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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is no disease-specific instrument available for health status assessment in bronchiectasis. We examined the stability, validity and responsiveness of a measure designed for asthma and COPD, the St. George's Respiratory Questionnaire (SGRQ), in this condition. One hundred and eleven patients were studied on 2 separate d 6 mo apart. On both days each patient completed the SGRQ and measures of general and disease-specific health, mood, and fatigue. They also performed a shuttle walking test and comprehensive lung function tests. Repeatability was tested over 2 wk in 23 patients. The intraclass correlation (ri) for the SGRQ Total score was 0.97. The SGRQ component scores correlated well with relevant markers of disease activity. Examples include: SGRQ Symptoms score versus MRC Wheeze score, r = 0.634, p < 0.0001; Activity score versus shuttle walking test, r = -0.659, p < 0.0001; and impacts score versus physical fatigue, r = 0.610, p < 0.0001. Changes in the SGRQ Total score from entry to follow-up also correlated with changes in other measures of the patients' health. There were significant differences in the SGRQ total score between patients who improved and those who deteriorated over the 6 mo in respect to wheeze (F = 5.6, p < 0.01) and breathlessness (F = 6.05, p < 0.01). We conclude that the SGRQ reflects impaired health in bronchiectasis patients.
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PMID:Validation of the St. George's Respiratory Questionnaire in bronchiectasis. 927 36

Inspiratory muscle function has been shown to be related to general muscle weakness, weight loss, blood gas tensions, airway obstruction and hyperinflation. The aim of this study was to define (1) the factor that is the main determinant of the tension-time index of the inspiratory muscles (TTmus), and which this increases the risk of inspiratory muscle fatigue; and (2) whether a breathing strategy is adopted to avoid inspiratory muscle fatigue. Twenty-seven normal volunteers and 35 stable COPD outpatients (FEV1% predicted, range: 21-89%; and FRC/TLC, range: 49-77%) were studied. The TTmus was determined as follows: TTmus = PI/PImax.TI/Ttot, where Pi is the mean inspiratory pressure calculated from the mouth occlusion pressure (P0.1), PImax is the maximal inspiratory pressure, TI is the inspiratory time, and Ttot is the total time of the breathing cycle. COPD patients showed significantly lower PImax and higher P0.1, PI, PI/PImax, and TTmus than normal subjects. No patient had a TTmus value higher than the inspiratory muscle fatigue threshold of 0.33. The FEV1 was significantly correlated with TTmus and all its components in the patients. The FRC/TLC was also correlated with all components except PI. Body weight was only correlated with PImax. In a forward and backward stepwise regression analysis, FEV1 appeared to be the only significant factor explaining the variance of log (PI/PImax) and log (TTmus), whereas FRC/TLC was the principal determinant of PImax. In COPD patients, a non-linear relationship was found between TI and P0.1. A negative linear relationship was found between TI/Ttot and PI/PImax. In conclusion, although hyperinflation predominantly affected inspiratory muscle strength in a group of stable COPD patients with a wide range of severity, airway obstruction was the principal factor determining the magnitude of TTmus. In addition, in order to remain below the inspiratory muscle fatigue threshold, as the severity of airway obstruction increased, patients adopted a breathing strategy characterized by decreased TI/Ttot as inspiratory pressure demand increased.
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PMID:Tension-time index of inspiratory muscles in COPD patients: role of airway obstruction. 985 Mar 66

To determine the extent to which patients with Stage I COPD experience improvements in physical performance and quality of life as a result of exercise training, and to compare these improvements with those seen in Stage I and II patients, 151 patients with COPD underwent a 12-wk exercise program. Outcomes were measured at baseline and follow-up. Physical performance was evaluated by means of a 6-min walk, treadmill time, an overhead task, and a stair climb. General health-related quality of life was assessed in terms of the domains of Social Function, Health Perceptions, and Life Satisfaction. Disease-specific health-related quality of life was assessed with the Chronic Respiratory Disease Questionnaire (CRQ). Six-minute walk distance increased significantly in Stage I (200.5 ft [95% CI: 165.4, 235.7]), Stage II (238.3 ft [143.3, 333.3]), and Stage III (112.1 ft [34.6, 189.6]) participants. Treadmill time increased significantly in Stage I (0.42 min [0.20, 0.64]) and Stage II (0.64 min [0.14, 1.4]) participants. Time to complete the overhead task decreased significantly in Stage I (0.91 s [1.72, 0. 11]) and Stage II (1.39 s [2.66, 0.13]) participants. None of the measures of general health-related quality of life improved in any of the three groups. Participants in Stages I, II, and III all experienced improvements in the CRQ domains of dyspnea (0.72 [0.53, 0.91], 0.47 [0.02, 0.91], and 0.46 [0.05, 0.87], respectively) and fatigue (0.49 [0.33, 0.66], 0.54 [0.20, 0.87], and 0.55 [0.05, 1.05], respectively). These results suggest that all patients with COPD will benefit from exercise rehabilitation. Berry MJ, Rejeski WJ, Adair NE, Zaccaro D. Exercise rehabilitation and chronic obstructive pulmonary disease stage.
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PMID:Exercise rehabilitation and chronic obstructive pulmonary disease stage. 1050 15

The effect of a COPD crisis on arterial blood gases, heart rate, lactate and indices of oxidative stress were investigated before, during and 1 h after a 'run up to fatigue' in 6 COPD horses. They were investigated twice, randomly: once in acute crisis (C) and once in clinical remission (R). Arterial and mixed venous blood samples were collected and analysed for partial pressures in O2 and CO2. The mixed venous blood was also analysed for plasma lactate (LA) and packed cell volume (PCV), as well as for indices of oxidative stress, i.e. reduced glutathione, glutathione disulphide, glutathione redox ratio (GRR) and lipid hydroperoxides (LPH). The exercise test was an effort of increasing intensity on a treadmill at 0% slope, which was stopped when the horses showed signs of exhaustion. Their performance was evaluated by the number of steps and the running time in the last step. Heart rate was monitored continuously during the test. Blood sampling was performed before, just after and 1 h after the end of the test. The COPD crisis significantly reduced the time to fatigue. However, despite the fact that the exercise intensity and length were lower, peak HR and peak LA were similar in C and R, while arterial hypoxaemia and hypercapnia, and PCV were significantly higher in C, indicating a higher physiological stress in this condition. By contrast, the oxidative stress seemed to be higher in R than in C as suggested by the fact that, 1 h after exercise, GRR and LPH were significantly increased with regards to their pre-exercise values in R and not in C. The fact that exercise did not induce an oxidative stress in C could be partly related to (1) the lower exercise intensity reached by the horses, and (2) to the more severe hypoxaemia experienced in this condition. In conclusion, COPD horses in acute crisis show a significant decrease in performance. The reasons for this exercise intolerance remain unclear, but do not appear to be related to any increase of the oxidative stress in C.
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PMID:Cardiorespiratory measurements and indices of oxidative stress in exercising COPD horses. 1065 28

If chronic hypercapnia in patients with severe COPD occurs as a consequence of respiratory muscle (RM) weakness or fatigue, we would expect that ventilatory muscle recruitment (VMR) and exercise performance in stable hypercapnic patients would differ from those in eucapnic patients. We evaluated exercise performance and RM function at rest and during exercise in 19 eucapnic (PCO(2) 40 +/- 3 mm Hg), and 13 hypercapnic (PCO(2) 52 +/- 10 mm Hg) patients with severe COPD. A metabolic cart was used to determine V E, V O(2), V CO(2), and HR. Gastric (Pg) and esophageal (Ppl) balloons were used to measure Pg, Ppl, and Pdi. Ventilatory muscle recruitment pattern (VMR) was partitioned using end-inspiratory and end-expiratory Pg and Ppl. Hypercapnic patients had lower FEV(1) (0.60 +/- 0.24 versus 0.95 +/- 0.31 L, p < 0.001), MVV (28 +/- 11 versus 41 +/- 13 L, p < 0.001), resting PO(2) (61 +/- 11 versus 70 +/- 11 mm Hg, p < 0.001), peak PO(2) (60 +/- 20 versus 75 +/- 22 mm Hg, p < 0.005), and V E(max) (24 +/- 10 versus 32 +/- 12 L/min, p < 0.001). Patients in both groups had similar FRC (5.7 +/- 1.6 versus 5.0 +/- 1.5 L), V O(2)max (0.58 +/- 0.30 versus 0.76 +/- 0.32 L/min), Watts (45 +/- 48 versus 71 +/- 59), V E/MVV (88 +/- 33 versus 79 +/- 14), and HRmax (117 +/- 17 versus 128 +/- 18 beats/min). PI(max) (67 +/- 28 versus 65 +/- 32 cm H(2)O) and PE(max) (98 +/- 34 versus 96 +/- 40 cm H(2)O) were also similar in both groups. VMR (DeltaPg/DeltaPpl) at rest (-0.28 +/- 0.51 versus 0 +/- 0.35) and during exercise (0.4 +/- 0.2 versus 0.39 +/- 0.15) was equally affected in both groups. We conclude that exercise capacity and ventilatory muscle recruitment are similarly impaired in eucapnic and hypercapnic patients with severe COPD. These findings make inability of the lung to increase ventilation and not respiratory muscle dysfunction a more attractive explanation for CO(2) retention in stable hypercapnic patients.
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PMID:Respiratory muscle recruitment and exercise performance in eucapnic and hypercapnic severe chronic obstructive pulmonary disease. 1071 37

Non invasive ventilation refers to the technique of providing ventilatory support without a direct conduit to the airway. It is a promising new technique, which is particularly useful in patients with COPD. Patients with COPD are prone to develop acute exacerbations, which pushes them into acute respiratory failure. Under these circumstances, tracheal intubation and mechanical ventilation is associated with significant morbidity and mortality. A number of well conducted studies support the fact that non invasive positive pressure ventilation (NIPPV) in these circumstances reduces rates of intubation, mortality, complications and duration of hospital stay. The biggest advantage of these techniques is their simplicity, ease of implementation and improved patient comfort allowing them to retain important functions like speech, cough and swallowing. NIPPV should be instituted early in the course of acute respiratory failure due to COPD before irreversible fatigue sets in. The current thinking is that NIPPV rests the respiratory muscles allowing other therapies time to be effective. Facilities for NIPPV should be available in all hospitals admitting patients with respiratory failure. Patients with severe, stable COPD who are hypercapnic and are deteriorating despite maximal conventional treatment should definitely be offered a trial of NIPPV. In such patients NIPPV has been shown to improve quality of life, reverse blood gas abnormalities, improve exercise tolerance and reduce hospital admissions. Physicians must familiarize themselves with this promising new ventilatory technique.
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PMID:Non invasive ventilation in COPD. 1091 75

Diaphragmatic strength, which can be roughly estimated by non invasive techniques such as maximal inspiratory pressure or sniff nasal pressure, is specifically assessed by the measurement of transdiaphragmatic pressure during electric or magnetic phrenic nerve stimulation. However, muscle endurance is probably a more relevant parameter in pulmonary disease. Recent progress in the field of diaphragm biology were mainly obtained in animal models. Data in human disease are currently restricted to COPD and steroid induced myopathy. In COPD patients, recent studies demonstrated significant adaptations of diaphragm fibers susceptible to counterbalance the mechanical disadvantage due to hyperinflation. These changes include an increased proportion of fatigue resistant type I fibers, a decrease in sarcomere length and an increase in mitochondrial density. Regarding corticosteroid induced myopathy, numerous experimental studies are available whereas data are scarce in human disease. Respiratory corticosteroid myopathy is characterized by markedly decreased strength and endurance of inspiratory muscles. Histologic data obtained by quadriceps biopsies in COPD patients demonstrated diffuse fiber atrophy, increased variation in diameter of fibers and diffuse necrotic fibers. Recent data in rats suggest that decreased IGF expression induced by corticosteroids might contribute to diaphragmatic changes.
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PMID:[Clinical investigation of diaphragmatic function. Relationships with the biology of muscle]. 1093 20

Six Warmblood horses suffering an acute exacerbation of COPD were tested to investigate whether inhalation of ipratropium bromide (IB) dry powder (2,400 microg) 30 min preexercise would improve their exercise capacity. A cross-over protocol with an inert powder placebo (P) was used. Mechanics of breathing and arterial blood gases were determined before treatment, after treatment but pre-exercise, and during an incremental exercise test. Oxygen consumption (VO2) was also measured before and during exercise, and the time to fatigue recorded. Inhalation of IB reduced total pulmonary resistance (RL) and maximum intrapleural pressure changes (deltaPpl(max)) and increased dynamic compliance before exercise. The onset of exercise was associated with a marked decrease in RL in P-treated horses but not those receiving IB, so that RL during exercise was not affected by treatment. Although deltaPpl(max) was lower at 8,9 and 10 m/s with IB, there were no treatment-related changes in VO2, blood gases, time to fatigue or any other measurement of breathing mechanics. Therefore, although inhalation of IB prior to exercise may have improved deltaPpl(max), it had no apparent impact on the horses' capacity for exercise.
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PMID:Effects of inhaled ipratropium bromide on breathing mechanics and gas exchange in exercising horses with chronic obstructive pulmonary disease. 1181 50

OBJECTIVES: To examine the levels of life satisfaction for patients with chronic obstructive disease (COPD) and to explore the relationships between life satisfaction, lung function, walking distance test/exercise capacity and quality of life. STUDY DESIGN: The population comprised 91 patients with COPD, 28 patients with COPD using long term oxygen therapy (LTOT) and a reference group (R) of 150 healthy individuals. Before the study, a number of the COPD patients had been tested with regard to spirometry, walking distance and quality of life using the Chronic Respiratory Disease Questionnaire (CRQ). All subjects filled in an eight-item checklist on levels of life satisfaction. RESULTS: Significantly lower levels of satisfaction were reported by both patient groups than the R group for satisfaction with life as a whole and satisfaction derived from vocational/occupational situation, sexual life and ADL, and by the LTOT group, furthermore, also with family life. Only 10% of the patients were satisfied with their health. The LTOT group reported significantly lower levels of satisfaction than the COPD group for life as a whole, satisfaction with their vocational/occupational situation, leisure, ADL situation and their satisfaction with family life and partnership relation. Factor analyses demonstrated different patterns between the R group and the patient group. No correlation was found between satisfaction with life as a whole and lung function parameters whereas three of the CRQ dimensions; emotional function, fatigue and mastery correlateded significicantly with satisfaction with life as a whole and several of the domains. No relationships was found between satisfaction with life as a whole or any of the domains and the CRQ dimension dyspnea. CONCLUSIONS: The low levels of satisfaction with life as a whole, in addition to low levels of satisfaction with several domains, indicate that the majority of the patients had not managed to cope successfully with the consequences of their impairment. More attention must, thus, be given to these patients in the rehabilitation work.
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PMID:Life satisfaction in subjects with chronic obstructive pulmonary disease. 1244 24

V(A)/Q mismatching and load/capacity imbalance are the major physiologic determinants of chronic respiratory failure. The former underlies lung failure and the consequent development of hypoxemia. The latter causes chronic ventilatory failure and hypercapnia. This is the consequence of an inefficient breathing pattern with lower VT and higher respiratory rate, probably due to the "wise choice" of preventing excessive inspiratory effort and eventually respiratory muscle fatigue. In many disorders, V(A)/Q mismatching and the load/capacity imbalance coexist, particularly in COPD, where the interplay between the two pathophysiologically represents the advanced stage of the disease. In other disorders, one of the two mechanisms prevails; for example, V(A)/Q mismatching in pure lung diseases, and chest wall mechanics in thoracic disorders. This has important therapeutic implications because oxygen administration can relieve hypoxemia, whereas mechanical ventilation can prevent excessive hypercapnia and respiratory acidosis. Although the role of oxygen therapy is well established, the role of chronic mechanical ventilation is still a matter of debate, particularly in COPD. A major task for future research is to achieve the best possible understanding of the pathophysiologic factors predisposing to chronic ventilatory failure, to prevent the progression of the respiratory diseases to the stage when chronic respiratory failure eventually develops.
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PMID:Physiologic factors predisposing to chronic respiratory failure. 1248 63


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