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Interstitial lung disease developed in a 32-yr-old chemist after working 8 yr in a dusty atmosphere containing aluminum powders. Bronchoalveolar lavage disclosed a helper T-lymphocyte alveolitis, and transbronchial lung biopsies showed sarcoidlike epithelioid granulomas. These granulomas contained dust identified by mineralogic analyses as consisting mainly of aluminum particles. Nasal and liver biopsies and a Kveim test did not reveal extrapulmonary granulomatous infiltration. An extensive immunologic work-up showed none of the abnormalities classically seen in sarcoidosis, but peripheral blood lymphocytes exhibited blastic transformation in the presence of soluble aluminum compounds. About 1 yr after cessation of exposure, a chest radiograph and lung function tests remained essentially unchanged, but signs of alveolitis disappeared. This observation suggests that aluminum may cause granulomatous lung disease accompanied by a helper T-lymphocyte alveolitis, similar to that of berylliosis and sarcoidosis. Further observations would be necessary to show if this constitutes an early stage of aluminum-induced fibrosis (aluminum lung).

To determine the action of the parasternal intercostals on the human rib cage, we studied the pattern of rib cage motion in relation to the pattern of respiratory muscle contraction in 4 normal subjects during attempts to perform tidal volume breathing with the parasternal intercostals alone. The dimensions of the chest wall, including the anteroposterior (AP) diameters of the lower rib cage and the abdomen, the transverse diameter of the lower rib cage, and the xiphipubic distance, were measured with linearized magnetometers. The electromyogram (EMG) of the diaphragm was obtained with an esophageal lead, while the EMGs of the intercostal, neck, and abdominal muscles were recorded using concentric needle electrodes. Minimizing diaphragmatic use during inspiration (transdiaphragmatic pressure = 0.08 to 1.54 cm H2O) was accompanied by a recruitment of the parasternals that was substantially greater than that of the scalenes; in 2 of the subjects, the activation of the scalenes at the beginning of inspiration was even delayed relative to the parasternals. The lateral intercostals showed variable changes during the maneuver, but the sternocleidomastoids, pectoralis major, rectus abdominis, and abdominal external oblique muscles were always silent. This pattern of EMG activity was associated with profound deformations of the rib cage. In all 4 subjects, the rib cage expanded considerably more along its transverse than its AP dimension relative to its relaxed configuration, and in 3 subjects, the xiphi-pubic distance decreased rather than increased in early inspiration.(ABSTRACT TRUNCATED AT 250 WORDS)

Eighteen sequential follow-up measurements of pulmonary function were obtained over a period of 21 months after heart-lung transplantation in a patient who had undergone surgery for end-stage pulmonary lymphangioleiomyomatosis. In the early postoperative period, there was a moderate decrease in VC and TLC but gas exchange was maintained at essentially normal levels. The most conspicuous features of postoperative lung function were a very low airway resistance and an increase in FEV1/VC ratio above 95%. These alterations were associated with an unusual shape of the maximal expiratory flow-volume (MEFV) curve. Instead of showing a uniform decrease in expiratory flow as expiration proceeds to residual volume, the post-transplant MEFV curve showed a peak followed by a gently sloping plateau ending at a knee where flow suddenly fell. The knee occurred after exhalation of 80% VC. From the sixth postoperative month, the patient developed rapidly increasing air-flow obstruction, which proved to be due to obliterative bronchiolitis. As air-flow obstruction worsened, the knee on the MEFV curve progressively occurred at a higher lung volume, the flow plateau shortened, and flow after the knee became smaller at a given volume. From the ninth postoperative month, it was no longer possible to identify a plateau-knee configuration on the MEFV curve, which resembled that seen in severe obstructive airway disease.(ABSTRACT TRUNCATED AT 250 WORDS)

The variability of quasistatic lung inspiratory and expiratory pressure-volume (P-V) curves has been investigated in 8 young healthy volunteers studied on 4 occasions. The reproducibility of the total lung capacity (TLC) measured by body plethysmography was good, with a mean coefficient of variation of 1.8 +/- 0.9% (SD). The following variables were calculated from the P-V curves: the recoil pressures measured at TLC and 90, 80, 70, 60, and 50% TLC, as well as the compliance at functional residual capacity. For all the variables considered the intraseries variance was similar to the interseries variance so that all the individual results were pooled together. For each variable a coefficient of variation was calculated for each subject, as well as an F ratio to compare the interindividual differences to the intraindividual differences. For the variables obtained from the expiratory P-V curve, the lowest coefficient of variation was found for elastic lung recoil pressure, 90% TLC (6.6 +/- 2.6%, mean +/- SD). The reproducibility of the inspiratory P-V curve was found to be somewhat better than that of the expiratory one, with a coefficient of variation of 3.4 +/- 0.8% at 90% TLC. In absolute terms at that same level, the mean standard error of measurements was 1.2 cm H2O for the expiratory curves and 0.8 cm H2O for the inspiratory ones. It is concluded that in terms of reproducibility the best index of lung elasticity is the recoil pressure measured at 90% TLC and that the inspiratory curve is even better than the expiratory one.

A patient with myotonia congenita (Thomsen's disease) presented with unpleasant sensations of tightness in the chest and dyspnea, which were maximal at the beginning of exercise and gradually improved as exercise progressed. Lung function tests and maximal static respiratory pressures were within normal limits. Precise electromyographic (EMG) and mechanical studies, however, demonstrated the increased excitability, impaired relaxation, and transient weakness of the respiratory muscles. These studies thus indicate that myotonia congenita may involve the respiratory muscles to the same extent as any other skeletal muscle, and that precise EMG studies are occasionally useful in determining the organic basis of respiratory symptoms.

We studied the effects of an intravenous injection of 5.0 mg of aminophylline per kg of body weight on lung mechanics in 8 normal subjects. No change occurred in lung volumes, airway resistance, and maximal expiratory flow-volume and lung pressure-volume curves. Restudy of 4 of the subjects before and after an injection of 8.0 mg/kg of aminophylline did not modify the pattern of response to the drug, despite a serum concentration range of 15.1 to 19.3 mg/l. These findings were, therefore, in contrast with those observed after the administration of atropine or beta-2 adrenergic derivatives. They suggested that the bronchodilator effects of aminophylline may not be due to a direct action of the drug on the bronchial smooth muscle.

It is well established that unlike normal subjects patients with cervical cord transection have an increase in VC when changing from the seated to the supine posture. To investigate the mechanism of this paradoxical increase, we measured static lung volumes in both the seated and supine posture in 14 consecutive patients with tetraplegia (C4-C7) and in 4 patients with paraplegia (Th4-Th7). The increase in VC in the supine compared with the seated posture was (mean +/- SE) 0.41 +/- 0.07 L (16.0% of the seated value) in the tetraplegic subjects and 0.40 +/- 0.01 L (11.2% of the seated value) in the paraplegic subjects (p less than 0.001). However, TLC in all subjects was 0.28 +/- 0.05 L smaller in the supine posture (p less than 0.001), thus indicating that the larger VC in this posture is related to a reduction in residual volume (RV) rather than to an increased mechanical advantage of the diaphragm. The reduction in RV in the supine posture was consistent, averaging 0.72 +/- 0.06 L (29.1% of the seated value) in the tetraplegic subjects and 0.62 +/- 0.21 L (37.6 percent of the seated value) in the paraplegic subjects (p less than 0.001). Inflating blood pressure cuffs at the bases of the legs prior to the assumption of the supine posture diminished the reduction in RV with recumbency by only 0.10 +/- 0.02 L. In contrast, the postural dependence of RV was abolished when the abdomen was tightly supported by elastic straps and maintained constant in configuration during postural changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Using the weighted spirometer technique we studied chest wall compliance (Cw) in 16 nonobese patients with chronic weakness of the respiratory muscles and 20 healthy control subjects. In order to evaluate the validity of the technique, while Cw was being measured, we monitored thoracoabdominal configuration with 2 pairs of linearized magnetometers and electrical activity of the external oblique with a concentric needle electrode in 3 healthy subjects and 4 patients; in addition, we recorded in 3 subjects the electrical activity from the intercostal muscles and diaphragm throughout the procedure. The method was reproducible within 5.8% and provided Cw values that compared well with those yielded by the relaxation technique. In each subject, the weight-induced shifts in end-expiratory lung volume showed a very good linear correlation with the changes in transrespiratory pressure at end-expiration (r greater than or equal to 0.91). In addition, in none of the subjects tested did the electromyograms reveal any intercostal, diaphragmatic, or abdominal muscle activity at end-expiration, nor did the end-expiratory level ever show a significant departure from the relaxed thoracoabdominal configuration, thus suggesting adequate respiratory muscle relaxation. The reduction in inspiratory muscle force in the patients ranged from 17 to 94% of predicted (mean +/- SE, 43 +/- 6). The decrease in vital capacity, total lung capacity, and functional residual capacity averaged 59, 34, and 15% of predicted, respectively. Both the patient and the control groups showed a large interindividual variability regarding Cw. It varied from 0.117 to 0.258 L/cm H2O (mean +/- SE, 0.162 +/- 0.012) in the patients and from 0.163 to 0.366 L/cm H2O (mean +/- SE, 0.248 +/- 0.013) in the healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

The static elastic properties of the chest wall have been studied in 20 seated patients in the late stages of traumatic tetraplegia. Chest wall compliance (Cw) was measured using the weighted spirometer technique, and the slope of the relaxation line of the thoracoabdominal system obtained with 2 pairs of linearized magnetometers was used to derive rib cage (Crc) and diaphragm-abdomen (Cab) compliance. The values were compared with those obtained in 61 healthy adults studied with the same procedure. Chest wall compliance and Crc values in the patients were reduced to 72 and 55% of control values (p less than 0.001), respectively, and 9 of 20 patients had Crc values at least 2 SEE below normal. By contrast, Cab values in all patients were increased to 170% of control values (p less than 0.001), and 7 patients had values more than 2 SEE above normal. These alterations were not related to the duration of the disease or to the presence or absence of spastic activity in the parasternal intercostals. Both the decreased rib cage compliance and increased abdominal compliance may contribute to reducing rib cage contribution to tidal volume in tetraplegic subjects. As a corollary, the pattern of rib cage motion in such subjects can only approximately define the isolated action of the diaphragm on the normal human rib cage.

In an attempt to understand the intersubject variation in rib cage motion in tetraplegia, and to assess the isolated action of the diaphragm on the human rib cage, we studied the pattern of rib cage motion in relation to the pattern of nondiaphragmatic respiratory muscle electromyogram (EMG) in 20 tetraplegic patients breathing at rest in the seated posture. The general pattern included a greater expansion of the lower than of the upper rib cage, and a greater and earlier expansion of the lower rib cage in its transverse than in its anteroposterior (AP) diameter. However, whereas the upper rib cage moved paradoxically inward with inspiration in 11 patients, it did not move or slightly expanded in 9 patients; in 1 of these, all rib cage diameters increased in the same proportion during inspiration as during relaxation. This intersubject variation was not related to the duration of tetraplegia, the pattern of the abdominal muscle EMG, or the presence of continuous spastic EMG activity in the parasternal intercostals. By contrast, it was related in part to the pattern of scalene EMG activity: upper rib cage AP paradox was present in 7 of 8 patients with spastic or silent scalenes but only in 4 of 12 patients with phasic inspiratory scalene EMG activity. When studied during quiet breathing in the supine posture, the 8 subjects with denervated scalene, intercostal, and abdominal muscles still showed inspiratory increase in the rib cage transverse diameter, but in 7 patients the lower rib cage AP diameter decreased in concert with the upper rib cage AP diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

In an attempt to assess the action of the sternocleidomastoid muscles on the human rib cage, we studied the pattern of rib cage motion in 2 patients with complete transection of the upper cervical cord. Measurements of rib cage motion were obtained with magnetometers and chest roentgenograms, and concentric needle electrodes were used to record the electromyograms (EMG) of various respiratory muscles. Spontaneous quiet breathing elicited a large amount of phasic inspiratory EMG activity not only in the sternocleidomastoids, but also in the trapezii, platysma, mylohyoid, and sternohyoid muscles. This pattern of muscle use was associated with substantial rib cage deformation. During spontaneous inspiration both patients showed a clear-cut decrease in lower rib cage transverse diameter, and they both had a cranial displacement of the sternum and an increase in upper rib cage anteroposterior diameter that was disproportionately larger than the increase in lower rib cage anteroposterior diameter. Radiographic measurements confirmed these deformations but also demonstrated that the upper rib cage transverse diameter increased rather than decreased with inspiration. These results indicate that: (1) Patients with high tetraplegia use many neck muscles in addition to the sternocleidomastoids to breathe; (2) The synchronous contraction of these muscles acts to pull the sternum cranially, expands the upper rib cage, and causes paradoxical inward displacement of the lateral walls of the lower rib cage; (3) As in dogs, the motion of the upper rib cage in humans is more tightly linked to the sternum than that of the lower rib cage.(ABSTRACT TRUNCATED AT 250 WORDS)