least 5 days. MEASUREMENTS: Baseline data were collected within 3 days of admission. Weekly skin assessments were performed by study nurses to document the development of pressure ulcers. Medical record reviews, patient exams, and physician and nurse interviews were used to obtain baseline demographic, medical, functional, nutritional, and global measures of disease severity. The incidence of nosocomial infections and the number of other hospital complications were monitored by medical record reviews. Hospital costs were estimated using category-specific cost-to-charge ratios. Diagnostic-related group (DRG) adjusted length of stay was calculated by subtracting the mean length of stay for assigned DRGs from actual stays. RESULTS: Incident pressure ulcers were associated with significantly higher mean unadjusted hospital costs ($37,288 vs $13,924, P = 0.0001) and length of stay (30.4 vs 12.8 days, P = 0.0001). In addition to pressure ulcers, other independent predictors of hospital costs and length of stay after multivariable analyses included: admission to an intensive care unit or surgical service, younger age, nosocomial infection, the physician assessment of disease severity, and the number of other hospital complications. Compared with those who did not develop pressure ulcers, patients who developed pressure ulcers also were more likely to develop nosocomial infections (45.9% [17/37] vs 20.1% [50/249], P = 0.001) and other hospital complications (86.5% [32/37] vs 43.0% [107/249], P < 0.001). After adjusting for only the admission predictors of costs and length of stay by multivariable analyses, hospital costs, and length of stay for those who developed pressure ulcers remained significantly greater than for those who did not develop pressure ulcers ($14,260 vs $12,382, P = 0.03, and 16.9 vs 12.9 days, P = 0.02, respectively). The differences in costs and length of stay for those with and without incident pressure ulcers were even greater when adjusted for admission predictors and also the occurrence of nosocomial infections and other complications ($29,048 vs $13,819, P = 0.002, and 20.9 vs 12.7 days, P = 0.0001, respectively). CONCLUSION: Incident pressure ulcers are associated with substantial and significant increases in hospital costs and length of stay. Nosocomial infections and other hospital complications are additional significant independent predictors of health care utilization among patients at risk for pressure ulcers.

Aged↗
PubMedDate not supplied

Pressure ulcer status and post-discharge health care resource utilization among older adults with activity limitations.

In a prospective cohort study, we evaluated post-discharge health care utilization for patients 65 years of age or older whose activity was limited to bed or chair at the time of hospital admission. Post-discharge health care utilization was compared for those who did and those who did not develop a pressure ulcer during the hospital stay. Resource utilization was assessed using Medicare charges and payments reported for 1 year following the date of discharge. Pressure ulcer status during the index hospitalization was determined by study nurses. Sociodemographic data (age, gender, race, marital status) were recorded from the medical record. During the hospital stay, measures of severity of illness, occurrence of infections and other complications, service type (medical or surgical), ICU admission, and major and minor surgery were documented. At the time of discharge, the primary care nurse noted whether the patient was still confined to bed or chair and whether he or she was discharged to a nursing home. The study patients used substantial health care resources in the year following the index hospitalization, with mean Medicare charges and payments of $24,027 and $11,123, respectively. Eleven percent of the patients had developed pressure ulcers during the index hospitalization. These patients incurred Medicare payments during the 12-month post-discharge period that were, on average, $13 higher per day of follow-up than those of patients who had been at risk for, but did not develop, pressure ulcers during the index hospitalization (p = .02). Multivariate analyses suggested that activity limitation to bed or chair is an independent predictor of Medicare payments post-discharge. The in-hospital development of pressure ulcers is associated with higher daily Medicare payments in the year post-discharge, but this association does not remain statistically significant after adjusting for activity level at the time of hospital discharge.

Activities of Daily Living↗