Biomedical subjects

Greg Maislin

Publications and source records attributed to Greg Maislin.

15 recordsLinked to original sources

PubMed2003

Human diaphragm remodeling associated with chronic obstructive pulmonary disease: clinical implications.

Diaphragm remodeling associated with chronic obstructive pulmonary disease (COPD) consists of a fast-to-slow fiber type transformation as well as adaptations within each fiber type. To try to explain disparate findings in the literature regarding the relationship between fiber type proportions and FEV1, we obtained costal diaphragm biopsies on 40 subjects whose FEV1 ranged from 118 to 16% of the predicted normal value. First, we noted that our exponential regression model indicated that changes in FEV1 can account for 72% of the variation in the proportion of Type I fibers. Second, to assess the impact of COPD on diaphragm force generation, we measured maximal specific force generated by single permeabilized fibers prepared from the diaphragms of two patients with normal pulmonary function tests and two patients with severe COPD. We noted that fibers prepared from the diaphragms of severe COPD patients generated a lower specific force than control fibers (p < 0.001) and Type I fibers generated a lower specific force than Type II fibers (p < 0.001). Our finding of an exponential relationship between the proportion of Type I fibers and FEV1 accounts for discrepancies in the literature. Moreover, our single-fiber results suggest that COPD-associated diaphragm remodeling decreases diaphragmatic force generation by adaptations within each fiber type as well as by fiber type transformations.

Adaptation, Physiological↗

PubMed2003

Identification of upper airway anatomic risk factors for obstructive sleep apnea with volumetric magnetic resonance imaging.

We used sophisticated volumetric analysis techniques with magnetic resonance imaging in a case-control design to study the upper airway soft tissue structures in 48 control subjects (apnea-hypopnea index, 2.0 +/- 1.6 events/hour) and 48 patients with sleep apnea (apnea-hypopnea index, 43.8 +/- 25.4 events/hour). Our design used exact matching on sex and ethnicity, frequency matching on age, and statistical control for craniofacial size and visceral neck fat. The data support our a priori hypotheses that the volume of the soft tissue structures surrounding the upper airway is enlarged in patients with sleep apnea and that this enlargement is a significant risk factor for sleep apnea. After covariate adjustments the volume of the lateral pharyngeal walls (p < 0.0001), tongue (p < 0.0001), and total soft tissue (p < 0.0001) was significantly larger in subjects with sleep apnea than in normal subjects. These data also demonstrated, after covariate adjustments, significantly increased risk of sleep apnea the larger the volume of the tongue, lateral pharyngeal walls, and total soft tissue: (1) total lateral pharyngeal wall (odds ratio [OR], 6.01; 95% confidence interval [CI], 2.62-17.14); (2) total tongue (OR, 4.66; 95% CI, 2.31-10.95); and (3) total soft tissue (OR, 6.95; 95% CI, 3.08-19.11). In a multivariable logistic regression analysis the volume of the tongue and lateral walls was shown to independently increase the risk of sleep apnea.

Adult↗

PubMed2003

The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation.

OBJECTIVES: To inform the debate over whether human sleep can be chronically reduced without consequences, we conducted a dose-response chronic sleep restriction experiment in which waking neurobehavioral and sleep physiological functions were monitored and compared to those for total sleep deprivation. DESIGN: The chronic sleep restriction experiment involved randomization to one of three sleep doses (4 h, 6 h, or 8 h time in bed per night), which were maintained for 14 consecutive days. The total sleep deprivation experiment involved 3 nights without sleep (0 h time in bed). Each study also involved 3 baseline (pre-deprivation) days and 3 recovery days. SETTING: Both experiments were conducted under standardized laboratory conditions with continuous behavioral, physiological and medical monitoring. PARTICIPANTS: A total of n = 48 healthy adults (ages 21-38) participated in the experiments. INTERVENTIONS: Noctumal sleep periods were restricted to 8 h, 6 h or 4 h per day for 14 days, or to 0 h for 3 days. All other sleep was prohibited. RESULTS: Chronic restriction of sleep periods to 4 h or 6 h per night over 14 consecutive days resulted in significant cumulative, dose-dependent deficits in cognitive performance on all tasks. Subjective sleepiness ratings showed an acute response to sleep restriction but only small further increases on subsequent days, and did not significantly differentiate the 6 h and 4 h conditions. Polysomnographic variables and delta power in the non-REM sleep EEG-a putative marker of sleep homeostasis--displayed an acute response to sleep restriction with negligible further changes across the 14 restricted nights. Comparison of chronic sleep restriction to total sleep deprivation showed that the latter resulted in disproportionately large waking neurobehavioral and sleep delta power responses relative to how much sleep was lost. A statistical model revealed that, regardless of the mode of sleep deprivation, lapses in behavioral alertness were near-linearly related to the cumulative duration of wakefulness in excess of 15.84 h (s.e. 0.73 h). CONCLUSIONS: Since chronic restriction of sleep to 6 h or less per night produced cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation, it appears that even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults. Sleepiness ratings suggest that subjects were largely unaware of these increasing cognitive deficits, which may explain why the impact of chronic sleep restriction on waking cognitive functions is often assumed to be benign. Physiological sleep responses to chronic restriction did not mirror waking neurobehavioral responses, but cumulative wakefulness in excess of a 15.84 h predicted performance lapses across all four experimental conditions. This suggests that sleep debt is perhaps best understood as resulting in additional wakefulness that has a neurobiological "cost" which accumulates over time.

Adult↗

PubMed2003

Risks of acute hospital transfer and mortality during stroke rehabilitation.

OBJECTIVE: To identify demographic, medical, and functional factors associated with transfer of stroke patients to acute hospital services and/or mortality during stroke rehabilitation. DESIGN: Two case-control studies in which logistic regression was used to control for clinical traits associated with differences in likelihood. SETTING: A total of 542 US inpatient and rehabilitation units. PARTICIPANTS: A total of 64,471 patients discharged during 1995. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Transfer to an acute hospital service and death. RESULTS: There were 5847 (9.1%) acute hospital transfers and 320 (0.5%) deaths. Greater disability at admission was associated with higher odds of both acute hospitalization and mortality. Cardiopulmonary arrest, chest pain, gastrointestinal problems, bleeding disorders, hypercoagulable states, and acute renal difficulties increased the relative odds of acute hospitalization from 3.1 (95% confidence interval [CI], 2.3-4.2) to 12.7 (95% CI, 9.2-17.6). The likelihood of mortality for patients 85 years of age or older was more than 2-fold (2.5; 95% CI, 1.7-3.6) that of patients 65 years of age or younger for blacks, it was nearly 2-fold (1.7; 95% CI, 1.3-2.3) compared with whites, after adjusting for clinical differences. CONCLUSION: Higher likelihoods of mortality among older patients versus younger, black patients versus white, and patients with more rather than less disability at admission suggest the need for greater vigilance in monitoring medical status.

Activities of Daily Living↗

PubMed2003

Organizational characteristics and restraint use for hospitalized nursing home residents.

OBJECTIVES: To examine the effect of organizational characteristics on physical restraint use for hospitalized nursing home residents. DESIGN: Secondary analysis of data obtained between 1994 to 1997 in a prospective phase lag design experiment using an advanced practice nurse (APN) intervention aimed at reducing physical restraint for a group of hospitalized nursing home residents. SETTING: Eleven medical and surgical units in one 600-bed teaching hospital. PARTICIPANTS: One hundred seventy-four nursing home residents aged 61 to 100, hospitalized for a total of 1,085 days. MEASUREMENTS: Physical restraint use, APN intervention, age, perceived fall risk, behavioral phenomena, perceived treatment interference, mental state, severity of illness, day of week, patient-registered nurse (RN) ratio, patient-total nursing staff ratio, and skill mix. RESULTS: Controlling for the APN intervention, age, and patient behavioral characteristics (all of which increased the likelihood of restraint use), weekend days as an organizational characteristic significantly increased the odds of restraint (weekend day and patient-RN ratio on physical restraint use: odds ratio (OR) = 1.92, 95% confidence interval (CI) = 1.38-2.68, P <.001; weekend day and patient-total staff ratio on physical restraint use: OR = 1.91, 95% CI = 1.37-2.66, P <.001; weekend day and skill mix on physical restraint use: OR = 1.91, 95% CI = 1.37-2.67, P <.001). CONCLUSION: Key findings suggest that organization of hospital care on weekends and patient characteristics that affect communication ability, such as severely impaired mental state, English as a second language, sedation, and sensory-perceptual losses, may be overlooked variables in restraint use.

Aged↗

PubMed2003

Staging functional independence validity and applications.

OBJECTIVES: To establish construct and predictive validity of the activities of daily living, sphincter-management, mobility, and executive-function (ASME) staging system of functional independence and to describe potential applications. DESIGN: National data were used to validate the stages. Sensitivity to functional change was addressed by comparing patients' stages at discharge to their stages at admission. Construct validity was assessed by examining stage distribution differences among groups of patients classified by impairment category. Predictive validity was determined by the degree to which high stages at admission predict discharge to the community and low stages at admission predict serious morbidity or mortality. SETTING: Inpatient rehabilitation facilities. PARTICIPANTS: Data from 231,686 individuals discharged from 560 US inpatient rehabilitation facilities in 1995. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Stage at rehabilitation discharge, community discharge, acute hospital discharge, or death while in rehabilitation. RESULTS: More than 90% of patients were discharged at a higher stage in at least 1 domain while not declining in any other domain. The odds (95% confidence interval) of community discharge for patients admitted at the highest compared with the lowest stage varied from 2.1 (1.9-2.2) to 3.1 (2.9-3.2), depending on the domain. The odds of acute hospitalization or death were reduced at the highest stages, compared with the lowest, by a factor ranging from .33 (.22-.49) to .65 (.61-.69). CONCLUSIONS: The ASME stages appear valid and sensitive to change. Functional Independence Staging (FIS) has relevance in establishing prognoses and in selecting among therapeutic modalities. FIS will facilitate the identification of meaningful functional goals and interpretable clinical trial endpoints. One of its most important applications could be in the establishment of outcome indicators for quality monitoring under the prospective payment system.

Activities of Daily Living↗

PubMed2003

Functional independence staging: conceptual foundation, face validity, and empirical derivation.

OBJECTIVE: To develop a staging system for functional independence across the activities of daily living (ADLs), sphincter-management, mobility, and executive-function domains (ASME) for the FIM instrument that is consistent with the International Classification of Functioning, Disability and Health. DESIGN: National data were used to define the stages. We searched for the most likely configurations of item scores that increased ability to perform component activities in each domain by approximately 1 level per item per stage. SETTING: Inpatient rehabilitation facilities. PARTICIPANTS: Data from 218,290 people discharged from 560 US inpatient rehabilitation facilities in 1995. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Activity profiles formed from FIM scores. RESULTS: Seven stages were defined separately for each ASME domain. Stages approximate the average amount of effort expended by the patient when performing the component activities included in a domain, beginning with less than 25% of effort at the lowest total assistance (stage 1) and ending with 100% effort at the highest complete independence (stage 7). Consistent with developmental principles, independence is achieved at lower stages in the most fundamental activities of eating, transfers, and communication. Recovery of independence in the more difficult activities of bathing, stair climbing, and problem solving does not occur until the higher stages are reached. The degree of independence is described with a shorthand abbreviation of the domains followed by the stage the patient has reached in each domain. For example, ASME 5,1,6,7 indicates need for supervision in the ADLs (A-5), total assistance in sphincter management (S-1), modified independence in mobility (M-6), and complete independence in executive functions (E-7). CONCLUSIONS: ASME stages serve as a common language and shorthand for expressing the functional consequences of illness and injury, while complementing information about impairment and diagnosis, thereby facilitating communication, assessment, and goal setting in terms that are meaningful to patients and their care givers.

Activities of Daily Living↗

PubMed2003

A method for measuring quality of life through subjective weighting of functional status.

OBJECTIVE: To apply a new tool to understand the quality of life (QOL) implications of patients' functional status. DESIGN: Results from the Features-Resource Trade-Off Game were used to form utility weights by ranking functional activities by the relative value of achieving independence in each activity compared with all other component activities. The utility weights were combined with patients' actual levels of performance across the same activities to produce QOL-weighted functional status scores and to form "value rulers" to order activities by perceived importance. SETTING: Persons with severe disabilities living in the community and clinicians practicing in various rehabilitation disciplines. PARTICIPANTS: Two panels of 5 consumers with disabilities and 2 panels of 5 rehabilitation clinicians. INTERVENTIONS: The 4 panels played the Features Resource Trade-Off Game by using the FIMT(TM) instrument definitions. MAIN OUTCOME MEASURES: Utility weights for each of the 18 FIM items, QOL-weighted FIM scores, and value rulers. RESULTS: All 4 panels valued the achievement of independence in cognitive and communication activities more than independence in physical activities. Consequently, the unweighted FIM scores of patients who have severe physical disabilities but relatively intact cognitive skills will underestimate QOL, while inflating QOL in those with low levels of independence in cognition and communication but higher physical function. CONCLUSION: Independence in some activities is more valued than in others; thus, 2 people with the same numeric functional status score could experience very different QOL. QOL-weighted functional status scores translate objectively measured functional status into its subjective meaning. This new technology for measuring subjective function-related QOL has a variety of applications to clinical, educational, and research practices.

Activities of Daily Living↗

PubMed2002

A novel volumetric magnetic resonance imaging paradigm to study upper airway anatomy.

STUDY OBJECTIVES: We utilized novel three-dimensional volumetric analysis techniques with magnetic resonance imaging (MRI) to study the upper airway and surrounding soft-tissue structures. These MRI techniques allowed us to objectively quantify the volume of the tongue, soft palate, parapharyngeal fat pads, and lateral pharyngeal walls. DESIGN: We first validated our volumetric imaging techniques on a phantom and then demonstrated that our results were reliable and reproducible in normal subjects who did not lose weight. Finally, we studied 12 obese, nonapneic women during wakefulness before and after weight loss. We hypothesized that our novel magnetic-resonance computer-reconstruction techniques would allow us to detect small reductions in the volume of the tongue, soft palate, lateral pharyngeal walls, and parapharyngeal fat pads and increases in the volume of the upper airway with weight loss. SETTING: University medical center. PARTICIPANTS: Normal controls and 12 obese nonapneic women. INTERVENTIONS: Weight loss. MEASUREMENTS AND RESULTS: Following a mean 17.1+/-8.62 kg (17.3%) reduction in weight, upper airway volume increased (p = 0.06) in both the retropalatal and retroglossal regions. This increase in upper airway volume was mediated by significant reductions in the volume of the lateral pharyngeal wall (p = 0.0001) and parapharyngeal fat pads (p = 0.001). However, the volume of the tongue (p = 0.35) and soft palate (p = 0.39) were not reduced significantly with weight loss. CONCLUSIONS: These data indicate that volumetric MRI is a powerful tool to study anatomic changes in the upper airway and surrounding soft-tissue structures and is sensitive enough to detect changes in these structures.

Adipose Tissue↗

PubMed2002

Linear dimensions of the upper airway structure during development: assessment by magnetic resonance imaging.

The upper airway undergoes progressive changes during childhood. Using magnetic resonance imaging (MRI), we studied the growth relationships of the tissues surrounding the upper airway (bone and soft tissues) in 92 normal children (47% males; range, 1 to 11 yr) who underwent brain MRI. None had symptoms of sleep-disordered breathing or conditions that impacted on their upper airway. MRI was performed under sedation. Sequential T1-weighted spin echo sagittal and axial sections were obtained and analyzed on a computer. We measured lower face skeletal growth along the midsagittal and axial oropharyngeal planes. In the midsagittal plane the mental spine-clivus distance related linearly to age (r = 0.86, p < 0.001). Along this axis, the dimensions of tongue, soft palate, nasopharyngeal airway, and adenoid increased with age and maintained constant proportion to the mental spine-clivus distance. Similarly, a linear relationship was noted for mandibular growth measured along the intermandibular line on the axial plane and age (r = 0.78, p < 0.001). In addition, the intertonsillar, tonsils, parapharyngeal fat pads, and pterygoids widths maintained constant proportion to intermandibular width with age. We conclude that the lower face skeleton grows linearly along the sagittal and axial planes from the first to the eleventh year. Our data indicate that soft tissues, including tonsils and adenoid, surrounding the upper airway grow proportionally to the skeletal structures during the same time period.

Adenoids↗

PubMed2002

The National Regional Advisory Council practice survey for 2000.

A practice survey for the year 2000 was conducted through the National Regional Advisory Council. Each respondent was asked to supply detailed information on diagnostic and therapeutic procedures in the first 20 consecutive patients seen in that year with follow-up for 1 year or until an ongoing pregnancy was reached. The results show interesting patterns of geographic differences in treatment of the infertile couple. In general, American Society for Reproductive Medicine guidelines for practice were followed.

Adolescent↗

PubMed2002

Side rail use and bed-related fall outcomes among nursing home residents.

OBJECTIVES: To analyze the effect of physical restraint reduction on nighttime side rail use and to examine the relationship between bilateral side rail use and bed-related falls/injuries among nursing home residents. DESIGN: Secondary analysis of data collected in a longitudinal, prospective clinical trial designed to reduce restraint use. SETTING: Three nonprofit nursing homes. PARTICIPANTS: To examine the first question regarding the effect of physical restraint reduction on side rail usage, we included all nursing home residents who survived a 1-year data collection period (n = 463). To answer the second research question concerning the relationship between side rail status and bed-related falls, subjects' side rail status for each of the four data collection periods was compared. The sample for this analysis includes only those with consistent side rail status (n = 319) for the four observations periods: either 0/1 side rail (n = 188) or 2 (bilateral) side rails (n = 131). MEASUREMENTS: Side rail and restraint status was directly observed by two research assistants, twice each night shift (10 p.m.-6 a.m.) for three nights at each of four data collection points. Nighttime fall-related outcome data were obtained from a review of nursing home incident reports during the entire 1-year data collection period (T1 through T4). Cognitive status was measured using the Folstein Mini-Mental State Examination. Functional and behavioral status was obtained using subscales of the Psychogeriatric Dependency Rating Scale. RESULTS: Over a 1-year period, there was an increase in the proportion of bilateral side rail use for all three nursing homes. Based on the multiple logistic regression analysis, there was no indication of a decreased risk of falls or recurrent falls with bilateral side rail use, controlling for cognition and functional and behavioral status (adjusted odds ratio (AOR) = 1.13, 95% confidence interval (CI) = 0.45,2.03). Similarly, bilateral side rail use did not reduce the risk of recurrent falls, controlling for cognition and functional status (AOR = 1.25, 95% CI = 0.33,4.67). CONCLUSION: Despite high usage of bilateral side rails, they do not appear to significantly reduce the likelihood of falls, recurrent falls, or serious injuries. Bed-related falls remain clinically challenging. The data from this study, coupled with increasing reports of side rail-related injuries and deaths, compel us to seek and empirically test alternative interventions to prevent bed-related falls.

Accidental Falls↗

PubMed2002

Advance care planning and end-of-life care for hospitalized nursing home residents.

OBJECTIVES: To describe advance care planning (ACP) and end-of-life care for nursing home residents who are hospitalized in the last 6 weeks of life. DESIGN: Constant comparative analysis of deceased nursing home resident cases. SETTING: A not-for-profit Jewish nursing home. PARTICIPANTS: Forty-three deceased residents hospitalized within the last 6 weeks of life at a tertiary medical center. MEASUREMENTS: Trained nurse reviewers abstracted data from nursing home records and gerontological advanced practice nurse field notes. Clinical and outcome data from the original study were used to describe the sample. Data were analyzed using the constant comparative method and validated in interviews with a gerontological advanced practice nurse and social worker. RESULTS: The analysis revealed distinct characteristics and identifiable transition points in ACP and end-of-life care with frail nursing home residents. ACP was addressed by social workers as part of the nursing home admission process, focused primarily on cardiopulmonary resuscitation preference, and reviewed only after the crisis of acute illness and hospitalization. Advance directive forms specifying preferences or limitations for life-sustaining treatment contained inconsistent language and vague conditions for implementation. ACP review generally resulted in gradual limitation of life-sustaining treatment. Transition points included nursing home admission, acute illness or hospitalization, and decline toward death. Relatively few nursing home residents received hospice services, with most hospice referrals and palliative care treatment delayed until the week before death. Most residents in this sample died without family present and with little documented evidence of pain or symptom management. CONCLUSION: Limiting discussion of advance care plans to cardiopulmonary resuscitation falsely dichotomized and oversimplified the choices about medical treatment and care at end-of-life, especially palliative care alternatives, for these older nursing home residents. Formal hospice services were underutilized, and palliative care efforts by nursing home staff were often inconsistent with accepted standards. These results reinforce the need for research and program initiatives in long-term care to improve and facilitate individualized ACP and palliative care at end of life.

Advance Directives↗

PubMed2002

Risperidone treatment in children and adolescents with autism: short- and long-term safety and effectiveness.

OBJECTIVE: Atypical neuroleptics, including risperidone, are used to treat children with autism, despite limited efficacy and safety data. Many clinicians believe that risperidone will not induce dyskinesias in children. The authors investigated open risperidone treatment in children with autism and included findings on dyskinesias. METHOD: The sample included 22 outpatients (mean age = 7.1 years) diagnosed with autism (DSM-IV). Treatment consisted of a 1-month short-term phase followed by a 6-month long-term phase. At the end of the long-term phase, drug was discontinued, and the need for further drug treatment and the occurrence of withdrawal dyskinesias were assessed. Measures included the Clinical Global Impressions (CGI), Children's Psychiatric Rating Scale (CPRS), and the Abnormal Involuntary Movement Scale. RESULTS: The mean risperidone dosage was 1.2 mg/day. Overall, the children had significant clinical improvement as assessed by the CPRS and CGI. Untoward effects included sedation, increased appetite, and weight gain. Two of 13 (15.4%) children treated long-term developed mild, reversible withdrawal dyskinesias when risperidone was discontinued. No child developed dyskinesias on risperidone. CONCLUSIONS: Risperidone shows promise as a treatment in autism. However, withdrawal dyskinesias were noted. Further assessment of the risk of risperidone-related dyskinesias is indicated.

Adolescent↗

PubMedDate not supplied

A psychometric evaluation of the Cornell Scale for Depression in Dementia in a frail, nursing home population.

OBJECTIVE: The authors conducted a psychometric evaluation of the Cornell Scale for Depression in Dementia (CSDD) through factor analysis and assessment of criterion validity in an older, frail nursing home population, with a secondary analysis of pre-intervention data from a longitudinal clinical trial aimed at reducing restraints in nursing homes. METHODS: The sample for the present study was 642 nursing home residents (mean [SD] age 84.3 [7.6] years; range: 61-105; 82% women) with completed CSDD scores, who were interviewed immediately before the intervention. Nursing home residents' scores from the 19-item CSDD were subjected to exploratory factor analysis and criterion-validity analysis. RESULTS: The factor analysis resulted in four distinct clinically interpretable domains: Depression, Somatic/Vegetative, Disturbed Sleep, and Anxiety. Sixteen items were retained in these domains, and summated score indices and a global score were constructed. The global score and the four indices demonstrated adequate internal consistency and reliability. The indices generated by the factor analysis correlated as expected with criterion variables. CONCLUSION: Results suggest that in frail, institutionalized older adults with high rates of dementia, medical illness, and functional disability, depression measurement methods that are less dependent on items highly sensitive to comorbid conditions and not necessarily associated with depression may be more appropriate. Authors recommend further validity testing of the CSDD with similar populations of frail, institutionalized older adults.

Aged↗