摘要:

Intrapulmonary mixing of inert gases of different diffusivity, He and SF6, was studied in 5 healthy subjects before and after bronchoconstriction induced by acetylcholine and in 4 patients with chronic obstructive lung disease by analyzing alveolar plateaus, determined at various breath-holding times, tBH. The following results were obtained: In healthy subjects and in patients the slope of the alveolar plateau – i.e. the partial pressure difference between 750 and 1,250 ml of expirate – decreased for both gases with increasing tBH. In healthy subjects complete mixing within the alveolar space occurred faster for He than for SF6. In the patients the change of the alveolar slope was similar for both gases and no horizontal plateau was attained within the experimental range of tBH. In healthy subjects after bronchoconstriction the behavior of the alveolar plateaus resembled that of the patients. However, the differences between He and SF6 were smaller. From these results we suggest that in healthy subjects efficient mixing of inspired gas with lung gas is brought about by diffusion and convection. After acetylcholine these mechanisms are less effective to overcome the inequalities produced by parallel inhomogeneities. In the patients there is a considerable decrease in overall mixing efficiency, probably due to large diffusional resistance within peripheral lung units, so that convection here is the main mechanism contributing to a flattening of the alveolar pla

ISSN:0025-7931    

DOI:10.1159/000194362

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

A simple 9-min progressive cycle ergometer test revealed exercise-induced bronchospasm in 23 of 29 asthmatic subjects (80%) in terms of a 15% decrement in the isovolume forced expiratory flow rate at 50% of the baseline vital capacity (Vmaxis050%vc)· A similar percentage was detected by the Vmaxiso60%TLC (78%), but that found with the FVC (35%) and FEV1.0 (48%) was somewhat lower. The maximum change of Vmax iso 50%VC following exercise in normal subjects was -5.2 ± 2.1%. The Vmax iso 50%VC thus combines sensitivity with specificity, and seems a very suitable procedure for routine clinical use. Asthmatics showing a positive reaction to this test were distinguished by poor pre-exercise lung functio

ISSN:0025-7931    

DOI:10.1159/000194363

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

14 patients with partially reversible airways obstruction were studied with forced expiratory flows (FEV1, PEFR) and with airway resistance measured by an oscillometric method (Siregnost FD-5) before and after drug-induced changes in airways obstruction. 10 inhaled methacholine to induce bronchoconstriction, and 4 inhaled salbutamol and an additional dose of neosynephrine to induce bronchodilation. Intraindividual changes in resistance (Rosc) measured by the oscillometer with quiet breathing showed a fair significant correlation with changes in FEV1 (r = 0.54, p < 0.05) and changes in PEFR measured by the Wright peak flow meter (r = 0.59, p < 0.05). The present type of oscillator can be used for provocations starting from normal airway resistance but not for measures of treatment effects in markedly obstructive patients

ISSN:0025-7931    

DOI:10.1159/000194364

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

We have measured puff by puff the effect of smoking three brands of cigarettes with different composition on airways resistance (Raw) thoracic gas volume (TGV) and the maximal expiratory flow volume (MEFV) curve. Raw increased significantly with all three brands of cigarettes after one puff. The maximum effect was reached after three puffs. Instantaneous flow at 50% of vital capacity (FEF50) decreased significantly with cigarettes high in nicotine content, but not so after smoking a low nicotine (0.31 mg) cigarette. Instantaneous flow at 75% of vital capacity out (FEF75) increased significantly 30 min after the low nicotine cigarette was smoked. A deep inspiration prior to Raw determination reduced by approximately one third the bronchoconstrictor effect of cigarette smoke. All effects were reversible within 30 min, except the delayed effect of the low nicotine cigarette on the FEF75. We conclude that the probable site of action of tobacco smoke is in the large and central airways. The bronchoconstrictor effect rapidly reaches a plateau. A delayed bronchodilation of the small airways observed after smoking the low nicotine cigarette might represent a response usually masked by other long-acting components in smoke. We suggest that the airway response to tobacco smoke is complex and probably a result of several components present in smoke which still have to be identified

ISSN:0025-7931    

DOI:10.1159/000194365

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The behavior of maximum expiratory flow-volume curves and partial expiratory flow-volume curves with and without volume history of total lung capacity was studied in 11 healthy subjects before and after methacholine inhalation challenge. Flow-volume curves were superimposed at absolute lung volumes by measuring thoracic gas volumes at which inspiratory maneuvers began. The results show that maximum inspiratory effort reduced significantly residual volume, either before or after challenge, while flow rates at 40% of control total lung capacity achieved with partial expiratory flow-volume curves with history of total lung capacity were significantly greater than those without history of maximal inflation. These findings are explained by the stress relaxation as an effect of volume history of total lung capacity and by the appearance of time dependence as an index of inhomogeneity of lung emptying. After methacholine the effects of volume history on maximum flows and residual volume were increased. In conclusion, the results of this study emphasize the probability of errors when only maximum expiratory flow-volume curves are used in assessment of bronchial responses

ISSN:0025-7931    

DOI:10.1159/000194366

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

In 7 healthy males, lung static and quasi-static pressure-volume (QS-PV) curves were measured simultaneously with closing volume by the single breath N2 washout test. Comparison was made of four methods for estimation of the closing pressure (CP) at the onset of phase IV. In the first method the transpulmonary pressure (PL) that directly coincided on the tracing with onset of phase IV was measured, results varied widely with a mean of -1.3 ± 2.2 cm H2O (x ± SD). The second method was to identify on the QS-PV curve the point of transition in the shape of the curve from concavity to convexity. This method yielded a mean CP of 2.8 ± 1.7 cm H2 0.05). The third method was to treat the whole PV curve as an exponential curve, and mathematically extrapolate the curve to a volume corresponding to the onset of phase IV, and calculate PL at this point. This method yielded CP of 2.1 ± 0.76 cm H2O. When the same method was applied to static PV curve, CP was 2.0 ± 0.7 cm H2O. Conformity of CP values obtained using extrapolation methods to those expected from theoretical considerations and from in vitro measurements suggests that the extrapolation methods most likely yield the true PL at the onset of airway cl

ISSN:0025-7931    

DOI:10.1159/000194367

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Two methods for measuring respiratory mechanics by forced oscillations were compared, one using a frequency spectrum of 2–32 Hz produced by a pseudorandom noise generator (PRN), the other (Siregnost FD 5) a constant frequency of 10 Hz. In normals and patients with various lung diseases real part of impedance, Re, and phase angle, ψ, determined at 10 Hz with the two devices correlated well; however, Re measured by Siregnost FD 5 was always higher when compared to PRN. In patients with airway obstruction frequency dependence of resistance and reactance could be shown to be related to the severity of the disease. This important information cannot be obtained by Siregnost FD 5. As Siregnost FD 5 is a simple and reliable method, it is a valuable completion of standard lung function methods. However, for detailed analysis the respiratory system should be investigated at a variety of frequenci

ISSN:0025-7931    

DOI:10.1159/000194368

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The effect of ketotifen on allergic symptoms and parameters of respiratory function were studied in 23 allergic children during a period of 6 months therapy. A reduction in nocturnal dyspnea and dyspnea during exercise was observed in 17 patients. Improvement of the FVC, PEF and FEV1 was detected in 14, 15 and 19 patients, respectively. Following a 4-day treatment with ketotifen, a further 15 patients with allergen-induced bronchospasm were challenged by inhalative provocation test, comparing the protective effects of ketotifen and of DSCG in a randomized double-blind crossover study. 7 of 15 patients showed an improved allergen tolerance to the immediate hypersensitivity with ketotifen and 5 patients with DSCG. A protective effect with respect to the delayed hypersensitivity reaction was observed in 2 of 8 patients with ketotifen and in 1 with DSCG.

ISSN:0025-7931    

DOI:10.1159/000194369

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Fluorimetrically measured serum angiotensin-converting enzyme (ACE) activity was found to be significantly elevated (p < 0.001) in 31 untreated patients with sarcoidosis in comparison to 38 healthy controls, 20 corticosteroid-treated patients with sarcoidosis, 15 subjects with resolved sarcoidosis and 100 patients with other lung diseases. ACE values more than 2 SD above the control mean value were seen in 68% of untreated patients with sarcoidosis, but only in 5% of healthy controls, 7% of patients with tuberculosis, 0% of patients with lung tumors, 9% of patients with bronchial asthma or chronic obstructive pulmonary disease and in 17% of patients with pulmonary fibrosis due to hypersensitivity pneumonitis or diffuse idiopathic fibrosis. Resolution of sarcoidosis, spontaneously or induced by corticosteroid therapy, was accompanied by normalization of serum ACE activity in 18 out of 19 cases. In 7 out of 9 patients without clear-cut clinical improvement, changes of serum activity of ACE were not substantiated. Relapse of sarcoidosis seen in 1 case was associated with a significant increase in ACE levels. Our results suggest that longitudinal studies of serum ACE activity are valuable in assessing the current activity and the course of sarcoidosis. Furthermore, they may contribute to restriction of necessary operative diagnostic procedures.

ISSN:0025-7931    

DOI:10.1159/000194370

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Waldenström’s macroglobulinemia was diagnosed in a patient suffering from recurrent lymphocytic pleurisy. Ultrastructural studies of the pleura showed the features of Lennert’s lymphoplasmacytoid immunocytoma. Computerized assisted tomodensitometry revealed a retroperitoneal growth surrounding the right kidney and squeezing the thoracic lymphatic

ISSN:0025-7931    

DOI:10.1159/000194371

出版商:S. Karger AG    

年代:1981

数据来源: Karger