UMLS:C0432222 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanisms of exertional dyspnea relief in response to supplemental oxygen (O2) in chronic airflow limitation (CAL) are not precisely known and are likely multifactorial. To explore factors contributing to the relief of dyspnea after oxygen administration, 11 patients with severe CAL (FEV1.0 = 39 +/- 3% predicted, mean +/- SEM) and mild hypoxemia (resting PaO2 = 74 +/- 2 mm Hg) breathed room air (RA) and 60% O2 during exercise at approximately 50% of their maximal incremental exercise capacity. Breathlessness ratings (Borg scale), endurance time, respiratory drive (change in mouth occlusion pressure over the first 0.1 s of inspiration, P0.1), ventilation (VE), breathing pattern, operational lung volumes, gas exchange, and metabolic parameters were compared during RA and 60% O2. PaO2 at exercise cessation during RA and 60% O2 was 65 +/- 3 mm Hg and 226 +/- 12 mm Hg, respectively (p < 0.001). With 60% O2, the mean of individual Borg/time slopes fell significantly (p < 0.05) by 23 +/- 12% and was associated with a 35 +/- 11% increase (p < 0.01) in endurance time (r = -0.64, p < 0.05). During 60% O2, slopes of P0.1 and lactate over time also fell significantly (p < 0.05), whereas delta PaCO2/time did not change significantly. At a standardized time near end-exercise, Borg, VE, and P0.1 changed during 60% O2 by -0.8 +/- 0.3 (p < 0.05), -4.1 +/- 2.0 L/min (p = 0.07), and -1.3 +/- 0.5 cm H2O/s (p < 0.05), respectively. Slopes of Borg/VE, Borg/lactate, and VE/lactate were essentially superimposable during tests on RA and O2: Borg, lactate, and VE all fell proportionally during hyperoxia. In patients with CAL and mild exercise hypoxemia, relief of exertional breathlessness during hyperoxia is explained by reduced ventilatory demand in association with reduced blood lactate levels.
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PMID:Factors contributing to relief of exertional breathlessness during hyperoxia in chronic airflow limitation. 903 90

Although skeletal muscle abnormalities have been described in association with human immunodeficiency virus (HIV), the effects of HIV infection on respiratory muscle function have not been well characterized. We hypothesized that HIV+ individuals may develop respiratory muscle weakness and that respiratory muscle dysfunction may contribute to the unexplained dyspnea that occurs in the setting of HIV. To test this hypothesis we studied maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), inspiratory muscle endurance, and respiratory symptoms in 23 HIV+ male outpatients who had no history of acquired immune deficiency syndrome (AIDS)-related pulmonary complications, with a CD4+ T-lymphocyte count of 331.6 +/- 62.1 (mean +/- SEM). Respiratory muscle endurance was measured with an incremental threshold loading (ITL) protocol. We compared these results to those for 14 HIV- males matched for age and weight. Compared with the controls, HIV+ subjects had a significantly lower mean MIP (98.7 +/- 7.4 versus 121.4 +/- 9.3 cm H2O, p < 0.05) and MEP (115.0 +/- 9.3 versus 152.1 +/- 14.8 cm H2O, p < 0.05). Furthermore, during ITL, the mean load at task failure in the HIV+ group was 295.7 +/- 36.2 g, versus 405.8 +/- 52.2 g in the control group (p < 0.05). In the HIV+ subjects there was no relationship between muscle performance and CD4+ count or azidothymidine (AZT) use. There was, however, a highly significant relationship between respiratory muscle dysfunction and symptoms of dyspnea. We conclude that HIV seropositivity is associated with a decline in respiratory muscle performance. This impairment in respiratory muscle function may contribute to the feeling of breathlessness that has been well described in this patient population.
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PMID:Respiratory muscle dysfunction associated with human immunodeficiency virus infection. 911 90

Eighteen hospitalized patients with severe chronic heart failure (ejection fraction [mean +/- SEM] 21% +/- 1%) underwent 3 weeks of exercise training (interval bicycle ergometer and treadmill walking training exercises) and 3 weeks of activity restriction in a random-order crossover trial. Before and after exercise training and after activity restriction, a 6-minute walking test was performed to determine the maximum distance walked, hemodynamic and cardiopulmonary responses, norepinephrine levels, and ratings of leg fatigue and dyspnea while walking. A ramp test on bicycle ergometer (increments of 12.5 W/min) was performed before and after exercise training and activity restriction to determine peak oxygen uptake. After training, the maximum distance walked was increased by 65% (from 232 +/- 21 m at baseline to 382 +/- 20 m; p < 0.001), whereas after activity restriction (253 +/- 19 m) there was no significant difference compared with baseline. No significant differences in hemodynamic and cardiopulmonary parameters (with the exception of the ventilatory equivalent for carbon dioxide and perceived exertion) or norepinephrine levels were observed during walking tests. Improvement in maximum distance walked correlated significantly with training-induced increase in peak oxygen uptake measured during bicycle ergometry (r = 0.47, p < 0.05). The lower the maximum distance walked at baseline, the more pronounced the training-induced prolongation of maximum distance (r= -0.73; p < 0.001). These data support the value of exercise training in patients with severe chronic heart failure for improving maximum distance walked, as documented by the 6-minute walking test. The impairment of walking test performance during activity restriction suggests a need for long-term exercise training programs.
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PMID:Effects of exercise training and activity restriction on 6-minute walking test performance in patients with chronic heart failure. 912 67

This study analyzes a new exercise training procedure, which includes interval exercise training on cycle ergometer (IntCT) (30-s work phases/60-s recovery phases) and on treadmill (60-s work and recovery phases each). Training was applied for 3 wk in 18 patients with severe chronic heart failure (CHF) ((mean +/- SEM) age 52 +/- 2 yr, ejection fraction 21 +/- 1%). Peak VO2 was increased from 12.2 +/- 0.7 to 14.6 +/- 0.7 ml-kg-1 min-1 owing to training (P < 0.001). A specific steep ramp test (work rate increments 25 W.10 s-1) was developed to derive exercise intensity for work phases in IntCT, which was 50% of the maximum work rate achieved. Steep ramp test was performed at the start of the study to determine the initial training work rate, then weekly to readjust it. Since the maximum work rate achieved from this test increased weekly (144 +/- 10 W -->172 +/- 10 W-->200 +/- 11 W; P < 0.001), the training work rate also increased (72 +/- 4 W-->86 +/- 6 W-->100 +/- 7 W; P < 0.001). Physical responses to IntCT were measured. There was no significant change in heart rate, blood pressure, and ratings of perceived exertion (RPE) using a Borg Scale between the first and the third week of training (heart rate 88 +/- 3 b.min-1; blood pressure 115 +/- 4/80 +/- 2 mm Hg; leg fatigue 12 +/- 1; dyspnea 10 +/- 1). Mean lactate concentration (1.70 +/- 0.09 mmol-1-1) indicated an overall aerobic range of training intensity. When compared with the commonly used intensity level of 75% peak VO2 from an ordinary ramp test (work rate increments 12.5 W.min-1), the performed training work rate was more than doubled (240%; P < 0.0001) while cardiac stress was lower (86%; P < 0.01). Values of norepinephrine and epinephrine as well as of RPE corresponded to those measured at 75% peak VO2. Interval exercise training is thus recommended for selected patients with CHF as it allows intense exercise stimuli on peripheral muscles with minimal cardiac strain. Using a steep ramp test, training work rate can be determined and readjusted weekly during initial training period.
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PMID:Interval training in patients with severe chronic heart failure: analysis and recommendations for exercise procedures. 913 68

Cystic fibrosis (CF) is characterized by chronic lung inflammation leading to airways obstruction. Bronchodilators, particularly short-acting beta2-agonists, are, therefore, often used by CF patients. The aim of this study was to evaluate, prospectively, the effects of the long-acting beta2-agonist salmeterol in adult CF patients. Twenty six patients with CF (10 males and 16 females; mean age (+/-SEM) 28+/-2 yrs) with mild-to-moderate airways obstruction (baseline forced expiratory volume in one second/forced vital capacity (FEV1/FVC) 56+/-2%) were monitored in an open, cross-over trial for 4 weeks by means of peak expiratory flow rates (PEFR), self-recorded symptom scores and body plethysmography. During a 2 week run-in period, all patients continued their treatment, including regular short-acting beta2-agonists. In weeks 3 and 4, short-acting beta2-agonists were replaced by the long-acting beta2-agonist, salmeterol (50 microg b.i.d.). Salmeterol produced a significant increase in PEFR compared to the run-in period (morning 375+/-23 vs 332+/-23 L x min(-1), deltaPEFR +15.1+/-3.1%, p<0.003; evening 384+/-24 vs 349+/-24 L x min(-1), deltaPEFR +11.7+/-2.4%, p<0.04). Similarly, patients reported lower symptom scores, e.g. less dyspnoea during the day, fewer nocturnal awakenings, less intense cough, and fewer unscheduled puffs of short-acting beta2-agonists. Thus, the long-acting beta2-agonist salmeterol provided clinical benefit to a majority of adult cystic fibrosis patients with airways obstruction. These short-term results are promising enough to set up long-term controlled studies.
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PMID:Short-term effects of regular salmeterol treatment on adult cystic fibrosis patients. 938 58

We have intensely followed 45 consecutive women who underwent high-dose chemotherapy (cyclophosphamide/cisplatin/BCNU) and autologous bone marrow transplant (HDC/ABMT) for primary breast cancer with pulmonary function testing and computed tomography at regular intervals up to 126 wk (median follow-up, 72 wk). Our results show a high incidence of interstitial pneumonitis requiring steroids (64%), but no deaths due to pulmonary toxicity. The DL(CO) reaches a nadir of 58.2 +/- SEM 3.4 (expressed as a percent of baseline value) 15-18 wk following HDC/ABMT, and marginally improves with time. To a much lesser extent, vital capacity is reduced with a parallel drop in FEV1, suggesting mild restrictive changes without significant obstruction. Patients who develop pulmonary symptoms of cough or dyspnea have a corresponding significantly greater and earlier decline in DL(CO). Chest computed tomography was neither sensitive nor specific for diagnosing pulmonary toxicity. For patients who received steroids for pulmonary toxicity, there was a subsequent improvement in DL(CO) of 17.1% (p = 0.0001). Because our patients do not fit with the recent definition of idiopathic pulmonary syndrome (IPS), we propose the term delayed pulmonary toxicity syndrome (DPTS) to better describe the milder form of lung toxicity seen in our patient population. We were unable to correlate the severity of DPTS with age, tobacco use, baseline pulmonary function, or systemic exposure to BCNU, cyclophosphamide, or cisplatin. These data suggest that factor(s) other than, or in addition to, chemotherapy systemic exposure can contribute to DPTS. Furthermore, early identification and institution of systemic corticosteroids may improve lung function.
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PMID:Delayed pulmonary toxicity syndrome following high-dose chemotherapy and bone marrow transplantation for breast cancer. 947 74

We studied the impact of a 6-wk supervised, multimodality endurance exercise training program (EXT) on strength and endurance of ventilatory and peripheral muscles in patients with chronic airflow limitation (CAL), and determined whether potential improvements contributed to relief of exertional breathlessness (B) and perceived leg effort/discomfort (LE), respectively. Twenty breathless patients with stable CAL (FEV1 = 41 +/- 3% predicted; mean +/- SEM) were tested at 6-wk intervals at baseline, after a nonintervention control period (pre-EXT), and post-EXT. Measurements included: pulmonary function tests (PFTs), maximal inspiratory/expiratory pressures (MIP, MEP), inspiratory muscle endurance (V(LIM)), quadriceps strength and endurance, exercise endurance, and submaximal cycle exercise with cardioventilatory and symptom responses. Measurements at baseline and pre-EXT were identical. Post-EXT, PFTs did not change; exercise endurance measured on the treadmill, cycle ergometer, arm ergometer, and by 6-min walk distance increased 40 +/- 8%, 43 +/- 10%, 12 +/- 5%, and 34 +/- 9%, respectively (p < 0.05); quadriceps strength increased 21 +/- 5% (p < 0.01); MIP and MEP increased 29 +/- 11% and 27 +/- 11%, respectively (p < 0.05); V(LIM) increased almost threefold (p < 0.05). At isotime near end-exercise, B, LE, carbon dioxide production (VCO2), oxygen consumption (VO2), ventilation, and breathing frequency (F) all fell after EXT (p < 0.05): deltaB correlated with deltaF (r = 0.58, p < 0.01). Increased MIP and V(LIM) did not correlate with improved breathlessness or exercise endurance. Similarly, changes in quadriceps strength and endurance did not correlate with changes in LE or exercise endurance. In conclusion, general nonspecific EXT improved ventilatory and peripheral muscle function in severe CAL, but such improvements did not appear to contribute significantly to reduced exertional symptoms and enhanced exercise performance.
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PMID:General exercise training improves ventilatory and peripheral muscle strength and endurance in chronic airflow limitation. 960 28

This study tested the hypothesis that severity of respiratory disability may affect the outcome of pulmonary rehabilitation. In this randomized, controlled study, 126 patients with chronic obstructive pulmonary disease (COPD) were stratified for dyspnoea using the Medical Research Council (MRC) dyspnoea score into MRC3/4 (Moderate) (n=66) and MRC 5 (Severe) dyspnoeic (n=60) groups. The patients were randomly assigned to an eight week programme of either exercise plus education (Exercise group) or education (Control group). Education and exercise programmes for the moderately dyspnoeic patients were carried out in a hospital outpatient setting. Severely dyspnoeic patients were all treated at home. Those in the Exercise group received an individualized training programme. There was a significant improvement in shuttle walking distance in the moderate dyspnoeic group, who received exercise training; baseline (mean+/-SEM) 191+/-22 m, post-rehabilitation 279+/-22 m (p<0.001). There was no improvement in exercise performance in the severely dyspnoeic patients receiving exercise. Neither group of control patients improved. Health status, assessed by the Total Chronic Respiratory Disease Questionnaire score, increased in the moderately dyspnoeic patients receiving exercise from 80+/-18 to 95+/-17 (p<0.0001) after rehabilitation. Much smaller changes were seen in the other three groups. Improvement in exercise performance and health status in patients with chronic obstructive pulmonary disease after an exercise programme depends on the initial degree of dyspnoea.
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PMID:Randomized controlled trial of pulmonary rehabilitation in severe chronic obstructive pulmonary disease patients, stratified with the MRC dyspnoea scale. 972 86

Changes in lung hyperinflation, dyspnea, and exercise endurance are important outcomes in assessing therapeutic responses in chronic obstructive pulmonary disease (COPD). Therefore, we studied the reproducibility of Borg dyspnea ratings, inspiratory capacity (IC; to monitor lung hyperinflation), and endurance time during constant-load symptom-limited cycle exercise in 29 patients with COPD (FEV1 = 40 +/- 2% predicted; mean +/- SEM). Responsiveness was also studied by determining the acute effects of nebulized 500 micrograms ipratropium bromide (IB) or saline placebo (P) on these measurements. During each of four visits conducted over an 8-wk period, spirometry and exercise testing were performed before and 1 h after receiving IB or P (randomized, double-blinded). Highly reproducible measurements included: endurance time (intraclass correlation R = 0.77, p < 0.0001); Borg ratings and IC at rest, at a standardized exercise time (STD), and at peak exercise (R > 0.6, p < 0.0001); and slopes of Borg ratings over time, oxygen consumption (V O2), and ventilation (R > 0.6, p < 0.0001). Responsiveness was confirmed by finding a significant drug effect for: change (Delta) in endurance time (p = 0.0001); DeltaBorgSTD and DeltaBorg-time slopes (p < 0.05); and DeltaIC at rest, at STD, and at peak exercise (p = 0.0001). With all completed visits, DeltaBorgSTD correlated better with DeltaICSTD than any other resting or exercise parameter (n = 115, r = -0.35, p < 0.001). We concluded that Borg dyspnea ratings, and measurements of IC and endurance time during submaximal cycle exercise testing are highly reproducible and responsive to change in severe COPD.
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PMID:Measurement of symptoms, lung hyperinflation, and endurance during exercise in chronic obstructive pulmonary disease. 981 8

In the present study we compared the ventilatory performance whilst wearing self-contained breathing apparatus (SCBA) during exercise, of a group of male fire-fighters (FF, n = 8), with a matched group of male civilians (CV, n = 7). The mean (SEM) physiological characteristics of the subjects (FF vs CV) were: age 31 (2) years vs 32 (4) years; height 179 (2) cm vs 183 (3) cm, P < 0.05; mass 80 (2) kg vs 84 (3) kg; maximum oxygen uptake 4.52 (0.14) 1 x min(-1) vs 4.39 (0.27) 1 x min(-1). Volunteers performed a 23-minute fire-fighting simulation (Firetest), without and with SCBA (Fire-fighter II, Siebe-Gorman/North Safety, Cheshire, UK). During SCBA wear, the FF group used significantly less air and rated their breathlessness significantly lower than the CV group. The mean tidal volume (V(T)) of the FF group remained constant between non-SCBA and SCBA wear conditions, but the CV group increased their mean V(T) by 18%, (P < 0.01). There were no significant between-group differences during the Firetest in total breath duration, inspiratory or expiratory duration, breathing frequency (fb), or heart rate. These data suggest that the respiratory responses of firefighters while wearing SCBA, which are characterised by increases in (fb) but not V(T), may help to reduce their breathlessness during exercise while wearing SCBA.
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PMID:Do fire-fighters develop specific ventilatory responses in order to cope with exercise whilst wearing self-contained breathing apparatus? 1040 20

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