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Thirteen patients with chronic laryngeal stenosis were operated upon with total excision of stenotic scar tissue, enlargement of the lumen by sectioning the back and front wall of the larynx, and application of an indwelling Teflon prosthesis for 4 months. The stenosis was in many cases caused by long-standing recurrent paralysis complicated by attempted surgical correction of the stenosis. Following operation, the specific airway conductance increased in all patients (mean +/- SD pre and postoperative values 0.51 +/- 0.30 and 1.12 +/- 0.51 kPa-1.s-1, respectively). The FIV1/FVC ratio was determined in 9 patients and an increase was postoperatively noted in all of them (mean +/- SD pre and postoperative values 43 +/- 17 and 76 +/- 13%, respectively). The physiological findings confirmed the excellent clinical results of the treatment. [ABSTRACT FROM AUTHOR]

A rapid dosimetric method with controlled tidal breathing for histamine challenge was evaluated by assessment of its repeatability, by comparing to a present nondosimetric standard method, and by application to adult patients with recent asthma (n = 31), chronic asthma (n = 33), chronic cough (n = 71) or chronic rhinitis (n = 41) and to healthy controls (n = 31). An automatic inhalation-synchronized dosimetric jet nebulizer with a known lung deposition of the aerosol was used to administer histamine and to control breathing. The non-cumulative doses of histamine diphosphate were 0.025, 0.1, 0.4 and 1.6 mg, administered during 0.4 s following tidal inspiration of 100 ml of air. The test procedure required 1 inhalation of histamine 4 mg/ml and followed by 1, 4 and 16 inhalations of histamine 16 mg/ml from the device, and its duration was about 30 minutes. The intraindividual correlation coefficient of the histamine dose causing a reduction of 15 percent in FEV1 (PD15FEV1) on 2 consecutive days in 14 asthmatic subjects was 0.937; the standard error of the single determination was 13 percent of the mean PD15 FEV1. A PD15FEV1 value below 0.4 mg was found only in asthmatic subjects; in chronic asthma, below 0.5 mg; in recent asthma, between 0.1 mg and 1.6 mg or more. In patients with chronic cough and chronic rhinitis, 20 and 32 percent, respectively, the PD15FEV1 values between 0.4 and 1.6 mg, the other patients in these groups were non-responsive. In all healthy control subjects, the PD15FEV1 was over 1.0 mg, 80 percent of them were nonresponsive to the maximum 1.6 mg dose. This new test allows rapid, accurate, and quantitative assessment of bronchial responsiveness to histamine.

The bronchodilator effect of a combination of 200 micrograms salbutamol and 200 micrograms oxitropium bromide, given as pressurized aerosols, was compared to that of 200 and 400 micrograms of salbutamol in a controlled experiment on adult patients with asthma. The combined and the high dose salbutamol treatments were equally effective with respect to the response measured 60 minutes after administration, and both were significantly superior to the low dose salbutamol treatment. Bronchodilation persisted longer following the combined treatment than following the low or high dose salbutamol treatment. The results suggest that enhancement of the early bronchodilator response obtained by adding oxitropium bromide to a conventional dose of salbutamol in patients with stable asthma reflects suboptimal dosing of salbutamol rather than differences between the agents in mechanisms of action, whereas enhancement in duration of response is related also to the pharmacological characteristics of oxitropium bromide.

The acute effect of electric transcutaneous nerve stimulation (TNS) on bronchomotor tone was studied in 20 asthmatics. The stimulation was applied to four classical acupuncture points on the chest and back, and bronchomotor response was determined by measuring peak expiratory flow (PEF). The experiments consisted of an adaptation period, placebo "stimulation", TNS, and an isoprenaline inhalation test, in that order. In 11 patients PEF increased significantly (greater than 15%) after placebo "stimulation"; the mean change in all 20 patients after that period was + 12% (P less than 0.01). TNS, however, did not change PEF significantly in any patient in spite of the fact that marked residual bronchoconstriction was shown in all patients demonstrated by an increase in PEF after inhalation of two isoprenaline puffs at the end of the experiment. The results suggest that the acute bronchodilatation obtainable with TNS is probably psychogenic; no cutaneous-bronchial reflex could be demonstrated. The same kind of psychogenic reaction may also be involved in the bronchodilator response to needle acupuncture in asthma.

Static lung compliance and airway resistance were measured in 30 experiments on 6 healthy subjects after intravenous injection of a bolus of histamine (4 mug per kg of body weight). Analysis of the pooled results showed a significant decrease in static lung compliance (maximal mean decrease,--16 per cent occurring 20 sec after injection). There was no significant change in functional residual capacity or vital capacity after injection of the histamine. Administration of propranolol (a beta-adrenergic blocking agent) did not significantly enhance the responses to histamine. The results suggested that humans, like other species, can constrict peripheral airways sufficiently to produce alterations in the static elastic properties of the lungs.

A case of idiopathic bronchiolitis obliterans in a 40-year-old man is presented. The chest radiograph showed miliary nodules, which on histological examination were found to consist of granulation tissue in and around bronchioles causing narrowing or obliteration of the airway lumen. The pulmonary function tests indicated a milk degree of airway obstruction, ventilation/perfusion inequality, hypoxemia which increased during exercise, and a well-preserved diffusion capacity suggesting absence of significant damage to the interstitium of the lung. Radiospirometry suggested that the functional derangement was most prominent in the lower parts of the lungs. Even though the inflammatory component was prominent no improvement was observed during steroid therapy. A history of respiratory symptoms for 20 years and a slight deterioration of the respiratory function over a follow-up period of 4 years suggested an unusually slow rate of progression of the disease.

To evaluate the preventive effect of inhaled ipratropium powder on low-grade bronchoconstriction elicited by breathing cold air during exercise, we subjected 10 adult patients with mild asthma to four identical treadmill exercise tests. The temperature of inhaled air during exercise was -9 +/- 1 degree C. Sixty minutes before exercise, the patients inhaled either placebo or 0.2, 1, or 2 mg of ipratropium powder according to a cross-over, double-blind arrangement. The mean post-exercise fall from the post-treatment pre-exercise values in the four treatment groups was 14, 14, 16 and 16% for FEV1, and 59, 52, 52 and 55% for SGaw, respectively. We concluded that doses of ipratropium up to 20-50 times higher than those known to have a marked effect on resting bronchomotor tone in clinically stable asthma did not blunt the bronchoconstriction response following exercise with cold air breathing in our patients with mild asthma.

The effect of cromolyn sodium (CS) pressurized aerosol on bronchial hyperreactivity was assessed by comparison with placebo in a double-blind crossover study of 14 adult patients with clinically stable asthma. The trial was performed in a cold climate during the pollen-free winter months and the patient's risk of exposure to clinically relevant allergens was judged to be low. The dose was two puffs, each of 1 mg CS or placebo, four times daily over two successive 4-week periods, the order of treatment being decided by random allocation. No significant difference between treatments was observed in bronchial reactivity to histamine, determined as PC15. There was no difference between treatments with regard to symptoms, which were slight, or daily peak expiratory flow recordings, which showed minimal circadian variation. The results suggest that, although prolonged treatment with CS may decrease bronchial reactivity by reducing airway inflammation secondary to the assault of allergic stimuli, the drug probably has little or no effect on the basal bronchial reactivity in asthma.

A simple device for measuring ventilatory function, the airflowmeter, was found to be at least as sensitive as the Wright peak-flow meter in detecting histamine-induced bronchoconstriction in asthmatic patients. The apparatus also was found suitable for monitoring ventilatory function by the patients themselves at home.

The difference in CO2 tension between arterial blood and end-tidal alveolar gas (a-end-tidal)DCO2 was found to correlate fairly well with the VD/VT ratio in 13 healthy subjects and 50 patients with pulmonary diseases (r = 0.74), and to discriminate between healthy subjects and patient groups at least as effectively as did the VD/VT ratio. An increase in breathing frequency from 8 to 32/min, without simultaneous change in alveolar ventilation, was associated with a mean increase in (a-end-tidal) DCO2 of several mmHg in both the healthy subjects and the patient groups. It is concluded that measurement of (a-end-tidal)DCO2 seems to be a clinically useful alternative to measurement of VD/VT ratio for evaluation of the wasted ventilation component, provided that the effect of the breathing frequency on (a-end-tidal) DCO2 is taken into account.

Attention is drawn to the fact, obvious for simple mathematical reasons, that in patients that airway obstruction the values for specific airway conductance (SGaw) calculated directly from the flow-pressure loop registered during quiet breathing with a constant-volume body plethysmography closely approximate the values obtained by the conventional plethysmographic method which includes temporary interruption of the airflow. The simplified procedure may be useful e.g. in serial determinations of SGaw in situations where simultaneous measurement of the lung volume is not considered essential.