Biomedical subjects

James F Calvert

Publications and source records attributed to James F Calvert.

5 recordsLinked to original sources

PubMed2006

Hyperkalemia.

Hyperkalemia is a potentially life-threatening metabolic problem caused by inability of the kidneys to excrete potassium, impairment of the mechanisms that move potassium from the circulation into the cells, or a combination of these factors. Acute episodes of hyperkalemia commonly are triggered by the introduction of a medication affecting potassium homeostasis; illness or dehydration also can be triggers. In patients with diabetic nephropathy, hyperkalemia may be caused by the syndrome of hyporeninemic hypoaldosteronism. The presence of typical electrocardiographic changes or a rapid rise in serum potassium indicates that hyperkalemia is potentially life threatening. Urine potassium, creatinine, and osmolarity should be obtained as a first step in determining the cause of hyperkalemia, which directs long-term treatment. Intravenous calcium is effective in reversing electrocardiographic changes and reducing the risk of arrhythmias but does not lower serum potassium. Serum potassium levels can be lowered acutely by using intravenous insulin and glucose, nebulized beta2 agonists, or both. Sodium polystyrene therapy, sometimes with intravenous furosemide and saline, is then initiated to lower total body potassium levels.

Algorithms↗

PubMed2006

Dementia-free survival among centenarians: an evidence-based review.

BACKGROUND: The 2000 U.S. census identified 50,454 Americans older than 100 years (18 per 100,000). Increased longevity is only of benefit if accompanied by the maintenance of physical, social, and cognitive function into advanced age. The goal of this review was to identify research describing centenarians to find the prevalence of dementia-free survival. METHODS: We reviewed 650 publications to find studies that described the prevalence of dementia in centenarians, were community-based, had data that were specific to persons older than 100 years, and were published in peer-reviewed journals. For each study, we identified the prevalence of dementia, the completeness of the sample, the number of study participants, the method used to diagnose dementia, and the duration of the study. RESULTS: We identified 20 research groups from 14 countries with publications meeting our search criteria. The studies showed substantial variation in methods of assessing cognitive status, assuring a complete cohort, and sample size. Few studies reported longitudinal data or attempted diagnosis of the cause of dementia. The prevalence of dementia-free survival past 100 years of age varied between 0 and 50 percent. CONCLUSIONS: The methodology used in studies regarding dementia prevalence among centenarians is sufficiently varied that combination of existing studies into a meta-analysis is not possible. Suggestions for assuring quality in future centenarian research are presented.

Aged, 80 and over↗

PubMed2005

Chronic hepatitis C infection in a rural Medicaid HMO.

CONTEXT: Chronic hepatitis C infection (CHCI) is an increasingly common problem, affecting about 2% of the US population. The cost and complexity of treatment and difficulties in communicating with the infected population are of concern to insurers and health planners. PURPOSE: To describe the clinical features of patients with CHCI in a rural Medicaid-covered population and to describe a method developed for treating CHCI in an underserved rural community. METHODS: We developed a disease management approach to patients with CHCI receiving insurance coverage through a Medicaid HMO in rural Oregon. A locally based multidisciplinary hepatitis committee was formed to develop a management protocol and a process for selecting patients for treatment. The committee met monthly to develop the treatment plan for individual patients. Day-to-day treatment was provided by a nurse under the supervision of the committee. FINDINGS: One hundred forty-three adults with CHCI were identified by their primary care physicians. About half the patients had a type 1 genotype. Treatment with pegylated interferon and ribavirin was completed on 21 persons, 11 (52%) of whom had a virologic cure. Problems with treatment toxicity were common. Patient satisfaction with the treatment by the nurse was high. CONCLUSIONS: CHCI is common in this rural, nonminority Medicaid-insured population. A locally based disease management model was developed that was well received by patients and was successful in delivering a high quality of care for people with CHCI in a rural area.

Adolescent↗

PubMedDate not supplied

Benefits and challenges of research with the oldest old for participants and nurses.

The Klamath Exceptional Aging Project is a longitudinal aging study of people 85 and over, the "oldest old," in rural Oregon. Although conducting research with those 85 and over can be challenging, it is increasingly more important that this group be included in research studies given their importance in society. Benefits for the oldest old participating in research include an opportunity for altruism, productivity, and generativity and the expression of power and control. Benefits for nurses conducting research with this group include gaining a unique understanding of the world of the elderly, the honor of being a confidante for them, and the opportunity to provide truly caring nursing to a vulnerable age group. There is also a great sense of satisfaction in adding to the knowledge base needed to attain successful aging.

Aged↗

PubMedDate not supplied

Patterns of dietary supplement usage in demographically diverse older people.

OBJECTIVE: To analyze dietary supplement usage data from 494 older adults, aged 65 to 101 years. SETTING: Community dwellers living independently of institutionalized care. DESIGN: All dietary supplements, including botanicals, were recorded to aid in assessing the health status of older adults. PARTICIPANTS: 1) 224 individuals enrolled in a study that follows the health of persons 85 years and older (oldest-old) in Klamath County, a non-metropolitan area in southern Oregon; 2) 134 participants of oldest-old age living in the metropolitan Portland area, enrolled in a randomized clinical trial of GBE biloba extract (GBE) for dementia prevention; and 3) 136 participants, ages 65-85 years (young-old), also of the Portland area, enrolled in a study of the effects of yoga and exercise on cognition. MEASUREMENTS: Data verified from labels, not from self-report. RESULTS: Of the participants, 70.6% used dietary supplements. Women took supplements more often than men, and usage decreased with age. A greater percentage, 67.4%, of the non-metropolitan oldest-old took supplements, compared to 56.7% of the metropolitan oldest-old. The greatest usage, 89.7%, was in the metropolitan young-olds. All of these percentages exceed those for comparable age groups in national representative surveys. CONCLUSIONS: Dietary supplement usage by older adults in these studies in Oregon exceeded that in other reports and may reflect high interest in complementary and alternative medicine. This report confirms the results of other studies showing that elderly adults, particularly women, use dietary supplements more than other segments of the US population. Researchers and clinicians should be aware of this pattern and potential conflicts with research design or treatment regimen intended for older people.

Aged↗