[Dyspnea and lung function. Results of a multicenter study]. / Dyspnoe und Lungenfunktion. Ergebnisse einer Multicenterstudie.

UNLABELLED: In seven pneumological centres 266 patients with different pneumological diseases were investigated. After having clarified several questions regarding the severity of the dyspnoea, cough intensity and the volume of sputum, as well as basic clinical investigation and after an x-ray of the thorax, the diagnosis was arrived at. Subsequently the lung function investigation with the flow-volume curve (including IVC, FVC, PEF, FEV1, MEF50%) and the body plethysmographic Rt and IGV were carried out. Different quality control procedures at and between the different centres ensured comparable results. All centres agreed to using methods well compatible with each other. The question as to which kind of parameters of lung function would agree best with the amount of the dyspnoea, was resolved. The causes for the large scatter of the results are described. Cough and sputum exercise an influence even on the degree of dyspnoea, but not by deteriorating the lung function. The results are shown for the entire collective (Part I) in respect of the different diagnoses (Part II). With different diagnosis the same significant correlations exist but the curves are positioned at different levels of the coordinate system. CONCLUSION: Significant correlations exist between the dyspnoea scale and function parameters. There are individual differences between the dyspnoea scale and disturbances of the function parameters. Carefully performed lung function analyse definitely important in any case.

[Definition and clinical significance of oscillation parameters (fixed frequency technic)]. / Definition und klinische Bedeutung der Oszillationsparameter (Festfrequenztechnik).

Starting from the polyvalent sense of a limitation of the maximum available respiratory flow there is to be pointed to the necessity of the decentralized measurement of resistance. The instrument IfM E1 permits the use of the simple forced oscillation technique for estimations of ROS and the derived values delta ROS and STAV all over the country. The advanced forced oscillation method, based on the fixed frequency technique, contained the option for estimation of the residual volume and especially the phase-angle. The knowledge of psi, Re and phi can make the oscillatory testing of airways resistance more surely. Taking into consideration the dependence of the phase signal on lung volume can state noninvasive different facts about the compliance of the lung-thoracic-diaphragm system.

[Optimizing monofrequent oscillometry]. / Optimierung der monofrequenten Oszillometrie.

Against the background of the working hypothesis of the 1-parametric Siregnost FD 5 forced oscillation technique-phase angle psi may be invariant in a clinical reference population-the hypothetical straight Ros-P line is in good agreement with the crowd of extremely nonlinear Rre-P-lines only within narrow limits. Neglecting phase angle measurements it might be useful to insert a known linear resistor into the airway to determine the pertaining Rre-P relation. In spite of selective tuning to the oscillation frequency of 10 Hz there is full sensitivity to stationary flow; alinear stationary flow characteristics of resistors can be readily determined by forced oscillation. There is a marked improvement in the P-psi/Rre-phi-evaluating system with respect both to the symmetry of phase angle and unequivocality of pressure when the reference phase angle alpha is shifted from 81 degrees to 0 degrees. Using digital data acquisition and processing, a flexible evaluation technique with monitor-oriented test management, automatical calculation of secondary values and multidimensional presentation of results on a graphical display is provided, which has proved its worth in experimental and clinical-physiological studies.

[Theoretical and experimental studies of the diagnostic relevance and comparability of mechanical oscillation parameters]. / Theoretische und experimentelle Untersuchungen zur diagnostischen Relevanz und Vergleichbarkeit oszillationsmechanischer Parameter.

The practical application of the forced oscillation technique for the analysis of the mechanics of respiration is hampered by the fact that the measured frequency-dependent impedance values R(f) and X(f) cannot be related directly to the parameters airway resistance Raw and pulmonary compliance CL. Furthermore, various derived oscillatory parameters are employed which are not directly comparable even with one another. In order to be able to estimate the diagnostic relevance and comparability of the impedance curves R(f) and X(f), their form-specific characteristics R = R(5)-R(20) and X(5), as also the equipment-specific parameters Ros (Siregnost FD5) and Rfo (custo vit), the relationships of these oscillatory parameters to Raw and CL were simulated in a structural model of the respiratory system, and tested in the real system. It was shown that already from frequencies of f greater than 10Hz upwards, R(f) no longer reacts to an increase in resistance in the peripheral region of the lung, and at 20 Hz indicates only the upper airway component of a global obstruction demonstrated body-plethysmographically with Raw. The diagnostic information on peripheral airway obstruction is contained in both components R(f) and X(f) of the respiratory impedance; with increasing obstruction and increasing frequency, it progressively reverts to the X(f) curve. Therefore, by including X(f) in the resistance evaluation for the parameters Ros and Rfo, the underevaluation of R(f) as compared with Raw can in part be compensated for, although an overe stimation at low Raw values with Ros and a large scatter of the Rfo values in the case of large Raw figures has to be accepted.(ABSTRACT TRUNCATED AT 250 WORDS)

[Practical experiences with 2 oscillatory measuring procedures, Siregnost FD 5 and custo vit, in the assessment of chronic airway obstruction]. / Praktische Erfahrungen mit zwei oszillatorischen Messverfahren, Siregnost FD 5 und custo vit, zur Beurteilung chronischer Atemwegsobstruktionen.

In patients with chronic obstructive airway disease, comparative examinations using body plethysmography were performed with a view to evaluating the effectiveness of two forced oscillation techniques, fixed-frequency and poly-frequency techniques in estimating disorders of respiration mechanics. At slight and moderate elevations in bronchial flow resistance, a better agreement was found between the custo vit resistance figure and body plethysmography. A differentiation of healthy subjects from patients with low-grade obstruction by means of the FD 5, requires the establishment of the phase angle (phi), too, while in the case of the custo vit unit, this is possible by demonstrating the frequency dependence of the impedance. Patients with more severe disease with secondary emphysematous changes, reveal a clear difference between the phase signal (psi) primarily measured on the FD 5, and the phase angle. Forced oscillation usefully supplements spirometery in the respiratory basic diagnostic work-up employed through-out treatment. Fixed-frequency techniques require the determination of the phase angle for assessment of peripheral obstructions; the advantage of the poly-frequency technique can be seen in the largely specific demonstration of the frequency dependency of the resistance.

[Oscillometric differentiation of lung fibrosis and lung emphysema]. / Oszillometrische Differenzierung von Lungenfibrose und Lungenemphysem.

In three groups of healthy subjects and patients with pulmonary fibrosis or pulmonary emphysema, the secondary periodical oscillatory phenomena observed under conditions of normal breathing and a slow VC manoeuvre on the Siregnost FD 5 were broken down into a volume- and a flow-synchronous component, as also a third component with no correlation with either volume or flow, and which can be observed in the primary parameters Ros and psi, as also the secondary parameters Rre and phi. While both fibrotic patients and healthy subjects revealed a volume-inverse phase behaviour, patients with pulmonary emphysema revealed a volume-proportional phase behaviour. This difference in volume dependence is explained by the difference in elastic recoil in patients with fibrosis as compared with those suffering from emphysema, and the associated different influence on the filling of the lungs with air and blood.

[Report of a trial of polyfrequent oscillo-resistometry with the custo vit equipment]. / Erprobungsbericht zur polyfrequenten Oszilloresistometrie mit dem Gerät custo vit.

With the aim of determining the significance of the principle of the multi-frequency forced oscillation technique employed by the custo vit to determine the airway resistance, measurements were performed on a number of test subjects, employing a unit available with three different software modifications. A comparison with the resistance values obtained with other equipment (whole-body plethysmograph, Siregnost FD5), revealed the diagnostic usefulness of the technique of frequency-dependent resistance. It was also confirmed that the phase angles, also obtainable with the custo vit, play a considerable role in the significant differentiation of the degree of obstruction. The differences in comparison with other methods are critically examined, and proposals made for a further improvement of the forced oscillation technique employed by the custo vit.

[Oscillation method in the diagnosis of respiratory function in adults--classification and possibilities for optimization. 1. Basic problems and introduction to the method]. / Die Oszillationsmethode in der Atemfunktionsdiagnostik Erwachsener--Einordnung und Optimierungsmöglichkeiten. 1. Mitteilung: Basisproblematik und Einführung in die Methodik.

There is pointed to the necessity, to clear up pathophysiologically a limitation of the maximum available respiratory volume or flow. The required investigations of breathing mechanics for registering the impedance under quiet breathing and measuring the residual volume are possible with the oscillation method at the base. There are listed the insecurities of the taken parameter with a short description of the basic theory of the oscillation method (fixed frequency technique).

[Oscillation method in the diagnosis of respiratory function in adults--classification and possibilities for optimization. 2. Oscillatory resistance (ROS)]. / Die Oszillationsmethode in der'Atemfunktionsdiagnostik Erwachsener--Einordnung und Optimierungsmöglichkeiten. 2. Mitteilung: Die oszillatorische Resistance (ROS).

The oscillatory resistance (Ros) can be measured routinely by simple set frequency technique under physiological conditions relatively independent of age and cooperation of the examinee. It is as a complex number of the breathing mechanics only relatively comparable with the body plethysmographic resistance. Taking into consideration the dependence on actual lung volume and seriousness of obstruction one can give statements adequately reliable for practice with the help of ROS within a limit from 1 to 10 hPa/l/s. By varying of measuring frequency and reference resistor the estimation of low and middle endobronchial obstructions can be optimized (also without additional measuring of the phase-angle).

[Oscillation method in respiratory function diagnosis of adults--integration and optimizing possibilities. 3. The phase angle]. / Die Oszillationsmethode in der Atemfunktionsdiagnostik Erwachsener--Einordnung und Optimierungsmöglichkeiten. 3. Mitteilung: Der Phasenwinkel.

The importance of the phase angle in oscillatory measurements of resistance depends on the presence or absence of an endobronchial obstruction. In case there is an obstruction, a negative phase angle is first of all an expression of the low compliance of the larger airways and points to an underestimation of the real flow resistance. If there is no obstruction one can state facts about the peripheral compliance, in particular taking into consideration the dependence of the phase signal on actual lung volume. It is recommended to supply the basic ventilation tests with an additional determination of a second angle (beta) from the inspiratory part of the psi/V-curve. That allows to separate normal persons and patients with lung fibrosis and emphysema.

[The oscillation method for the diagnosis of respiratory function of adults--arrangement and possibilities for optimization. 4. The oscillatory residual volume determination (RVOS)]. / Die Oszillationsmethode in der Atemfunktionsdiagnostik Erwachsener-Einordnung und Optimierungsmöglichkeiten. 4. Mitteilung: Die oscillatorische Residualvolumebestimmung (RVOS)

The residual volume can oscillatorily be estimated in an easy way with the help of diving-gas. The oscillatory unit, furnished with a sensor of density, serves as a quick helium-analyser. An overestimation of the residual volume can appear as a result of the high volatility of the used gas, an underestimation can result because of the non-registration of lung parts with entrapped air. Therefore a differentiated interpretation of the curve of wash-in is suggested. Thus a good conformity can be found with the body plethysmographic results also in patients with obstructive airways diseases including persons with disturbances of ventilatory distribution.

[Can oscillatory estimation of airway resistance in chronic obstructive patients be improved by the use of double reference resistance?]. / Kann die oszillatorische Einschätzung des Atemwiderstandes chronisch obstruktiver Patienten durch den Einsatz eines verdoppelten Referenzwiderstandes verbessert werden?

Tests were carried out on the usefulness of doubling the reference resistor during airways resistance measurement by forced oscillation method (set frequency technique). Measurements on 110 random subjects using the standard reference tube (Zo = 10 hPa/1/s) for comparison showed almost identical Ros values using the experimental tube, while the latter gave higher Ros values as obstruction increased. Comparisons with the bodyplethysmographic Rt on 65 patients with a chronic obstructive airways disease yielded a closer approximation to the identity curve from 7.0 hPa/1/s using this modified technique. The practical conclusion is to recommend the use of the double reference resistor for the basic clinical diagnosis of obstructive airways disease, both in quantifying advanced grade obstructions and in assessing the damaged respiratory mechanism in chronically ill patients with pronounced ventilatory resistance.

[Experiences with oscilloresistometry in addition to spirometry in preoperative function diagnosis in the elderly]. / Erfahrungen mit der Oszilloresistometrie in Ergänzung der Spirometrie in der präoperativen Funktionsdiagnostik alter Menschen.

A sample of 57 geriatric surgical patients were investigated with the aim of establishing which additional information the forced oscillation method yields for the assessment of an increased operation risk as compared with spirometry. In addition to the proved diagnosis of a restrictive ventilatory disturbance as causing a limitation of the maximum available respiratory volume, the measuring of the oscillatory resistance makes it possible in particular to prove and quantify the obstruction. Over and above this, the measuring of resistance fluctuation while breathing at rest makes it possible to differentiate a geronto-typical exobronchial component of the obstruction. Conclusions are drawn for the improved care of geriatric surgical patients.

[Value of spirometric, pneumotachographic and oscilloresistometric studies in the functional diagnosis of obstructive respiratory tract diseases]. / Zur Wertigkeit spirometrischer, pneumotachographischer und oszilloresistometrischer Untersuchungen in der funktionellen Basisdiagnostik von obstruktiven Atemwegserkrankungen.

Tests were conducted on 90 smokers and a control group of 20 non-smokers using not only simple spirometry but also pneumotachography and the forced oscillation technique, including flow- and resistance-volume graphs. FEV1 was proved to be a sensitive screening test for early recognition of disfunction in the region of the small airways. 39,5% of the younger light smokers already showed signs of impairment to the breathing mechanics indicating exobronchial obstruction. The heavy, mostly older, smokers frequently showed complex disfunction, and in 55,3% the oscillatory resistance revealed quantifiable endobronchial obstruction. The oscillatory flow-resistance-increase-volume (as a percentage of vital capacity) proved the most sensitive small-airways-test during middle age, permitting significant distinction of smokers from non-smokers up to the age of 55.