[Exercise Testing in Respiratory Medicine - DGP Recommendations]. / Belastungsuntersuchungen in der Pneumologie ­ Empfehlungen der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin e. V.

This document replaces the DGP recommendations published in 1998 and 2013. Based on recent studies and a consensus conference, the indications, choice and performance of the adequate exercise testing method and its necessary technical and staffing setting are discussed. Detailed recommendations are provided: for blood gas analysis and right heart catheterization during exercise, walk tests, spiroergometry, and stress echocardiography. The correct use of different exercise tests is discussed for specific situations in respiratory medicine: exercise induced asthma, obesity, monitoring of rehabilitation or therapeutical interventions, preoperative risk stratification, and evaluation in occupational medicine.

[Positional paper of the German working group "cardiopulmonary exercise testing" to ventilatory and metabolic (lactate) thresholds]. / Ventilatorische und metabolische (Laktat-)Schwellen. Positionspapier der Arbeitsgemeinschaft Spiroergometrie.

Thresholds in cardiopulmonary exercise testing are necessary for the evaluation of motivation and cooperation in exercise, for training programs, in transplant medicine, preoperative evaluation and medical assessments. There is a hardly comprehensible number of terminologies concerning these thresholds and their definitions. This hampers the comparison of protocols and studies and leads to incertainties in terminologies and interpretations of cardiopulmonary exercise tests. Based on literature a definition of thresholds was undertaken. Thresholds should be regarded from a conceptional and an operational (methodological) point of view. The conceptional model means, that there are two ventilatory thresholds (VT1 and VT2) and two metabolic thresholds (lactate threshold [LT] 1 and 2 ). These thresholds are pathophysiologically based. Both threshold concepts determinate the beginning and the end of the aerobic-anaerobic transition. The lactate thresholds determine the metabolic changes, whereas the ventilator thresholds 1 and 2 represent the ventilatory response to the metabolic changes. VT1 represents the subsequent increase of ventilation and CO2-output relative to oxygen uptake as a consequence of an increase of lactate and a necessary lactate buffering. VT2 is characterized by an exceeding of lactate-steady-state, resulting in excess lactate, metabolic acidosis and overproportional rise of ventilation. The operational concept describes the method, which is used for determination of the different lactate and ventilatory thresholds. In a further step this can be completed by indicating the exercise protocol which was applied.

Aerosol-derived airway morphometry (ADAM) in patients with lung emphysema diagnosed by computed tomography--reproducibility, diagnostic information and modelling.

Gravitational deposition of monodisperse particles can be used to determine effective airway diameter (EAD). The aim of our study was to assess intraindividual variability of EAD in healthy subjects and patients with emphysema, to compare EAD in patients with different degree and type of emphysema, and to evaluate whether parametric or model analysis would improve the results. EAD was measured vs volumetric lung depth (LD) in 11 healthy subjects (FEV subset1 107%pred) and 41 patients with emphysema (FEV subset1 60%pred; 8/9/24 mild/moderate/severe, 18/7/16 centriacinar/panacinar/bullous according to HRCT). Repeated measurements in LDs of 6-30% showed coefficients of variation of 7.0-10.4% in healthy subjects and 8.3-11.9% in emphysema. Average EAD in 10-16% LD was increased in emphysema, in particular moderate and severe (p<0.05, each). The slope of EAD in 10-16% LD differed between healthy subjects and emphysema, especially bullous and centriacinar. Patients with severe emphysema also showed a different slope compared to mild emphysema and controls. The parameters of the power function used for data fitting also showed differences between controls and emphysema, as well as between centriacinar vs panacinar and bullous emphysema. In a three-compartment lung model only the diameter of the intermediate compartment was enlarged in emphysema. We conclude that in using aerosol-derived airway morphometry, reproducibility of repeated measurements is acceptable. Average values and slopes of the EAD curve, as well as a power function for data fitting, were sensitive in the detection of type and severity of emphysema. In contrast, application of a lung model did not improve the results.

Factor analysis of changes in dyspnea and lung function parameters after bronchodilation in chronic obstructive pulmonary disease.

Expiratory airway collapse is a characteristic feature in patients with chronic obstructive pulmonary disease (COPD). We hypothesized that this collapse might mask the effects of bronchodilators during forced expiration but not during forced inspiration, and that accordingly, the improvement in forced inspiration and not that in forced expiration with bronchodilator therapy would be related to changes in the perception of dyspnea. In order to investigate this, we conducted lung function measurements, including measurements of forced inspiration and expiration before and 30 min after inhalation of 400 microg salbutamol, in 61 patients with COPD (mean FEV(1): 38. 3 L; range: 12.9 to 79.5% predicted). The change in dyspnea from baseline was assessed with a standard visual analogue scale (VAS) ranging from -100 to +100. To delineate the relationship between parameters, we used the statistical procedure of factor analysis. Salbutamol induced an improvement of 0.16 +/- 0.02 L (mean +/- SD) in FEV(1), 0.36 +/- 0.04 L in forced inspiratory volume in one second (FIV(1)), 0.30 +/- 0.04 L in inspiratory capacity (IC), and -0.34 +/- 0.07 L in intrathoracic gas volume; the mean VAS score was 36.4 +/- 3.2. Factor analysis demonstrated that the reduction in dyspnea at rest was primarily associated with changes in parameters describing forced inspiration and not with those of forced expiration or lung hyperinflation, including IC. Our data indicate that in patients with COPD, the reduction in dyspnea after inhalation of a beta(2)-adrenoreceptor agonist is closely correlated with the change in parameters of forced inspiration, and particularly FIV(1), but not with changes in parameters of forced expiration or lung hyperinflation.

Home-based exercise is capable of preserving hospital-based improvements in severe chronic obstructive pulmonary disease.

We examined the feasibility of home-based walking training to maintain the benefits of a short-term exercise training in patients with severe chronic obstructive pulmonary disease (COPD). After initial recovery from an exacerbation, 46 patients were randomized into a training and a control group, and 30 patients completed the programme (mean +/- SD FEV1, 36 +/- 7% predicted). The training group performed a 10-day walking training programme in the hospital, followed by a 6-month programme of supervised walking training at home, integrated into daily activities. The control group did not have exercise training in the hospital or at home. Until 6 months after discharge, lung function, exercise performance and symptom scores were assessed. Six-minute walking distance in the training group improved from day 1 to day 10 (P<0.001) and this effect was maintained over 6 months (P<0.001). On average, daily walking distance at home was 2308 m and walking was reported on 157 days. Quality of life (QoL) scores changed significantly over 6 months (P<0.001). The control group showed no significant changes in exercise performance or QoL scores throughout the whole study period. Therefore, (i) significant improvements in exercise performance and Chronic Respiratory Disease Questionnaire (CRQ) scores could be achieved after recovery from an exacerbation and (ii) these improvements were maintained after discharge, when supported by a home-based walking training.

Effects of a 5-lipoxygenase inhibitor, ABT-761, on exercise-induced bronchoconstriction and urinary LTE4 in asthmatic patients.

The novel 5-lipoxygenase (5-LO) inhibitor, ABT-761, was investigated for its effect on exercise-induced bronchoconstriction in asthmatic subjects. The relationship between 5-LO inhibition and effects on the response of the airways to exercise was examined. In a double-blind, randomized, crossover clinical trial, 10 patients with mild to moderate persistent asthma (who exhibited a fall in forced expiratory volume in one second (FEV1) > or = 20% following standardized exercise challenge) received 200 mg ABT-761 or matched placebo, orally, 5 h prior to exercise on two study days, 7-10 days apart. Lung function, urinary leukotriene E4 (LTE4) and ex vivo calcium ionophore-stimulated LTB4 release in whole blood were measured prior to dosing, prior to exercise and at various time points up to 4 h post-exercise. The mean (SD) maximal percentage fall in FEV1 after exercise was 27.1 (12)% on placebo and 19.9 (10)% on ABT-761 days, respectively (p<0.05). Post-exercise fall in FEV1 was significantly attenuated at 5, 10, 15 and 30 min after exercise and the mean area under curve, representing the overall effect of exercise from 0-45 min post-challenge, was also significantly attenuated by ABT-761 (p<0.001). Ex vivo LTB4 release was inhibited by more than 80% throughout the 4 h post-exercise period, indicating that 5-LO was extensively inhibited at all time points. Urinary LTE4 in the post-exercise period was significantly lower after ABT-761 day than after placebo (40.1 (17.6) versus 89.8 (58.2) pg x mg creatinine(-1); p<0.05). Inhibition of LTB4 release in ABT-761-treated patients correlated positively with the attenuation of post-exercise FEV1 decline (r=0.711; p<0.05). We conclude that ABT-761 is effective in suppressing exercise-induced bronchoconstriction and that this protection is related quantitatively to the degree of 5-lipoxygenase inhibition.

Exercise training improves recovery in patients with COPD after an acute exacerbation.

Clinical experience suggests that exercise is beneficial for recovery after an acute exacerbation in patients with severe chronic obstructive pulmonary disease (COPD). The aim of this study was to quantify the clinical benefit of exercise in these patients. Twenty-nine inpatients were randomly assigned to a training group (n = 15, FEV1 34% pred) or a control group (n = 14, FEV1 38% pred). On ten consecutive days, patients in the training group performed a 6-min treadmill walking test and, in addition, five walking sessions per day at > or = 75% of the respective treadmill walking distance. Patients in the control group performed only treadmill walking tests on days 1, 5, and 10. To directly compare the possible benefit of exercise training all patients had an exercise test on day 11 at the same work load as on day 1. In the training group, 6-min walking distance increased from 237 to 420 m, in the control group from 230 to 255 m over the 10 day period which was significantly different (P < 0.0001). Minute ventilation and oxygen uptake increased significantly (P < 0.05) in the training but not in the control group. When comparing exercise tests on days 1 and 11, minute ventilation, oxygen uptake, PaCO2, lactic acid concentration, and Borg scale were significantly reduced to achieve the same work load (P < 0.01) only in the training group. Intrathoracic gas volume and residual volume decreased, and FEV1 and vital capacity increased in the training (P < 0.05) but not in the control group. Our data demonstrate that exercise training significantly improves the exercise capacity in patients with severe COPD after an acute exacerbation of their disease.

Effects of a single saturation dive on lung function and exercise performance.

We studied the effects of an experimental saturation dive to 360 and 450 m in a simulation chamber on spirometric lung function, diffusing capacity, pulmonary compliance, and exercise performance in eight professional divers (age 22-40 years). To assess intraindividual variability, all parameters were measured on 2 days before and on 2 consecutive days immediately after the dive. For the group as a whole there was a significant increase in vital capacity and alveolar volume, and a decrease in Krogh factor and specific compliance (P < 0.01). These changes were reduced on the 2nd day after the dive. All subjects showed lowered exercise performance after the dive. Arterial pressure of oxygen and ventilation during exercise increased (P < 0.01), whereas arterial pressure of carbon dioxide, oxygen uptake, and anaerobic threshold decreased (P < 0.01). Exercise parameters showed only a slight trend towards pre-dive values on the 2nd day after a dive. The individual analysis revealed that after the dive two subjects showed a marked decrease in diffusing capacity and a more than average decrease in Krogh factor (TLCO/VA). One of them had signs of mild decompression sickness and the other, signs of pre-existing obstructive airways disease. Our data are compatible with the hypothesis that the effects of a single deep saturation dive on pulmonary function and exercise performance are the results of counteracting mechanisms. We suggest that lung volumes increase due to the enhanced work of breathing during a deep saturation dive and that these changes could mask an impairment in gas exchange. Furthermore, a saturation dive can induce an apparent deterioration of pulmonary function.

Effects of acute passive smoking on exercise-induced bronchoconstriction in asthmatic children.

This study was designed to investigate the acute effects of environmental tobacco smoke (ETS) in children with mild asthma during rest and exercise. We studied 13 children [8 males, 5 females; mean age 10 (range 8-13) yr; mean forced expired volume in 1 s (FEV1) 93% (range 82-108%) of predicted] with exercise-induced bronchoconstriction [46 +/- 4% (SE) fall in FEV1 after exercise during cold air breathing]. Children were exposed to ETS (20 ppm carbon monoxide) or ambient air (AA) for 1 h. During the first 54 min of exposure, children were at rest, and during the last 6 min they exercised on a bicycle ergometer (2 W/kg body wt). Spirometry was performed before and during exposure and after exercise. Respiratory symptoms were recorded before and after exposures. In seven children the experiments with AA and ETS were done in duplicate. FEV1 between 5 and 54 min of exposure at rest decreased by 3.2 +/- 0.8% (SE) during AA and by 7.2 +/- 2.3% during ETS exposure compared with preexposure values; the difference between AA and ETS was statistically significant (P = 0.04). The drop in FEV1 was achieved within 5 min and did not change with ongoing exposure. Analysis of individual data revealed that the mean changes during ETS were mainly effected by three children with a significant fall and one child with a significant improvement in FEV1 (P < 0.05). Maximum postexercise fall of FEV1 was 25 +/- 4% after AA and 24 +/- 3% after ETS, which did not differ significantly. Upper and lower respiratory tract symptoms were not significantly different between exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

[Bronchial hyperreactivity of employees in swine and cattle breeding]. / Bronchiale Hyperreaktivität bei Beschäftigten in der Schweine- und Rinderproduktion.

In order to estimate the frequency of nonspecific bronchial hyperreactivity we investigated 167 pig farmers, 102 cattle breeders and 112 control persons with a bronchial screening test with acetylcholine. We found a significant higher rate of bronchial hyperreactivity in pig farmers (16.2%) versus 7.8% in cattle breeders and 4.3% in control persons. Smokers showed a higher rate of hyperreactivity than non-smokers but non-smoking pig farmers had a higher rate of hyperreactivity (11.5%) than smokers in the control group (4.3%). In farmers with respiratory symptoms we found more positive test-results than in asymptomatic farmers. The results underline our former investigations into health effects on the respiratory system brought about by exposure to live-stock especially in swine confinement buildings.

[Respiratory function disorders caused by agrochemical exposure]. / Respiratorische Funktionsstörungen durch Agrochemikalien-exposition.

With the aim to evaluate possible influences of exposition to agrochemicals upon the respiratory system, the ventilatory parameters VC, FEV1,0, FIV1,0, and the values of PaO2 and PaCO2 were investigated in 93 males professionally exposed to mineral fertilizers, and in 69 males professionally exposed to pesticides--both groups working in agrochemical centres. A control group consisted of 162 males without exposition to agrochemicals. In exposed workers mean values of VC, FEV1,0, and PaO2 were lower (highly significant) compared with the control group. Mean values of FEV1,0, FIV1,0, and PaO2 in workers exposed to mineral fertilizers were in the borderline region. Influences upon the respiratory system should be further investigated with regard to long-term effects and to fitness for the job.

[Epidemiology of chronic non-specific lung disease in persons employed in animal production]. / Untersuchungen zur Epidemiologie der CNSLD an Beschäftigten der Tierproduktion.

In 2,091 agricultural workers (animal production, plant production, agrochemistry) the parameters of ventilatory screening FVC and FEV 1.0 were investigated, completed by determination of PaO2 in 1,324 persons with the intention of making evident differences of pulmonary function for diagnosis between these fields of activity. The persons employed in animal production showed more obstructive disturbances of ventilation and highly significantly lower values of PaO2 than the persons in plant production. The regression-coefficient b1 for the decrease of PaO2 in dependence on the duration of activity was more than double as high in animal production than in plant production. The exposure to organic dust (of irritative, allergenic, infectious, toxic action) must be regarded as the essential etiologic factor in animal production.