Driving retirement: the role of the physician.
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Aged↗
Biomedical subjects
David B Carr
Publications and source records attributed to David B Carr.
Geriatric syndromes in elderly patients admitted to an oncology-acute care for elders unit.
PURPOSE: The goal of this study was to characterize an elderly population admitted to a novel Oncology-Acute Care for Elders (OACE) unit, determine the prevalence of functional dependencies and geriatric syndromes, and examine their suitability for an interdisciplinary model of care. PATIENTS AND METHODS: We conducted a retrospective review of 119 patients age 65 years or older who had a primary oncologic or hematologic diagnosis and were admitted to the OACE Unit. Standard geriatric screens were administered to assess mood, functional, and cognitive status. Demographic and medical data were compiled by review of patients' medical records. RESULTS: The mean age of the patients was 74.1 years (standard deviation, 5.9 years). The sample was predominantly white, of equal sex, had limitations in instrumental and basic activities of daily living, and a mean length of stay of 6 days. Geriatric syndromes detected by the OACE interdisciplinary team included cognitive impairment (dementia and/or delirium), depression, weight loss, and use of high-risk medications. Adverse events such as falls, restraint use, and pressure sores were rare. CONCLUSION: In this descriptive study, many older cancer patients were found to have geriatric syndromes by the OACE team and these patients were considered appropriate for an interdisciplinary model of care. Additional studies are needed to compare the outcomes of hospitalized older oncology patients receiving an OACE intervention with those patients receiving usual care.
Activities of Daily Living↗
Older adult drivers with cognitive impairment.
As the number of drivers with cognitive impairment increases, family physicians are more likely to become involved in decisions about cessation of driving privileges in older patients. Physicians who care for cognitively impaired older adults should routinely ask about driving status. In patients who continue to drive, physicians should assess pertinent cognitive domains, determine the severity and etiology of the dementia, and screen for risky driving behaviors. Cognitive impairment detected by office-based tests may indicate that the patient is at risk of a motor vehicle crash. Referral for performance-based road testing may further clarify risk and assist in making driving recommendations. Physicians should assist families in the difficult process of driving cessation, including providing information about Web sites and other resources and clarifying the appropriate state regulations. Some states require reporting of specific medical conditions to their departments of motor vehicles.
Adult↗
A quality improvement study on calcium and vitamin D supplementation in long-term care.
OBJECTIVES: The objectives of this study were to evaluate the impact of a quality improvement (QI) study on improving calcium and vitamin D supplementation in a long-term care setting. DESIGN: Retrospective chart review. SETTING: An academic long-term care facility that specializes in dementia care in St Louis, MO. PARTICIPANTS: Participants consisted of 83 long-term care residents. INTERVENTION: The quality improvement team created an educational letter that was signed by the medical director and sent to the facilities' primary care physicians. This letter provided clinicians with the rationale and method to achieve adequate calcium supplementation, assess vitamin D status, and provide adequate vitamin D supplementation in our long-term care setting. Following the letter, the facility pharmacist reviewed the orders during monthly medication reviews and faxed requests to the primary care physicians for appropriate supplements or laboratory tests when necessary. MEASUREMENTS: We reviewed the charts for the presence of calcium supplementation orders, vitamin D levels, and vitamin D supplementation before and after our QI intervention. RESULTS: Of the 83 resident charts that were reviewed, only 37 (44.6%) had calcium supplementation, 19 (22.8%) had assessment of their vitamin D status, and 29 (34.9%) had ongoing vitamin D supplementation prior to implementation of the study. After the QI intervention, calcium supplementation was present in 66 residents (79.5%), vitamin D status had been assessed in 61 residents (73.4%), and vitamin D supplementation had been initiated in 65 residents (78.3%). These changes were statistically significant (P < .05). CONCLUSION: A quality improvement project that used an educational letter from the medical director combined with a medication and laboratory review by the pharmacist was able to increase the number of residents in our long-term care setting with calcium supplementation, increase the number of residents who had vitamin D status assessed, identify many residents with low vitamin D levels, and increase supplementation of vitamin D when indicated.
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Driving and dementia in older adults: Implementation and evaluation of a continuing education project.
PURPOSE: We aimed to develop and evaluate a multimedia workshop curriculum to educate physicians and other health professionals about (a) driving-related assessment in older adults with dementia, and (b) strategies to encourage driving retirement for impaired individuals. DESIGN AND METHODS: A curriculum developed by the Older Drivers Project of the American Medical Association was expanded for presentation by a multidisciplinary team. One pilot and seven test workshops were offered. A program evaluation method-testing knowledge, confidence, attitudes, and practice behaviors-was employed at four points in time: T1 (Time 1; pretest focusing on the previous 12 months), T2 (Time 2; same-day post-test), T3 (Time 3; post-test at 3 months), and T4 (Time 4; post-test at 12 months). RESULTS: At T1, participants (N = 147) expressed high agreement that an assessment of driving ability is an important issue in clinical dementia care, but they reported low knowledge of assessment strategies, resources, and state reporting requirements. Modest gains in knowledge and confidence were demonstrated at both T3 (n = 93) and T4 (n = 63). In addition, the frequency of driving-related practice behaviors (i.e., incorporation of driving-related questions into clinical evaluation, chart documentation, reporting of impaired drivers) had increased significantly by T3 and T4. IMPLICATIONS: The results indicate that a focused workshop curriculum, with practical and immediate applications to care, can motivate measurable changes in clinical practice. Once they are informed, health professionals can address issues of driving ability in older patients with dementia and, with the support of available resources, encourage impaired individuals to retire from driving for the safety of everyone on the road.
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Characteristics of frail older adult drivers.
OBJECTIVES: To determine the prevalence of driving in older adults with mild to moderate physical frailty and to compare characteristics of current frail older adult drivers with those of former drivers in the sample. DESIGN: Retrospective study of frail older adults enrolled in randomized trials of exercise and hormone replacement therapy. SETTING: Urban, academic medical center. PARTICIPANTS: One hundred eighty-three sedentary community-dwelling men and women aged 75 and older with mild to moderate physical frailty, as defined by two of the following three criteria: modified Physical Performance Test (PPT) score between 18 and 32, peak oxygen uptake (VO2) between 10 and 18 mL/kg per minute, and self-report of difficulty or assistance with one activity of daily living (ADL) or two instrumental ADLs. Participants were classified as current or former drivers. MEASUREMENTS: Demographic characteristics, medical diagnoses, medication use, modified PPT score, and psychometric tests. RESULTS: The majority (85%) of the participants were drivers. Former drivers were more likely to be older, be female, reside in congregate independent living for the elderly, have a higher incidence of arthritis and congestive heart failure, take sedating medications, have lower total ADL scores, have lower VO2 peak scores, and have more impairment on tests of cognition and physical strength, although only age, type of residence, and grip strength were independent predictors of driving cessation in the regression analysis. CONCLUSION: Despite the presence of physical frailty, many older adults choose to continue to drive. Further studies are needed to better understand the driving behaviors of frail older adults and explore opportunities for optimizing driving abilities.
Activities of Daily Living↗
Dendritic excitability of mouse frontal cortex pyramidal neurons is shaped by the interaction among HCN, Kir2, and Kleak channels.
Dendritically placed, voltage-sensitive ion channels are key regulators of neuronal synaptic integration. In several cell types, hyperpolarization/cyclic nucleotide gated (HCN) cation channels figure prominently in dendritic mechanisms controlling the temporal summation of excitatory synaptic events. In prefrontal cortex, the sustained activity of pyramidal neurons in working memory tasks is thought to depend on the temporal summation of dendritic excitatory inputs. Yet we know little about how this is accomplished in these neurons and whether HCN channels play a role. To gain a better understanding of this process, layer V-VI pyramidal neurons in slices of mouse prelimbic and infralimbic cortex were studied. Somatic voltage-clamp experiments revealed the presence of rapidly activating and deactivating cationic currents attributable to HCN1/HCN2 channels. These channels were open at the resting membrane potential and had an apparent half-activation voltage near -90 mV. In the same voltage range, K+ currents attributable to Kir2.2/2.3 and K+-selective leak (Kleak) channels were prominent. Computer simulations grounded in the biophysical measurements suggested a dynamic interaction among Kir2, Kleak, and HCN channel currents in shaping membrane potential and the temporal integration of synaptic potentials. This inference was corroborated by experiment. Blockade of Kir2/Kleak channels caused neurons to depolarize, leading to the deactivation of HCN channels, the initiation of regular spiking (4-5 Hz), and enhanced temporal summation of EPSPs. These studies show that HCN channels are key regulators of synaptic integration in prefrontal pyramidal neurons but that their functional contribution is dependent on a partnership with Kir2 and Kleak channels.
Animals↗
Driving and dementia of the Alzheimer type: beliefs and cessation strategies among stakeholders.
PURPOSE: Although driving by persons with Alzheimer's disease (AD) is an important public health concern, we know little about the attitudes and perceptions of key stakeholders regarding driving safety in these individuals or the factors that precipitate and influence driving assessment and cessation decisions. DESIGN AND METHODS: We convened 10 focus groups composed of persons intimately involved in driving decisions for older adults to identify and compare beliefs and perceptions concerning AD and driving and to identify effective strategies to limit or cease unsafe driving. The 68 focus-group participants included health professionals, transportation and law-enforcement professionals, current and former drivers with AD, and family caregivers of current and former drivers with the disease. RESULTS: With few exceptions, participants said that a diagnosis of very mild AD alone did not preclude driving. Most regarded family members as pivotal in monitoring and managing unsafe driving and recognized their need for institutional and medical support, especially support from physicians in counseling and evaluation of health-related fitness of older drivers. Members of each group acknowledged their own roles and responsibilities in driving decisions and described difficulties they experienced in making assessments and implementing decisions to limit or stop the driving of given individuals with AD. IMPLICATIONS: Education of families, professionals, and transportation specialists is needed to understand the influence of AD severity on driving abilities, identify problem driving behaviors, make appropriate referrals of unsafe drivers, and access available resources for drivers with AD and those most responsible for their safety.
Accidents, Traffic↗
Driving cessation in older adults with dementia of the Alzheimer's type.
The psychometric profile of 143 drivers with dementia who stopped driving did not differ from that of 58 individuals with dementia of similar severity who still drove. The reasons given for driving cessation by drivers with dementia as reported by a collateral source are reported.
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Commentary: The role of the emergency physician in older driver safety.
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Accident Prevention↗
Physician's guide to assessing and counseling older drivers.
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Nutrition in the elderly.
PURPOSE OF REVIEW: The purpose of this review is to summarize the most recent clinical trials addressing nutritional issues in the older adult. We specifically focused on clinical trials during the past year from September 2002 to September 2003. RECENT FINDINGS: Obesity in the elderly is increasing in prevalence, along with concomitant macro- and micronutrient deficiencies. Specific food choices (fish, nuts, legumes) may enhance the nutritional status of older adults. Micronutrient deficiencies have been associated with cognitive impairment. Diets based on complex carbohydrates, fibers, red wine, fresh fruit and vegetables, and nonanimal fat may protect against age-related cognitive impairment and dementia. Supplementation with vitamin D at specific doses appears to reduce the risk of fracture, whereas excess supplementation with vitamin A may increase fracture risk. Antioxidant therapy may slow the progression of age-related cataracts. Structured mechanisms for providing nutritional supplements to hospitalized elders increases total energy intake. SUMMARY: Micronutrient deficiencies are common and supplementation appears to improve outcomes. Geriatric obesity will grow to epidemic proportions in the next few decades. Additional research is needed to guide supplementation recommendations and prevent malnutrition in a growing elderly population.
Journal Article↗
Older driver safety: a report from the older drivers project.
Older driver safety is a growing public health concern for which interventions are currently being sought. Statistics show that older drivers suffer a disproportionately high rate of motor vehicle fatalities compared with other adult drivers. This disproportion is due to two factors: an increased crash rate per vehicle mile driven and an increased risk of fatality in the event of a crash. Traditionally, traffic safety efforts for the older population have focused on methods to identify unsafe drivers to enforce driving cessation, but driving cessation deprives the majority of older Americans of their primary form of transportation and has been associated with an increase in depressive symptoms. In response to these concerns, the Older Drivers Project, created by the American Medical Association in partnership with the National Highway Traffic Safety Administration, describes and advocates a more acceptable approach to traffic safety. The primary objective of this approach involves helping older drivers stay on the road safely to preserve their mobility and independence. This can be accomplished through three methods: (1) optimizing the driver, (2) optimizing the driving environment, and (3) optimizing the vehicle. In this approach, driving cessation is recommended only after the safety of the driver cannot be secured through any other means.
Accidents, Traffic↗
Transmitter modulation of slow, activity-dependent alterations in sodium channel availability endows neurons with a novel form of cellular plasticity.
Voltage-gated Na+ channels are major targets of G protein-coupled receptor (GPCR)-initiated signaling cascades. These cascades act principally through protein kinase-mediated phosphorylation of the channel alpha subunit. Phosphorylation reduces Na+ channel availability in most instances without producing major alterations of fast channel gating. The nature of this change in availability is poorly understood. The results described here show that both GPCR- and protein kinase-dependent reductions in Na+ channel availability are mediated by a slow, voltage-dependent process with striking similarity to slow inactivation, an intrinsic gating mechanism of Na+ channels. This process is strictly associated with neuronal activity and develops over seconds, endowing neurons with a novel form of cellular plasticity shaping synaptic integration, dendritic electrogenesis, and repetitive discharge.
Animals↗
Longitudinal driving performance in early-stage dementia of the Alzheimer type.
OBJECTIVES: To longitudinally assess on-road driving performance in healthy older adults and those with early-stage dementia of the Alzheimer type (DAT). DESIGN: A prospective longitudinal study. SETTING: Large urban medical center and surrounding area. PARTICIPANTS: A sample of 58 healthy controls, 21 participants with very mild DAT, and 29 participants with mild DAT participated. DAT was diagnosed using validated clinical diagnostic criteria and staged according to the Clinical Dementia Rating (CDR) Scale. MEASUREMENTS: Healthy controls and individuals with very mild DAT and mild DAT were administered a standardized on-road driving assessment over repeated times of testing. RESULTS: Subjects in the CDR=1 group (mild DAT) had a faster rate of receiving a rating of not safe on the driving test than subjects in the CDR=0 group (healthy controls; log rank test, P=.006), and the survival function of the CDR=0.5 group (very mild DAT) fell between those of the CDR=0 and CDR=1 groups. A Cox proportional hazards model indicated a significant difference in survival functions between the CDR=0 and CDR=1 groups after baseline age was controlled for (P<.001). Cox regression analysis also indicated that baseline age was a significant risk factor for a rating of "not safe" (P=.002). CONCLUSION: This study provides longitudinal evidence for a decline in driving performance over time, primarily in early-stage DAT, and supports the need not only for driving assessments, but also for reevaluation of individuals with very mild and mild DAT.
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Anatomical substrates for glutamate-dopamine interactions: evidence for specificity of connections and extrasynaptic actions.
For normal regulation of motor, affective, and cognitive functions, dopamine provides an essential modulation of glutamate transmission within multiple brain regions. This paper will review three principal anatomical substrates for such interactions. First, dopamine modulates the activity of glutamate neurons within the cerebral cortex. Evidence will be reviewed for dopamine regulation of pyramidal neurons in the prefrontal cortex via synaptic and extrasynaptic mechanisms and through indirect effects mediated by GABA cells. Second, glutamate neurons innervate dopamine cells within the ventral tegmental area. Evidence will be described for selective glutamate input from the prefrontal cortex or the brain stem tegmentum to different populations of dopamine cells. The third level of interaction occurs within target regions via convergent synaptic or extrasynaptic regulation of common neurons. Such convergence will be reviewed for the basal ganglia, prefrontal cortex, and amygdala. Together, these substrates for glutamate-dopamine interactions provide several mechanisms for normal regulation of brain function. Sites of modulatory interaction between dopamine and glutamate also suggest circuit alterations that might contribute to the pathophysiology of mental health disorders and provide potential sites for therapeutic intervention in these conditions.
Amygdala↗
Serotonin receptor activation inhibits sodium current and dendritic excitability in prefrontal cortex via a protein kinase C-dependent mechanism.
The serotonin (5-HT) innervation of the prefrontal cortex (PFC) exerts a powerful modulatory influence on neuronal activity in this cortical region, although the mechanisms through which 5-HT modulates cellular activity are unclear. Voltage-dependent Na+ channels are one potential target of 5-HT receptor signaling that have wide-ranging effects on activity. Molecular and electrophysiological studies were used to test this potential linkage. Single cell RT-PCR profiling revealed that the vast majority of pyramidal neurons expressed detectable levels of 5-HT2a and/or 5-HT2c receptor mRNA with half of the cells expressing both mRNAs. Whole-cell voltage-clamp recordings of dissociated pyramidal neurons showed that 5-HT2a/c receptor activation reduced rapidly inactivating Na+ currents by reducing maximal current amplitude and shifting fast inactivation voltage dependence. These effects were mediated by G(q) activation of phospholipase C, leading to activation of protein kinase C (PKC). 5-HT2a/c receptor stimulation also reduced the amplitude of persistent Na+ current without altering its activation voltage dependence. This modulation was also mediated by PKC. Although 5-HT(2a,c) receptor activation did not affect somatic action potentials of layer V pyramidal neurons in PFC slices, it did reduce the amplitude of action potentials backpropagating into the apical dendrite. These findings show that 5-HT2a,c receptor activation reduces dendritic excitability and may negatively modulate activity-dependent dendritic synaptic plasticity.
Action Potentials↗
Selective prefrontal cortex inputs to dopamine cells: implications for schizophrenia.
Dopamine (DA) neurons in the substantia nigra (SN) and ventral tegmental area (VTA) form several projection systems with diverse functions, such as motor planning through the striatum, reward seeking via the nucleus accumbens (NAc), and cognitive control through the prefrontal cortex (PFC). Disruptions in DA cell activity profoundly impair these functions and contribute to serious clinical conditions such as Parkinson's disease and schizophrenia. DA neurons have been extensively investigated in studies detailing their anatomy, physiology, and neurochemical regulation. Moreoever, recordings from behaving animals suggest that phasic changes in DA cell firing signal expectancy or attentional shifts associated with approach/avoidance behavior. These ideas raise interesting questions regarding how DA neurons are regulated to produce such phasic signals. For example, it is not yet known how different classes of DA projection neurons are regulated by specific inputs. In the first study of its kind within the VTA, our laboratory recently demonstrated that excitatory inputs from the PFC synapse selectively onto DA neurons that project back to the PFC but not onto DA cells that project to the NAc. These findings may explain some of the unique functional properties of mesoprefrontal DA neurons. Moreover, the results are important for understanding the pathophysiology of mental disorders such as schizophrenia.
Cognition↗