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The direct method of chest percussion, first described by Auenbrugger but disseminated by Corvisart, has rapidly been replaced by the indirect or digitodigital method. Chest percussion has not been evaluated by modern acoustic means, so that our present knowledge of the method does not consistently differ from the 19th century approach. Auscultatory percussion is not superior to conventional percussion.

BACKGROUND--The use of lung sound monitoring during bronchial provocation testing has not been clearly demonstrated. The appearance of wheeze and changes in inspiratory breath sound intensity have been analysed and related to changes in spirometric parameters and to airways hyperresponsiveness. METHODS--Lung sounds were recorded in 38 patients undergoing a routine carbachol airway challenge (CAC) test. Spirometric testing was performed before and after the inhalation of each of five cumulative doses of 320 micrograms carbachol; a fall in forced expiratory volume in one second (FEV1) by 20% or more was considered as significant. Lung sound analysis was carried out using a computerised system. RESULTS--The CAC test was positive (CAC+) in 21 patients and negative (CAC-) in 17. At the final stage of the challenge, wheeze was identified in 10 positive patients (48%) and in one negative patient (6%); in non-wheezers the inspiratory breath sound intensity decreased significantly from baseline in 11 CAC+ patients (mean (SD) change -35 (24%)) but not in 16 CAC- patients (mean (SD) change 5 (24%)). In all non-wheezers a linear relationship was found between breath sound intensity and the squared inspiratory airflow (r = 0.53-0.92) which became looser after the inhalation of carbachol. CONCLUSION--When unertaking bronchial provocation testing the accurate identification of wheeze may prove useful in avoiding or shortening the test because of the presumed relationship between wheeze and airways hyperresponsiveness. Changes in breath sound intensity may also be useful, but further studies are required to define the threshold for significant changes in this index.

Our goal was to assess the relation between dust exposure levels and the respiratory health status of workers in grain and flour mills in eastern France. We studied 118 male workers from 11 mills and 164 unexposed male controls. Dust concentration was measured by personal sampling methods. Outcome variables included respiratory symptoms, routine pulmonary function tests, and indices of airway responsiveness to methacholine. A great within- and between-area variability of inhalable dust concentration was found in all mills. A dose-response relationship was observed between dust exposure levels and chronic respiratory symptoms, suggesting that exposure to grain and flour dust may lead to chronic bronchitis. A significant relation was found between dust exposure and airway hyper-responsiveness; this finding is important since it has been hypothesized that the latter abnormality may lead to or be a predisposing factor in subsequent chronic, irreversible airflow obstruction.

We examined the possibility that cyclic gas exchange between alveolar space and the surrounding tissue, induced by alveolar pressure variations, could interfere with plethysmographic measurements of thoracic gas volume (TGV). A model study suggested that TGV could be overestimated by up to 100 ml and that the phenomenon could account for some of its previously reported negative frequency dependence (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 52: 739–747, 1982). As the error would be mainly due to CO2 exchange and be proportional to its partial pressure (PCO2), we studied in nine normal subjects the influence of increasing alveolar PCO2 from 30 to 50 Torr on TGV measurements at panting frequencies (f) of 0.5 and 22.5 Hz. Contrary to model predictions, CO2 tended to decrease TGV estimates at low frequency and to increase them at high frequency. As a consequence, frequency dependence of TGV (delta TGV/delta f) was less at high than at low PCO2 (-39 +/- 32 vs. -84 +/- 49 ml x Hz-1, P less than 0.001). The data are not satisfactorily explained but suggest that gas exchange is not an important factor in TGV measurements.

In a group of 34 inpatients showing varying degrees of airflow obstruction we studied the relationship between breath sound intensity (BSI) and abnormalities of lung function. The BSI was evaluated by chest auscultation to provide a score, in a manner similar to that described by Pardee et al. (1976), and was found to correlate closely with indices of airflow obstruction of their logarithms such as specific conductance (r = 0.759), maximal expiratory flow at 50% of vital capacity (r = 0.790), forced expiratory volume in one second (r = 0.768), and forced expiratory volume to vital capacity ratio (r = 0.860). Correlations with lung volumes, although statistically significant, were weaker. Multiple correlation studies showed that BSI score correlated independently with indices of both airflow obstruction and lung distension. In our experience, BSI score can be useful not only in the detection but also the quantification of airflow obstruction, although its predictive power is impaired in subjects with associated restrictive disorders. It can also fail to detect mild, pure airflow obstruction.

The validity of several roentgenographic indices in predicting lung overinflation was assessed by three independent observers in 25 patients with chronic obstructive lung disease. The observers were unaware of the clinical status of the patients or the purpose of the study. There were significant correlations between the observers for several indices whereas the only good correlation between the indices and radiologic total lung capacity (percent predicted) was the level of the diaphragmatic domes.

We indirectly determined the transmission path of sound generated by sternal percussion in five healthy subjects. We percussed the sternum of each subject while recording the output audio signal at the posterior left and right upper and lower lung zones. Sound measurements were done during apnea at functional residual capacity, total lung capacity, and residual volume both with the lungs filled with air and with an 80% He-20% O2 (heliox) gas mixture. Three acoustic indexes were calculated from the output sound pulse: the peak-to-peak amplitude, the peak frequency, and the mid-power frequency. We found that the average values of all indexes tended to be greater in the upper than in the ipsilateral lower lung zones. In the upper zones, peak-to-peak amplitude was greater at total lung capacity and residual volume than at functional residual capacity. Replacing air with heliox did not change these results. These experiments, together with others performed during Mueller and Valsalva maneuvers, suggest that resonance of the chest cage is the predominant factor determining the transmission of sternal percussion sounds to the posterior chest wall. The transmission seems to be only minimally affected by the acoustic characteristics of the lung parenchyma.

The variability and reproducibility of maximal static respiratory pressure measurements was evaluated in 22 healthy subjects and 17 patients with chronic respiratory disease. The difference between consecutive measurements represented 4 to 8 per cent of the result in healthy subjects and 10 to 11 per cent in patients. The difference between the first and the second measurement was not significant and the two values were highly correlated. At 1 to 3 days interval, the results may differ by 10 to 15 per cent in healthy subjects and 20 to 22 per cent in patients. These differences tend to be greater for expiratory (as compared to inspiratory) pressures and for females (as compared to males). A preliminary assessment of the variability and reproducibility of maximal respiratory pressures is compulsory for a valid interpretation of their change in clinical studies.

A group of 6 males with severe alpha1-antitrypsin deficiency, underwent clinical and pulmonary function evaluation. Findings were compared to those in a group of males with different degrees of airflow obstruction, comparable ages and tobacco consumption, but with normal serum levels of alpha1-antitrypsin. The deficient group was characterized by: (1) a relatively early appearance of symptoms; (2) disturbed lung scans, mostly in the basal zones; (3) radiological evidence, in most cases, of pulmonary emphysema with, in particular, bullae in the lower lung zones; (4) hypoxemia without hypercapnia and a decreased TCO/VA, and (5) a more or less severe reduction of maximal expiratory flows largely, but not exclusively due to a decrease in lung elastic recoil. Clinical and functional parameters did not permit a clear distinction between the deficient and non-deficient groups.

To assess their value for early recognition of airway abnormalities, forced expiration slope ratios as recently defined by Mead, were measured at 5 lung volumes in 114 healthy nonsmokers and in 76 cigarette smokers. In healthy nonsmokers, slope ratios were independent of sex and body height, but were significantly correlated with age. They tended to be higher at low lung volume, particularly in older subjects. In male smokers with a tobacco consumption of less than 5 pack-years, slope ratios were increased at both ends of the volume range, suggesting nonhomogeneous lung emptying and peripheral airway obstruction. With increasing tobacco consumption, slope ratios tended to return to normal values at low lung volume, perhaps because of airway closure. In female smokers, slope ratios were decreased at high lung volume and increased at low lung volume, suggesting that both central and peripheral airways were abnormal. Mead's analysis appeared to be a useful tool for discussing the data in terms of functional abnormalities. However, because of their large variability, slope ratios were not as successful as transit time indices for recognizing abnormal subjects.

In an attempt to identify patterns of variation in airflow obstruction and to detect patients with marked bronchial lability, a factor reported to be associated with an increased risk of sudden asthma death, we obtained serial peak expiratory flow rate (PEFR) recordings from out-patients with chronic, clinically stable, asthma (N = 27) for one week. Similar recordings were obtained for comparison from out-patients with chronic obstructive pulmonary disease (COPD) (N = 14) and from healthy controls (N = 14). Analysis of the recordings disclosed patterns of PEFR variation for 20 asthmatics but not for COPD patients or healthy subjects. Ten asthmatics were classified as "brittle" asthmatics (BA), nine as morning dippers (MD) and one as a gradually deteriorating (GD) asthmatic. Patients were considered at risk when their diurnal fall (DF) in PEFR was greater than 50% on at least one occasion during the survey. This was the case for seven BA, three MD and one GD patient. Diurnal falls in PEFR of this magnitude were not observed among asthmatics without a discernible pattern of variation of airflow obstruction or COPD patients. A relationship was found between the amplitude of PEFR fluctuations and the frequency of significant DF in PEFR (greater than 25%) during half or more days of the survey. A significant fraction of out-patients with chronic, clinically stable asthma may present patterns of variation in airflow obstruction and diurnal falls in PEFR of a magnitude such as has been associated with sudden asthma death.

Auscultatory percussion of the chest is a clinical examination method that has been purported to detect intrapulmonary masses by their effect on transmission of the percussion note to the posterior chest. Recent findings from this laboratory suggested that the sound of sternal percussion may actually travel through the chest cage and not the lung parenchyma. To investigate this possibility further, we recorded the sound produced by sternal percussion at 63 evenly spaced points over the posterior chest wall of 3 healthy subjects and 4 patients with large, discrete intrathoracic lesions in the right upper lobe (2 patients), left lower lobe, and left upper lobe (1 patient each). We constructed 3-dimensional contour maps of the indices of sound amplitude and frequency to view graphically the pattern of distribution of the sound. Examination of the maps revealed areas of increased amplitude in the zones of projection of some osseous structures, especially the scapulae, both in the healthy subjects and patients. No disturbances in the pattern reflecting the presence of mediastinal structures or intrathoracic lesions were found despite the existence of deeply situated lung masses as large as 10 cm in diameter. These findings support the argument that the sound of sternal percussion travels to the posterior chest predominantly through chest wall structures.

Using an integrated flow pressure-corrected body plethysmograph we obtained total lung capacities (TLC) derived from thoracic gas volumes measured at low, medium, and high panting frequencies in 10 healthy men and in 13 patients with chronic airflow obstruction before and after an aerosol of albuterol. Using a gastric balloon we also assessed gastric-to-mouth pressure ratios (delta Pga/delta Pm). In patients before albuterol, estimated TLC remained unchanged from low to medium and increased (not significantly) from medium to high frequency. Healthy subjects and patients after albuterol showed a significant decrease in TLC from low to medium panting frequencies, which persisted after correcting the data for abdominal gas compression using observed delta Pga/delta Pm. In patients after albuterol the results may be explained, at least in part, by intrathoracic airway compliance and mechanical inhomogeneity of the lung. In healthy subjects a remote possibility is the association of mechanical inhomogeneity and nonuniform pleural pressure.

Summary. The purpose of this experiment was to test the hypothesis that airway closure impedes the production of lung sounds at low lung volume. We recorded breath sounds in three healthy men during inspiratory vital capacity manoeuvres in upright, head-down and lateral decubitus postures. We then compared the rate of increase of breath sound intensity (BSI) between the dependent and non-dependent lung zones. Closing volumes, measured separately, were normal in the upright but increased in the head-down postures. The data revealed no consistent lag in the rate of increase of BSI over the dependent lung zones in any of the postures. Our data suggest that airway closure does not influence lung sound generation. If true, this implies that lung sounds are produced proximally to the site of physiologic airway closure.

The clinical usefulness of lung compliance calculated indirectly was reassessed in a large number of healthy subjects and patients with chronic airflow obstruction or restrictive lung disorders. Indirect compliance was calculated from maximal expiratory flow-volume (MEFV) curve and airway resistance measured plethysmographically according to two approaches. In the first (approach A) all calculations were done at the functional residual capacity, whereas in the second (approach B) they were obtained over the 50-75% volume range of the forced vital capacity; values were compared to those of direct compliance measured concurrently. For the group as a whole, the correlations between indirect and direct values were poor regardless of the approach. Examined separately, the best correlations were found for the healthy group using approach A (r = 0.501) and for the obstructive group using approach B (r = 0.312). Failure to derive a valuable indirect compliance is due to the fact that there is a very poor correlation between upstream resistance and airway resistance measured by body plethysmography.U

We report two cases of patients with Von Recklinghausen disease. They exhibited typical cutaneous and diffuse intrapulmonary lesions accompanied by effort dyspnea. Multiple radiological abnormalities were noticed and the pictures showed nodular and interstitial lesions as well as emphysematous areas. Pulmonary function tests revealed more or less marked hypoxemia without hypercapnia, and decreased maximal expiratory flows due, at least in part, to a loss of elastic recoil.

Static lung volumes were measured plethysmographically one hour apart in healthy subjects (n = 14) and in patients with chronic pulmonary disorders of various etiologies (n = 25). The total lung capacity (TLC) obtained from paired measurements of functional residual capacity (FRC) and inspiratory capacity (IC) was calculated according to the four following methods: 1) average FRC plus the largest IC, 2) average FRC plus the average IC, 3) largest sum of FRC and corresponding IC, and 4) average of individual FRC and IC sums. The data, analysed for average values and for reproducibility in the group as a whole and in the healthy subjects and patients separately indicate that: a) For the group as a whole the largest average TLC values were found with method 3 followed by methods 4 and 1. The differences were statistically significant for all comparisons but one (method 1 vs method 4). A similar pattern was found for the healthy subjects and patients separately. b) For the group as a whole, the one hour reproducibility tended to be worse from method 1 through method 4 but the intermethod differences were not statistically significant. For the healthy subjects, the reproducibility tended to be better for methods 3 and 4 and for the patients this was the case for methods 1 and 2. The average reproducibiltiy of methods 1 and 2 was similar for both the healthy and patient groups and these methods seemed more suitable for TLC calculations. Because it is more widely employed, method 1 is recommended.

A group of ten elderly subjects who were apparently normal from the cardiac and pulmonary points of view, were selected on criteria of history, clinical findings, radiological and E.C.G. findings, with a view to a study of respiratory function based on two aspects: alveolar exchanges were assessed by measurement of the ductance of carbon monoxide and the elastic properties of the lung together with bronchial permeability. Although alveolar exchanges are little modified, one may note some pulmonary distension, especially in the smokers, together with a reduction in elasticity. The changes in bronchial permeability which affect the peripheral and central airways, are mainly found in smokers. One may determine the respective roles of extrinsic and intrinsic bronchial obstruction in these abnormalities. One may thus consider that, from the pulmonary point of view, the elderly patient faced with a surgical operation should be considered a high risk for respiratory decompensation, especially if he is, or has been, a smoker.