The respiratory effects of cobalt.

We studied seven subjects with certain manifestations of cobalt-induced lung disease. All worked with cobalt and were involved in either the production or use of hard metal. The mode of presentation varied from an acute hypersensitivity pneumonitis that cleared completely when exposure ceased to progressive severe interstitial fibrosis of the lungs. In one subject reexposure was followed by a recurrence of the symptoms. All subjects showed restrictive ventilatory impairment and a reduction of their diffusing capacity. The radiologic appearances varied greatly. While two subjects had clear roentgenograms with small lung volumes, others had a micronodular pattern or small blotchy nodular infiltrates, and one had diffuse reticulonodulation as is seen in cryptogenic fibrosing alveolitis. The pathologic appearances varied between desquamative interstitial pneumonia and overt mural fibrosis of the alveoli. Six of the seven patients had multinucleated giant cells in their biopsy specimens or bronchoalveolar lavage fluid.

Clinical pharmacology and toxicology of ipratropium bromide.

Anticholinergic drugs inhibit a variety of intrapulmonary events related to airflow obstruction. When administered as an inhaled aerosol, approximately 90 percent of ipratropium bromide (as with beta-adrenergic aerosols) can be assumed to be swallowed. Peak pharmacologic effects occur prior to any detectable plasma drug concentrations. Ipratropium does not exhibit the well-known toxic effects of atropine, and doses many times those required for maximum therapeutic benefit do not produce any effects on the eye, urinary bladder, heart rate, or mucociliary function. Ipratropium seems to act primarily on large- and intermediate-size airways; beta-adrenergic agents, on the other hand, appear to act primarily on the smaller airways. The drug is a promising addition to the therapeutic armamentarium, and may be especially useful in certain groups of patients whose condition is less responsive to other agents.

Comparison of the anticholinergic bronchodilator ipratropium bromide with metaproterenol in chronic obstructive pulmonary disease. A 90-day multi-center study.

The short- and long-term efficacy and safety of an inhaled quaternary ammonium anticholinergic agent, ipratropium bromide, and a beta agonist aerosol, metaproterenol, were compared in 261 nonatopic patients with chronic obstructive pulmonary disease (COPD). The study was a randomized, double-blind, 90-day, parallel-group trial. On three test days-one, 45, and 90-mean peak responses for forced expiratory volume in one second and forced vital capacity and mean area under the time-response curve were higher for ipratropium than for metaproterenol. Clinical improvement was noted in both treatment groups, especially during the first treatment month, with persistence of improvement throughout the remainder of the study. Side effects were relatively infrequent and generally mild; tremor, a complication of beta agonists, was not reported by any subject receiving ipratropium. These results support the effectiveness and safety of long-term treatment with inhaled ipratropium in COPD.

Selection of patients with hemoptysis for fiberoptic bronchoscopy.

One hundred ten hospitalized patients with hemoptysis were reviewed to identify factors that would characterize those with malignancy and to evaluate the usefulness of fiberoptic bronchoscopy (FB) in the diagnosis of hemoptysis. Seventy patients underwent FB. This procedure was diagnostic in 22/28 (79 percent) of the carcinoma patients and in 26/42 (62 percent) of the patients with a nonmalignant cause of hemoptysis. The following three characteristics indicate a high probability of malignancy: 1) age greater than 40 years, 2) any abnormality on the chest roentgenogram, 3) hemoptysis lasting greater than one week. If any of these factors are present, FB should be done. Other factors to be considered include presence of anemia, weight loss, persistent cough, long smoking history and risk of bronchoscopic complications.

Variability of the volume of isoflow.

Twenty healthy hospital workers produced maximal expiratory flow-volume curves before and after three vital capacity inhalations of an 80 percent helium and 20 percent oxygen mixture (HE+O2) in the morning and afternoon for four days during one week. Ten healthy trade union apprentices underwent the same tests, twice on one day and again one month later. Measurements made from curves (and their mean coefficients of variation) were: VisoV (105 percent) FVC (3 percent), FEF50% (6 percent), FEF75% (8 percent), the ratio of FEF50% breathing He+O2 to FEF50% breathing air (6 percent), and the ratio of FEF75% breathing He+O2 to FEF75% breathing air (9 percent). Differences among separate observers contributed significantly to the high variability of the VisoV. Diurnal changes and training effects over the week of study were not significant. In conclusion, VisoV is poorly reproducible compared with the FVC and expiratory flow rates at low lung volumes breathing air and He+O2. This should be considered when interpreting results in a given individual.

COPD in the elderly. A reversible cause of functional impairment.

OBJECTIVES: To determine the frequency of referral of patients age 69 years and older to the pulmonary function laboratory at a tertiary-care hospital for airflow limitation studies; to determine the point prevalence of a significant reversible component in patients with COPD as an age-related function; and to determine the proportion of patients who were prescribed bronchodilators following a pulmonary function test (PFT) demonstrating significant reversibility. DESIGN: A retrospective review of pulmonary function tests of patients 69 years and older within calendar year 1990 was performed. Chart review of those showing significant reversibility to bronchodilators during a PFT was performed to determine level of follow-up. SETTING: Referral-based pulmonary division in a tertiary-care hospital. PATIENTS: Men and women 69 years and older who had interpretable PFTs at Northwestern Memorial Hospital (NMH) during the calendar year 1990 (n = 405). Patients whose PFTs were uninterpretable due to poor effort (n = 10) were excluded from the study. INTERVENTIONS: No specific interventions were performed as a part of the study. Referring physicians may have requested a PFT with postbronchodilator (albuterol by nebulizer) testing and may have subsequently prescribed bronchodilators for their patients. MEASUREMENTS: We studied the effect of age, gender, smoking history, and degree of airflow obstruction on changes in spirometry values and reversibility status after bronchodilator (if applicable) as determined by a PFT. MAIN RESULTS: Of the 405 consecutive elderly patients studied, 193 (47.7%) received bronchodilators and 60 (31.1%) of these patients had significant improvement as judged by the criteria listed in the Methods section. The improvement occurred equally across all age groups (p > 0.05) and the percent responding to bronchodilators increased as the degree of obstruction increased (p < 0.001). Those who had never smoked were twice as likely to respond than were current or former smokers; men were more likely to respond than women. Most patients (84%) who responded were subsequently prescribed bronchodilators. CONCLUSIONS: Responses to inhaled bronchodilators occur at all ages. Older patients showed greater reversibility as the degree of obstruction increased, while a smoking history reduced the likelihood of a bronchodilator response. COPD in the elderly may differ from the traditional form of the disease.

The radiologic significance of the left pulmonary ligament. Experience with 26 patients.

Pathologic processes confined to or by the left pulmonary ligament present a confusing radiographic appearance. Such processes may simulate pleural scarring, parenchymal scarring, or even left lower lobe collapse. Radiologic awareness of this structure is limited because in the normal state, it is not visualized on either posteroanterior or lateral chest x-ray films. The absence of secondary signs of left lower lobe collapse, together with a process which may extend above the level of the left hilum, is valuable in confirming that such a triangular density seen behind the left cardiac border is disease in or confined by the pulmonary ligament, rather than left lower lobe collapse.

Airflow effects on amplitude and spectral content of normal breath sounds.

Even though it is well known that breath-sound amplitude (BSA) increases with airflow, the exact quantitative relationships and their distribution within the relevant frequency range have not yet been determined. To evaluate these relationships, the spectral content of tracheal and chest wall breath sounds was measured during breath hold, inspiration, and expiration in six normal men. Average spectra were measured at six flow rates from 0.5 to 3.0 l/s. The areas under the spectral curves of the breath sounds minus the corresponding areas under the breath-hold spectra (BSA) were found to have power relationships with flow (F), best modeled as BSA = k.F alpha, where k and alpha are constants. The overall mean +/- SD value of the power (alpha) was 1.66 +/- 0.35, significantly less than the previously reported second power. Isoflow inspiratory chest wall sound amplitudes were 1.99 +/- 0.70- to 2.43 +/- 0.65-fold larger than the amplitudes of the corresponding expiratory sounds, whereas tracheal sound amplitudes were not dependent on respiratory phase. Isoflow breath sounds from the left posterior base were 32% louder than those from the right lung base (P < 0.01). BSA-F relationships were not frequency dependent during expiration but were significantly stronger in higher than in lower frequencies during inspiration over both posterior bases. These data are compatible with sound generation by turbulent flow in a bifurcating network with 1) flow separation, 2) downstream movement of eddies, and 3) collision of fast-moving cores of the inflowing air with carinas, all occurring during inspiration but not during expiration.

Flutter in flow-limited collapsible tubes: a mechanism for generation of wheezes.

We studied flutter in collapsible tubes as a possible mechanism for the generation of respiratory wheezes. The pressure-flow relationships and the wall oscillations of thick-walled [wall thickness (h)-to-lumen radius (r) ratio 1:1.7 to 1.3] self-supporting latex and Silastic tubes mounted between rigid pipes were measured. A high-impedance vacuum pump was connected to the downstream end. Upstream and downstream valves were used to control corresponding resistances. We found loud honking sounds and tube wall oscillations that occurred only when the tubes were buckled and flow limiting, i.e., when the flow became constant and independent of downstream driving pressure. The overall range of oscillatory frequencies was 260-750 Hz for airflow, presenting as sharp peaks of power on the frequency spectrum. The oscillatory frequencies (f) were higher at higher fluid velocities (u) and with narrower distance between opposing flattened walls (2b), resulting from increasing downstream suction pressure and the transmural pressure becoming more negative. The effect of u and b on f for a latex tube (h-to-r ratio 1:1.7) were found to be f = 228 + 0.021 (u/b). These relationships were valid throughout the range of oscillations in this tube (283-720 Hz) and with flow rates of 12-64 l/min. The experimental data were compared with predictions of the fluid dynamic flutter theory and the vortex-induced wall vibrations mechanism. We conclude that viscid flutter in soft tubes is the more probable mechanism for the generation of oscillations in the soft tube model and is a possible mechanism for the generation of respiratory wheezes.

The hard metal diseases.

Hard metal is a mixture of tungsten carbide and cobalt, to which small amounts of other metals may be added. It is widely used for industrial purposes whenever extreme hardness and high temperature resistance are needed, such as for cutting tools, oil well drilling bits, and jet engine exhaust ports. Cobalt is the component of hard metal that can be a health hazard. Respiratory diseases occur in workers exposed to cobalt--either in the production of hard metal, from machining hard metal parts, or from other sources. Adverse pulmonary reactions include asthma, hypersensitivity pneumonitis, and interstitial fibrosis. A peculiar, almost unique form of lung fibrosis, giant cell interstitial pneumonia, is closely linked with cobalt exposure.

Surgical management of emphysema.

The history of surgery for the treatment of emphysema and its complications is long and complex and, with improved understanding of the pathophysiology, most procedures have been discarded. Present clear indications for surgery are mainly large or increasing bullae that result in compression of apparently good lung tissue, and complications of bullous emphysema such as pneumothorax and infection. With localized giant bullae the results of local resection can be as dramatic as the effects of pleural drainage for tension pneumothorax. Lobectomy should not be undertaken until bullae have been removed locally and application of positive pressure has failed to reveal any expandable lung tissue--a rare situation. Resection of small bullae generally has no effect on lung function. The indications for resection of large bullae in the presence of diffuse emphysema require careful individual study. In such cases even a small increment of function may be of great clinical benefit, and there is evidence that longevity can be increased. Finally, two-stage local drainage of tension bullae may be indicated in those rare cases in which open thoracotomy cannot be considered for other reasons.

Wideband acoustic transmission of human lungs.

The measurement of sound transmission in human lungs has shown promise to reveal, by noninvasive methods, information about the structure of peripheral airways and lung tissue. The paper gives a detailed explanation of the instrumentation and testing methods developed to measure sound transmission through human lungs and thoracic structures in the 5-20 kHz frequency range and describes in detail experiments comparing the acoustic lung transmission patterns of four different subject groups. The experimental results are compared with those predicted by an acoustical model of sound transmission through lung parenchyma.

[A respiratory health questionnaire for occupational screening].

A Hebrew pulmonary health questionnaire was designed for occupational screening, based on the American Thoracic Society questionnaire but adjusted to conditions in Israel. It was designed for assisted completion using a computer, but can easily be modified to become self-administered. We propose that it be used here as the standard, occupational, pulmonary health questionnaire and as the basis for a standard, general purpose, respiratory health questionnaire.