Respiratory muscle involvement in multiple sclerosis.
Respiratory complications are common in the terminal stages of multiple sclerosis and contribute to mortality in these patients. When respiratory motor pathways are involved, respiratory muscle weakness frequently occurs. Although it is well established that weakness of the respiratory muscles produces a restrictive ventilatory defect, the degree of muscle weakness and pulmonary function are poorly related. Respiratory muscle weakness was observed in patients with normal or near normal pulmonary function. Expiratory muscle weakness is more prominent than inspiratory muscle weakness and may impair performance of coughing. Subsequently, in addition to bulbar dysfunction, respiratory muscle weakness may contribute to ineffective coughing, pneumonia, and sometimes even acute ventilatory failure may ensue. Respiratory muscle weakness may also occur early in the course of the disease. Recent studies suggest that the respiratory muscles can be trained for both strength and endurance in multiple sclerosis patients. Whether respiratory muscle training delays the development of respiratory dysfunction and subsequently improves exercise capacity and cough efficacy, prevents pulmonary complications or prolongs survival in the long-term remains to be determined. (+info)
The effects of aerosolized dextran in a mouse model of Pseudomonas aeruginosa pulmonary infection.
Airway infections initiated by the interaction of bacterial adhesins with carbohydrate receptors can be potentially prevented by nontoxic carbohydrate inhibitors. Intranasal inoculation of neonatal mice with Pseudomonas aeruginosa PAO1 caused pneumonia in 55% of control mice but in only 13% of mice inoculated 2 h after dextran inhalation (P<.001) and in 28% inoculated 4 h after dextran inhalation (P=.02). PAO1 adherence to epithelial cells was inhibited by 50% in the presence of dextran. Dextran was well distributed throughout the airways and stimulated tumor necrosis factor-alpha production in murine lungs but not interleukin-8 production by human epithelial cell lines. Phagocytosis of PAO1 was not affected by dextran nor was killing by human neutrophils diminished. Administration of dextran by aerosol may prevent murine pneumonia by impeding bacterial access to epithelial receptors and by stimulation of the immune functions of the epithelium. (+info)
Respiratory rehabilitation in chronic obstructive pulmonary disease: predictors of nonadherence.
Rehabilitation is now an integral part of chronic obstructive pulmonary disease (COPD) management. The objective of the study was to determine predictors of nonadherence to a COPD rehabilitation programme. Patients attending a COPD clinic were invited to participate in a 4 week, hospital-based, outpatient, COPD rehabilitation programme conducted predominantly by respiratory physiotherapists. All potential participants undertook an interviewer administered questionnaire addressing social, economic, psychological and healthcare factors, and underwent baseline physiological measures. Subsequently they were classified as: 1) "adherent" group who completed the total programme (n=55) or 2) "nonadherent" group who refused or began but did not complete the programme (n=36). The nonadherent group compared to the adherent group were more likely to be divorced (22 versus 2%, p<0.005), live alone (39 versus 14%, p<0.02), and to live in rented accommodation (31 versus 6%, p<0.005). There were no differences between the two groups in terms of baseline physiological parameters (forced expiratory volume in one second, forced vital capacity, 6-min walk distance, oxygen saturation, perceived dyspnoea), quality of life domains (Chronic Respiratory Disease Questionnaire), or indices of COPD-related morbidity. The nonadherent group were more likely to be current smokers (28 versus 8%, p<0.02) and less likely to use inhaled corticosteroids (16 versus 42%, p<0.005). The nonadherent group was not significantly likely to be depressed, anxious, prone to hyperventilation or to have had previous emotional counselling and was more likely to be dissatisfied with disease-specific social support (51 versus 2%, p<0.001). In conclusion, a substantial proportion of eligible subjects who did not participate in a chronic obstructive pulmonary disease rehabilitation programme were not more physiologically impaired, but were more likely to be: socially isolated, lack chronic obstructive pulmonary disease-related social support, still be smoking and be less compliant with other healthcare activities. Identification of one or more of these factors reliably allows prediction for nonadherence to a rehabilitation programme. (+info)
Physiotherapy and bronchial mucus transport.
Cough and expectoration of mucus are the best-known symptoms in patients with pulmonary disease. The most applied intervention for these symptoms is the use of chest physiotherapy to increase bronchial mucus transport and reduce retention of mucus in the airways. Chest physiotherapy interventions can be evaluated using different outcome variables, such as bronchial mucus transport measurement, measurement of the amount of expectorated mucus, pulmonary function, medication use, frequency of exacerbation and quality of life. Measurement of the transport rate of mucus in the airways using a radioactive tracer appears to be an appropriate outcome variable for short-term studies. Evaluation of chest physiotherapy only with pulmonary function tests appears to be inadequate in short-term studies. The popularity of using pulmonary function tests is probably based more on the availability of the instruments than on a theoretical basis related to the question of chest physiotherapy improving mucus transport. Quality of life and progression of the disease are not often used as outcome variables, but it may be worthwhile to use these in the future. (+info)
Scottish Confidential Inquiry into Asthma Deaths (SCIAD), 1994-6.
BACKGROUND: There have been important changes in the organisation of care for patients with asthma since asthma deaths were studied in the 1980s by the British Thoracic Association (BTA), with greater emphasis on long term control of symptoms and the use of preventive therapy. Recent trends in routine statistics show a decline in population death rates. METHODS: A confidential review was undertaken of general practice and hospital records and interviews with general practitioners of patients dying in mainland Scotland between January 1994 and December 1996 with a principal diagnosis of asthma recorded by the Registrar General's Office. Panel assessment of the cause of death was carried out and a number of possible adverse factors were identified. The data from the 15-64 year age group were compared with similar data from the earlier study by the BTA. RESULTS: Over the three year period 95 deaths of 235 studied (40%) were confirmed as being due to asthma. Taking account of different methods of case ascertainment used in the BTA and this study, a fall in the calculated rate of "deaths assessed as due to asthma" was found from 2.51 (95% CI 2.34 to 2.68) per 100,000 population in 1979 to 1.26 (95% CI 1.19 to 1.33) per 100,000 population in 1994-6. Fewer individual adverse factors were identified in clinical management, with appropriate routine management in 59% and management of the final attack satisfactory in 71%. Patient factors such as poor compliance, lack of peak expiratory flow (PEF) measurements, and overuse of reliever medication without inhaled corticosteroids, and psychosocial problems, notably depression, were confirmed as important contributing factors. Four of five patients under 16 years of age who died were found to have problems with routine management. CONCLUSIONS: This population based study documents important improvements in the standard of asthma care as well as a significant decline in the rate of deaths due to asthma over a period during which the organisation of care has changed and the chronic nature of the disease has been acknowledged. Strategies which might have a further impact include the greater use of PEF recordings, particularly during acute attacks, to document recovery, prescription monitoring of the underuse of inhaled corticosteroids, consideration of the use of combined preparations where persistent overuse of bronchodilators is occurring, and increased input for young patients whose routine management is proving difficult. (+info)
The role of respiratory care practitioners in a changing healthcare system: emerging areas of clinical practice.
OBJECTIVE: To evaluate shifts in respiratory care practice in the context of changing healthcare system and market dynamics. STUDY DESIGN: Telephone survey, structured interview, and case studies. METHODS: We conducted a telephone survey of 471 respiratory care practitioners (RCPs), drawn from the membership database of the American Association for Respiratory Care. We also interviewed 10 employers of RCPs and conducted 2 in-depth case studies to supplement our survey results. We used several statistical techniques to analyze our data, including calculation of population-weighted descriptive statistics and multivariate regression models. RESULTS: Changes in the healthcare system have prompted RCPs to broaden their practice settings, skills, and responsibilities. Respiratory care practitioners are taking part in managed care-related activities, such as cost control and disease management. We found that the need for certain skills and responsibilities varies by practice setting. In our interviews, employers considered RCPs cost effective providers for certain services. CONCLUSIONS: The practice of respiratory care is evolving to meet the changing needs of the healthcare system. A key challenge is to ensure appropriate growth and development of the respiratory care profession, as well as the delivery of appropriate services under new care management settings and processes. (+info)
Collaborative prototyping approaches for ICU decision aid design.
When computer-based aids do not support the human users' decision-making strategies or anticipate the organizational impacts of technological change, advances in information technology may degrade rather than enhance decision-making performance. Such failures suggest the design of human-computer cooperation for problem solving and decision-making must be driven by human cognitive and organizational process requirements rather than computer technology. Decision- and user-centered development techniques involve domain experts and end-users in the earliest phases of design to evolve an understanding of requirements through iterative prototyping. This paper presents a collaborative approach to cognitive systems engineering applied to developing a clinical aid to assist respiratory care in the surgical ICU. (+info)
Effects of graded hyperventilation on cerebral blood flow autoregulation in experimental subarachnoid hemorrhage.
An impaired CBF autoregulation can be restored by hyperventilation at a PaCO2 level of about 2.9 to 4.1 kPa (22 to 31 mm Hg). However, it is uncertain whether the restoring effect can take place at lesser degrees of hypocapnia. In the current study, CBF autoregulation was studied at four PaCO2 levels: 5.33 kPa (40 mm Hg, normoventilation), 4.67 kPa (35 mm Hg, slight hyperventilation), 4.00 kPa (30 mm Hg, moderate hyperventilation), and 3.33 kPa (25 mm Hg, profound hyperventilation). At each PaCO2 level, eight rats 2 days after experimental subarachnoid hemorrhage (SAH) and eight sham-operated controls were studied. The CBF was measured by the intracarotid 133Xe method. The CBF autoregulation was found to be intact in all controls but completely disturbed in the normoventilated SAH rats. However, by slight hyperventilation, CBF autoregulation was restored in seven of eight SAH rats with a decline in CBF of 10%. The CBF autoregulation was found intact in all of the moderately or profoundly hyperventilated SAH rats, whereas the decline in CBF was 21% and 28%, respectively. In conclusion, hyperventilation to a PaCO2 level between 4.00 and 4.67 kPa (30 to 35 mm Hg) appears to be sufficient for reestablishing an impaired autoregulation after SAH. (+info)