Pulmonary function studies before and after jejunoileal bypass surgery

Nine out of twelve obese patients (75%) demonstrated diminished minute ventilation volume (MVV) prior to jejunoileal bypass surgery. Seven out of the nine patients (78%) showed improvement in the MVV as weight reduction ensued following surgery. Other parameters, including arterial blood gases, did not change after weight loss. Weight reduction as a result of jejunoileal bypass surgery brings about an improvement in pulmonary function.

Asthma and wheezy bronchitis in children. Skin test reactivity in cases, their parents and siblings. A controlled population study of sex differences

Twice as many boys as girls are prone to wheeze (15-3% compared with 7%). This study examines the possible immunological basis for this phenomenon. There were 1064 children in this survey. The family of each wheezy child was indexed, and a control sample of families was selected. At least 85% of the study population were skin tested for Type 1 allergic reactions. An interval survey of values for FEV1, FVC and PEFR against height was completed. Of 118 wheezy subjects there were 83/542 boys and 35/522 girls. Single and multiple sensitivity, the capacity to react to two or more major allergens, is examined. Of the child asthmatics, significant differences from controls emerge for pollens, foods and the house dust mite. These differences are borne out with multiple sensitivity. (P greater than 0-001.) Of the brothers and sisters of asthmatics, only the sisters show differences from controls. This is true for grass pollen, cow's milk and the house dust mite, and also to a highly significant degree for multiple sensitivity (P greater than 0-001). When the incidence of multiple sensitivity is expressed for all children in the asthma group, that is, cases and their siblings, the sex difference is not demonstrable. The mothers (P greater than 0-05) and fathers (P greater than 0-01), of asthmatics also differ from control parents in respect of skin sensitivity. If multiple sensitivity is equated with atopy, it may not be the main determination of the capacity to wheeze, and thus of the sex difference. The mean curve for interval PEFR for asthmatic children was significantly lower than that of control children and of the brothers and sisters of asthmatics.

Carbuterol, fenoterol, orciprenaline, salbutamol and terbutaline per os in reversible obstructive chronic bronchitis

The effects of tablets of carbuterol, orciprenaline, salbutemol, terbutaline and fenoterol at two dosages were studied using FEV1 and specific airway conductance as parameters. A placebo was used as a reference. Carbuterol and fenoterol proved to be more potent than the other sympathomimetic competitors. Fenoterol 5 mg was on the average somewhat less potent than 3 mg carbuterol. This differnce was not statistically significant for FEV1; it was significant three hours after intake for airway conductance. None of the drugs produced significant changes of the blood pressure. Carbuterol and 12 mg fenoterol caused a statistically significant increase in heart rate. ECG changes were observed in eight patients with the different beta-sympathomimetics, with the exception of 5 mg fenoterol.

The forced expiratory time as a measure of small airway resistance

1. In five subjects, ten consecutive forced expiratory spirograms were recorded on each of 6 different days and the total forced expiratory time (FET) on each spirogram was measured. The mean overall coefficient of variation of the FET was 11.3% and of the ratio forced vital capacity (FVC)/FET was 8%. 2. Twenty-two subjects with probable small (less than 2 mm diameter) airway dysfunction as manifested by a reduced (less than 75% predicted) maximum mid-expiratory flow (MMEF) in the middle 50% of the FVC with normal FVC and FEV1 (greater than 80% predicted) were studied before and after bronchodilatation. There was no significant correlation between change in FET and change in MMEF (r = 0.36, P greater than 0.01), but between change in MMEF (deltaMMEF) and change in FVC/FET (deltaFVC/FET) there was a positive correlation (r = 0.78, P less than 0.001). 3. In six of these twenty-two subjects, the deltaFVC/FET and deltaMMEF on bronchodilatation correlated well with the change in residual volume (deltaRV). but neither measurement correlated well with the change in the 'closing volume' measurement expressed as the ratio of phase 4/VC(%). The deltaFET did not correlate well with either deltaRV or delta[phase 4/VC(%)]. 4. In eighty-one selected normal subjects (FVC, FEV1 and MMEF all greater than 80% predicted) there was better correlation of age with the FVC/FET (r = -0.676) than with the FET (r = +0.43); both correlations were significant (P less than 0.001). 5. These results do not support the use of the FET as a suitable test of small airway function; however, the mean flow rate expressed as FVC/FET may, in the presence of a normal FEV1/FVC ratio, be an adequate test of small airway function.

Inhibitory effects of various drugs on dual asthmatic responses in wheat flour-sensitive subjects

In order to investigate the mechanism of late asthmatic response (LAR), inhibitory effects of various drugs for LAR were examined in two wheat flour-sensitive asthmatic subjects who showed immediate and late responses in the allergen provocation test and skin test. Antihistamines did not inhibit the LAR but totally or partially inhibited the immediate response. By contrast, corticosteroids inhibited the LAR but not the immediate response. Disodium cromoglycate inhibited both responses. Diethyl carbamazine citrate, an inhibitor of release of SRS-A, seemed to shorten the duration of the LAR, although it has no effect on the immediate response and/or on the severity of the LAR. Indomethacin and acetyl salicylate, which inhibit prostaglandin synthesis, had no significant effects on either the immediate or the LAR.

[Air pollution due to cigarette smoke: physiological and irritating effects]

We assessed the effects on the judgement of air quality, eye blinking rate,and lung functions of air pollution due to cigarette smoke. At the same time, subjective irritations were recorded. The measured effects were brought into relationship with the concentration of some pollutants in the air.

Studies of respiratory morbidity in rubber workers. Part IV. Respiratory morbidity in talc workers

Pulmonary function tests, chest x-rays, and respiratory questionnaires were administered to eighty talc workers and 189 non-exposed rubber workers from three rubber tire manufacturing plants. The talc workers, who were exposed to talc at levels below the current threshold limit value (TLV) of 20 mppcf for nonfibrous talc, had a statistically significantly greater prevalence of productive cough and of positive criteria for chronic obstructive lung disease (COLD) than did the control workers. The talc workers with more than 10 years of exposure had significantly decreased residual FEV 1.0. Multiple regression analysis of FEV 1.0 in the talc workers estimated that each year of exposure to talc dust reduced the FEV 1.0 by 26 ml. Talc workers had a clear increase in respiratory morbidity, despite the absence of chest roentgenographic changes. Based on this study, a safe exposure level for talc appears to be 25 mg/m3 as a time-weighted average.

Spirometric comparison of carbuterol and isoproterenol aerosol therapy in bronchial asthma. A double blind, matched-pair study of 28 adults and a double blind crossover study of 18 children

Two adrenergic aerosols were compared in a double blind, matched-pair study of 6 months' duration in 28 adult patients with chronic bronchial asthma, and in a double blind, crossover, short-term study in 18 children with severe asthma. In the adult study, one member of each pair was given either 150 mug of isoproterenol or 200 mug of carbuterol 4 times per day, by inhalation, for 6 months. In the childhood study, 18 children, 6 to 12 years of age, with moderate to severe asthma were studied in a double blind, crossover therapeutic trial in which high or low doses of aerosolized carbuterol or isoproterenol were given 4 times daily for 5 days each. Treatment results were evaluated by measuring forced vital capacity, 1-sec forced expiratory volume, and maximal mid-expiratory flow (FEF25-75%) at regulat intervals before and after administration of the respective test drugs. In the adult study, there was a significant difference between carbuterol and isoproterenol for forced vital capacity (P less than 0.02), for 1-sec forced expiratory volume (P less than 0.02), and for FEF25-75% (P less than 0.01) in favor of carbuterol. In the pediatric study, the difference between carbuterol and isoproterenol was significant (P less than 0.05) only for the FEF25-75% on the fifth day of treatment with the high dose administration of carbuterol. There was no associated toxicity of either drug with respect to electrocardiogram, blood chemistry, or subjective complaints. Tachyphylaxis (tolerance with time) to isoproterenol appeared to develop in one patient.

Cardiopulmonary effects of long-term bronchodilator administration

Because of reports of drug tolerance occurring with chronic use of adrenergic agents in asthma, we investigated cardiopulmonary responsiveness to ephedrine and to the beta-2 agent, tebutaline, following chronic drug administration for periods up to one year. With chronic drug administration baseline (prior to daily medication) FEV increased 19% in the terbutaline group and 3.5% in the ephedrine group. An additional increase of FEV above baseline of 23% for terbutaline and 12% for ephedrine was noted after daily medication. Terbutaline also had a longer duration of effect; peak response after ephedrine occurred at 2 hr while terbutaline effect was maximal at 3 to 4 hr. There was no evidence for reduced responsiveness to the bronchodilator actions of either drug at any time. Despite prolonged use, both drugs continue to increase heart rate and pulse pressure moderately following ingestion, with a peak effect occurring at 3 hr; however, pulse pressure widened after terbutaline because of a diastolic fall, while the major effect of ephedrine was to increase systolic pressure. Baseline blood pressure, particularly diastolic, declined progressively with continued drug use. No evidence of cardiac, ehpatic, renal, or ophthalmologic toxicity or change in need for other bronchodilator agents was noted during the study with either drug.

Inhibition of exercise-induced bronchospasm by atropine

The ability of atropine to inhibit exercise-induced bronchospasm was evaluated in 18 children with chronic, perennial asthma. In 17 of 18 patients, exercise-induced bronchospasm was blocked by prior inhalation of 0.1 mg per kg of atropine sulfate, administered in a randomized single blind fashion. In 14 of these 17 patients, significant bronchodilatation occured after the combination of atropine and exercise. Placebo failed to inhibit exercise-induced bronchospasm in any patient. These results suggest that the parasympathetic nervous system has a role in the mediation of exercise-induced bronchospasm in children.

The effect of sodium cromoglycate on analgesic-induced asthmatic reactions

The onset of increased airways obstruction after analgesic ingestion by asthmatics with analgesic idiosyncrasy suggests an immediate type 1 allergic response. The effect of sodium cromoglycate (DSCG) on this response was assessed in nineteen patients with this syndrome. DSCG prevented asthmatic attacks in only three patients, all non-atopic, suggesting that analgesic idiosyncrasy is not an allergic disorder, The effectiveness of DSCG in preventing asthmatic attacks in some patients with analgesic idiosyncrasy would suggest that a trial of this preparation should be undertaken before commencing continuous corticosteroid therapy.

Action of isoprenaline on the mechanical properties of lungs and airways in healthy people and patients with obstructive lung diseases

Lung volumes, maximal expiratory flows, pulmonary resistance and static recoil pressure-volume curves were measured before and after inhalation of isoprenaline in four groups of subjects: heqlthy patients with mild and severe chronic bronchitis and asthmatics. The observed changes were qualitatively similar in the four groups. Whereas total lung capacity and dynamic compliance were not influenced, there was an increase in vital capacity (not in healthy subjects and mild bronchitics), in FEV1, in maximal expiratory flows and a decrease in pulmonary resistance. The static recoil pressure-volume relationship was shifted to the left over its ascending part. The effect of isoprenaline tended to be larger in patients. Among the latter, the increase of vital capacity was especially pronounced in the severe bronchitics, whereas the maximal flows increased most in asthmatics. We suggest that the influence of isoprenaline on maximal flows results from a bronchodilation, associated with an increased collapsibility of the central intrathoracic airways, whereas the influence of VC might reflect a delayed onset of small airway closure.

Effect of modification of the smoking habit on lung function

The effect of smoking cessation or modification on lung function was determined during a 48-week period. In a large number of the cigarette smokers, a disturbance of lung function was not revealed by conventional tests, such as the 1-sec forced expiratory volume; however, an abnormality was often demonstrable in tests that may reflect alterations in small airways, such as closing volume and Phase III of the single-breath expired N2 curve. There was no relation between the degree of abnormality of lung function and the presence of respiratory symptoms, but there appeared to be a relationship to lifetime smoking history, the heaviest smokers having the poorest function. Cessation, or more than 25 per cent decrease in the number of cigarettes smoked, was attened by improvement in the slope of Phase III of the N2 washout curve, closing volume, and closing capacity, as well as forced vital capacity, 1-sec forced expiratory volume, and peak flow. Resumption of smoking after cessation was attended by a deterioration in the slope of Phase III and closing capacity. The data suggest that the functional abnormalities in smokers are related to smoking and are at least partially reversible by cessation or significant modification of the smoking habit.

Pulmonary effects of chronic exposure to airborne cadmium

Workers chronically exposed to high concentrations of airborne cadmium showed a significantly decreased forced vital capacity relative to a low-exposure group and had Po2 values in the normal range, but at the extreme low end. They had no significant decrease in 1-sec forced expiratory volume or maximal mid-expiratory flow. Chest roentgenograms showed mild or moderate interstitial fibrosis in 29 per cent of the group exposed to cadmium. Collectively, these results suggest a mild fibrotic reaction associated with exposure to cadmium. A dose-response association was observed between forced vital capacity, expressed as per cent predicted, and both average urinary cadmium concentration (P less than 0.003; r=-0.53) and maximal urinary cadmium concentration (P less than 0.005; r=-0.51). Further, a dose-response relationship was found between the forced vital capacity and months of work in cadmium fume areas, but not for months of exposure to cadmium sulfate aerosol.

Oral terbutaline sulfate--amelioration of exercise-induced bronchospasm

Bronchospasm can be induced in asthmatics when exercised according to a multistage branching treadmill protocol that allows them to achieve 80 per cent of their age-predicted maximal heart rate. This present study was undertaken to investigate the effect of oral terbutaline sulfate in ameliorating exercise-induced bronchospasm. Ten asthmatics were exercised, and FEV1.0 and MMEFR were assessed while standing, using a Jones Pulmonar II waterless spirometer at 5, 15, and 30 minutes after exercise. Three hours before exercise, the subjects received no medication, oral placebo, or 5 mg terbutaline sulfate orally. At all time intervals after exercise, the pulmonary function of the group pretreated with oral terbutaline was superior when compared to the no-medication group (P less than 0.01) and to the placebo-treated group (P less than 0.05). Oral terbutaline appeared to normalize the exercise tolerance of the asthmatics and restore physiologic pulmonary airway conductance by the parameters of FEV1.0 and MMEFR.

[A comparative trial of bronchodilator effects of fenoteral and sch 1000 in chronic bronchitis (author's transl)]

In a group of 20 patients with chronic bronchitis, bronchodilator effects of fenoterol (400 mug), SCH 1000 (40 mug), and their combination (fenoterol 400 mug msch 1000 40 mug) have been evaluated and compared by measuring total pulmonary capacity (CPT), intrthoracic gas volume (VGT), forced expiratory volume in one second (VEMS), specific airways resistance (SRva) and maximun expiratory flow at a lung volume for which the initial flow was 0.1 l/s (Vo.iv). Measurements have been made before and 30, 60, 120 and 180 min after administration of the drug. With each of the three drugs, the improvement of the five functional parameters is statistically significant at all time intervals. Changes in CPT, VGT, VEMS and SRva are not statistically different when using the different drugs, whereas the Vo.1v changes suggest a lesser bronchodilator effect of SCH 1000 than fenoterol (p less than 0.05 at 180 min), and especially than fenoterol-SCH 1000 combination (p less than 0.05 at all time intervals). The combination is lightly but not significantly better than fenoterol only. On account of these results and the very high tolerance for the two drugs, a new medication combining SCH 1000 and fenoterol is desirable. The authors emphasize the sensitivity of maximum expiratory flow measurements at low lung volumes for trials on bronchodilators and the necessity to consider the possible reduction in CPT for flows comparison at an identical absolute lung volume.

[Relation between manifest bronchial obstruction and bronchial hyperreactivity (author's transl)]

Based on the inquiry of 252 patients an investigation was carried out concerning the frequency of manifest bronchial obstruction in dependence on the bronchial hyperreactivity. Patients with bronchial hyperreactivity showed more frequently with a high significance as well a decrease in the FEV1 as an increase of resistance. Therefore in dependence on the occurrence of a manifest bronchial obstruction also the probability of a simultaneous presence of bronchial hyperreactivity increases. The results are important for understanding the functional dynamics of the bronchopulmonary system, especially the evocation of dyspnea by irritation of the respiratory tract.

A long-term study of low-dose aerosolized terbutaline sulfate

The purpose of this study was to evaluate the safety and efficacy of a new lowdose terbutaline sulfate aerosol (375 micrograms) over a six-week period. The question of drug tolerance was also evaluated. Twenty-four ambulant patients with chronic obstructive pulmonary disease with a component of reversible airway disease was evaluated. The patients were tested at two-week intervals during a six-week period. The patients abstained from all bronchodilatory medications for at least 10 hours prior to the time of evaluation. The evaluation consisted of baseline FEV1 and MMEFR determinations, ECG, CBC, urinalysis, and renal and liver function tests. After the terbutaline was administered, a rhythm strip and pulmonary function tests were repeated at 5, 15, 30, 60, 120, and 180 minutes. Throughout the six-week study there was a statistically significant increase in FEV1 and MMEFR, (P less than 0.001). No change was noted in the systolic blood pressures; however, heart rate and diastolic blood pressure decreased significantly. No drug tolerance, paradoxical bronchospasm, subjective side effects, no abnormal laboratory results were noted during the study period.

Diagnosis of obstruction of the upper and central airways

Patients with obstruction of the upper airways are often treated for long periods of time for other disorders. Correct diagnosis is important since treatment is quite specific. Such patients may present with a characteristic history and findings on physical examination. Certain physiologic tests such as flow-volume loops with and without helium help to prove the diagnosis. Patients with upper airway obstruction may also have sleep apneas and the sleep deprivation syndrome. Methods of diagnosis of upper airway obstruction are presented and three instructive cases are reviewed.

WRL 105 strain (H3N2) live attenuated influenza vaccine: acceptability, reactivity, and antibody response in normal, bronchitic, and geriatric volunteers

The acceptability, reactivity, and antibody responses of recombinant WRL 105 strain, live, attenuated influenza virus vaccine administered intranasally were studied in seventeen normal adults, and in seventeen bronchitic and twenty-one geriatric volunteers. The effect on peak flow and 1-second forced expiratory volume (F.E.V.1) on the 3rd, 5th, and 7th days after vaccination was measured in the bronchitic and normal groups. Seroconversion occurred in 80% to tht homologous virus, in 40.6% to A/Victoria/3/75, and in 26.5% to A/England/864/75 in subjects with pre-vaccination haemagglutination inhibition titres of less than 1/40. A fourfold or greater increase in homologous anti-neuraminidase antibody was found in 48% of twenty-seven infected subjects when measured by a new elution inhibition technique. The frequency and nature of symptoms were similar in both infected and non-infected groups. No significant changes in F.E.V.1 occurred, but on days 5 and 7 there was a decrease in peak flow measurements in both infected and non-infected groups when assessed as the percentage change of the pre-vaccination value.

Lung function tests in bronchial asthma during and after pregnancy

Respiratory function tests (forced vital capacity and forced expiratory volume in one second) were performed serially in pregnancy, the puerperium, and at least six weeks post partum in 27 patients with a history of asthma and in 12 control subjects. Eleven asthmatic patients with spirometric evidence of respiratory obstruction in pregnancy on at least one occasion were considered to have active disease. This group had significantly impaired respiratory function tests when compared to controls. The remaining 16 asthmatic patients were considered to be in remission. No changes in respiratory function tests attributable to pregnancy could be demonstrated in the asthma or control groups. Patients with active asthma tended to have smaller babies than patients with asthma in remission or the control patients.

Pulmonary function in survivors of Wilm's tumor. Patterns of impairment

Whole-lung irradiation in Wilms' Tumor patients has been given prophylactically and for treatment of metastasis. Thirty-three children with Wilm's tumor who have survived for 4 to 20 years from the time of diagnosis were avaiable for study. Whole-lung irradiation was given in doses from 1163 to 1370 rads (orthovoltage). Eighteen patients (Group N) received no irradiation to the lungs. The remaining 15 patients were divided according to whether pulmonary irradiation was given for metastatic disease (Group M--10 patients) or for prophylactic treatment (Group P--five patients). All but five patients in Group N received at least one course of actinomycin D. A routine set of pulmonary function tests was done to assess possible abnormalities of lung volume and the mechanics of breathing. Group N was normal. The findings in Group M suggested moderately reduced lung volumes and may have also reflected obstruction of the large airways and/or a limited expiratory effort. Group P had essentially normal lung volumes but also appeared to have obstruction of the larger airways. Abnormalities were generally not severe; only two patients, in Group M, were symptomatic. Excess irradiation, presence of metastatsis, additional lung irradiation, and pneumonitis may have contributed to morbidity.

Breathing mechanics, dead space and gas exchange in the extremely obese, breathing spontaneously and during anaesthesia with intermittent positive pressure ventilation

Breathing mechanics and gas exchange were studied in 10 extremely obese subjects (average weight 138 kg) prior to and during anaesthesia with mechanical ventilation. Breathing mechanics were analysed from measurements of transpulmonary pressure (during anaesthesia, trans-chest wall pressure as well) inspiratory gas flow and tidal volume. Gas exchange was studied by analysing inspired and from the Bohr equation, and the division into anatomical and alveolar dead space was arrived at by capnography. The patients were anaesthetised with neuroltpt agents and ventilated with an air-oxygen mixture. Lung compliance during spontaneous breathing was below normal and decreased further during artificial ventilation. Chest wall compliance measured during anaesthesia was within normal limits. Lung resistance was above normal during spontaneous breathing and increased further during mechanical ventilation. Total dead space was normal during spontaneous breathing and increased moderately during artificial ventilation, the increment coming mainly from alveolar dead space. A moderate hypoxaemia was recorded during spontaneous breathing, and the alveolar-arterial oxygen tension difference was slightly elevated. During anaesthesia this difference was markedly greater. It is concluded that the most probable reason for the relative hypoxaemia is right-to-left shunting.

Long-term use of intermittent positive-pressure breathing (IPPB) in chronic obstructive pulmonary disease

The long-term use of intermittent positive-pressure breathing (IPPB) to deliver bronchodilator was compared to delivery by air compressor in 88 patients with chronic obstructive pulmonary disease who were in the home care program. There was no difference between the two groups in terms of number of hospital admissions, days spent in hospital, or mortality. The deterioration in ventilatory function was the same in both groups, althouth the patients receiving IPPB appeared to have developed greater hyperinflation. The data suggest that there is little evidence to support the long-term use of IPPB in the therapy of most patients with chronic obstructive pulmonary disease.

Small airways in fibrosing alveolitis

Pulmonary function, including lung elastic recoil, was measured in 9 subjects with fibrosing alveolitis. Closing volume and upstream conductance were studied to assess small airway function. Lung volumes, diffusing capacity, and transfer coefficient were decreased. Peak expiratory flow and the ratio of 1-sec forced expiratory volume to forced vital capacity were normal, whereas total lung resistance was low, suggesting that large airways were not narrowed. Lung elastic recoil was increased, but the changes could be accounted for by the loss of lung volume. Closing volume and closing capacity were increased when expressed as a percentage of vital capacity and total lung capacity, respectively; but again, this could be accounted for by the decrease in lung volume, because the absolute lung volume at which airway closure occurred was normal. Upstream conductance was not reduced. We conclude that there is no evidence of narrowing of functional small airways in ventilated parts of the lung. The mechanical findings are compatible with the patchy involvement seen pathologically in fibrosing alveolitis.

A trial of aerosolized theophylline in relieving bronchospasm

Theophylline was administered as an aerosol to nine patients with known bronchospastic disease. No significant improvement in the forced expiratory volume in one second was observed after administration of aerosolized theophylline, although improvement did occur following administration of aerosolized isoproterenol. The theoretic mechanisms of bronchodilator aerosols are discussed, as well as the possible reasons for not obtaining a response with administration of theophylline.

Respiratory disease of workers harvesting grain

The incidence of respiratory symptoms caused by grain dust during harvesting was surveyed in a group of Lincolnshire farmers. A quarter complained of respiratory distress after working on combine harvesters or near grain driers and elevators, with cough, wheezing, and breathlessness, sometimes so severe as to prevent work. The airborne dust around combine harvesters contained up to 200 million fungus spores/m3 air with Cladosporium predominant while drivers were exposed to up to 20 million spores/m3 air. Verticillium/Paecilomyces type spores, mostly from Verticillium lecanii, Aphanocladium album, and Paecilomyces bacillosporus, were abundant in the dust. Extracts of these species produced immediate weal reactions in skin tests, precipitin reactions with sera, and rapid decreases in FEV1 when inhaled by affected workers. There was no delayed reactions. Results suggest type I immediate hypersensitivity to the spores although the physical effect of a heavy dust deposit could be important. Drivers could be protected by cabs ventilated with filtered air.

Use of H2 as an inert gas during diving: pulmonary function during H2-O2 breathing at 7.06 ATA

A review of the characteristics of hydrogen as an inert gas for use in diving is presented, with special emphasis on the extension of the respiratory limitation in diving by use of this least dense of all gases. Forced vital capacity, FEV1, FEV2, PEFR, PIFR, and MVV were measured on groups of subjects using the following gas mixtures, all at 7.06 ATA: four subjects breathing 97% H2-3% O2, two subjects breathing 97% He-3% O2, and two subjects using 97% N2-3% O2. The MVV while breathing H2-O2 at 7.06 ATA was 14% higher than with air at the surface, and was improved 40% compared with He-O2 and 171% when compared with N2-O2 at 7.06 ATA. Similar findings were obtained for FEV1, FEV2, PEFR, and PIFR. The values in this study for the relationship of relative gas density (rho) to flow are rho-0.41 for MVV, rho-0.44 for PEFR, and rho-0.45 for PIFR (method of Wood and Bryan).

The effect of oral doxantrazole on allergen-induced bronchospasm

The protective effect of 200 mg doxantrazole given orally on allergen-induced bronchoconstriction has been compared with 20 mg inhaled disodium cromoglycate (DSCG) in 15 patients with bronchial asthma and immediate-type hypersensitivity. Only four out of the 15 patients showed a significant inhibition of their bronchoconstriction after the oral intake of doxantrazole. Nine patients were significantly protected by 20 mg DSCG. All patients responding to doxantrazole also responded well to DSCG.

Metabolic changes in exercise-induced and methacholine-induced bronchoconstriction

Metabolic and physiological responses to graded exercise and methacholine challenge were investigated in asthmatics with or without exercise-induced bronchoconstriction. The results showed that after methacholine challenge, free fatty acid levels increased only in patients with exercise-induced asthma, while they increased in both groups of asthmatics after treadmill exercise. No significant changes were noted in plasma lactic acid levels, ventilation, or oxygen consumption among the groups studied. These data suggest that asthmatics with exercise-induced bronchoconstriction may differ from other asthmatics in some of their metabolic responses.

The ventilatory response to carbon dioxide in asthmatic children, measured by the mouth-occlusion method (Pm100)

Ventilatory responses to carbon dioxide vary widely in patients with bronchial asthma; some have a high response despite increased airway resistance. This paradoxical response was studied in 31 asthmatic children and 22 age-matched healthy children. Measurement of the ventilatory response to carbon dioxide with a conventional rebreathing method showed wide variation in the patients, paralleling the degree of their airway obstruction as measured by the one-second forced expiratory volume and maximal midexpiratory flow rate, but their mean response was similar to that in the control subjects. The ventilatory response was then determined with a new index (Pm100), which rises linearly with increasing carbon dioxide concentration. Despite wide variation in the slope of Pm100 in the patients, their mean response significantly exceeded normal, confirming that the neurochemical drive is increased in bronchial asthma.

Respiratory response to tobacco dust exposure

Results of a study of the respiratory responses of 318 nonsmoking female workers to long-term tobacco dust exposure are reported. The mean total tobacco dust concentrations ranged from 0.9 to 27.5 mg per m3; the respirable fraction, from 0.3 to 3.6 mg per m3. The mean length of exposure to tobacco dust was 14.9 years; 24 per cent of the workers had been exposed to tobacco dust for 20 years or more. Comparatively low prevalences of chronic respiratory symptoms were found, and only the prevalences of chest tightness and wheezing were significantly higher among workers exposed to tobacco dust than those of the control group (P less than 0.01). Calculating the expected 1-sec forced expiratory volume and forced vital capacity values by means of multiple linear regression equations, developed on the basis of data obtained in the 210 control subjects, revealed no significant differences between the measured and expected ventilatory capacity values among any of the groups of the workers observed. In contrast to negative findings with regard to chronic respiratory effects, significant acute decreases in ventilatory capacity during the work shift were recorded. No dose-response relationship was found between the level of exposure and the acute decreases in ventilatory capacity.

Bronchial reactions to aerosol inhalant vehicle

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Refractory period to aspirin in a patient with aspirin-induced asthma

Oral aspirin challenge was used to detect unrecognized aspirin intolerance in a select group of 50 asthmatic patients who denied aspirin intolerance. A double-blind protocol was used to further study those patients who reacted to initial graded aspirin challenge. In one patient the use of a double-blind protocol led to the serendipitous discovery of a 72-hr refractory period to the adverse effects of aspirin, after initial ingestion of aspirin resulted in respiratory and systemic symptoms.

Respiratory function, cardiovascular dimensions and work capacity in boys with bronchial asthma

Twenty boys with bronchial asthma, aged 8-13 years, were studied with regard to the size of their respiratory and circulatory organs and to their excercise tolerance. The boys were divided into two groups (A and B) depending on the severity of their subjective symptoms. Normal values were found for TLC, VC, and FRC in both groups, whereas the group with the most severe asthma had a slightly increased RV. In both groups THb, blood and heart volumes were normal. A quite normal relationship between these variables was observed as well as with work capacity (W170 and VO2 max) with no intergroup differences. Respiratory rate was lower and ventilation was increased in group B, both in submaximal and maximal exercise. Thus, tidal volume in maximal exercise exceeded 50 per cent of vital capacity in this group. These boys also had the highest blood lactate concentration at submaximal and maximal exercise. In half of the boys asthma-like attacks were elicited by the excercise. The symptoms subsided without treatment shortly after work. The frequency and intensity of attacks were similar in the two groups.

Early detection of airway abnormalities in a selected group of population

Functional data were collected from 5,746 males from a country region, whose ages ranged from 14 to 65 years. Out of this population we excluded a group of 466 males (9%) who had abnormal results of traditional pulmonary function screening tests (FVC less than 80% reference values or FEV1% FVC less than 70%) and chose a group of 1,092 males (19%) with normal values for the above two parameters but with abnormal forced mid-expiratory flow. In randomly selected persons of the second group we found frequency dependent dynamic compliance (100%), abnormal maximum expiratory flow at 25% of vital capacity (98%), increased residual volume (76%), decreased maximum expiratory flow at 50% of vital capacity (67%), and increased closing capacity (57%); on the contrary static complicane and airway resistance were normal. To account for these results we suppose that measurement of forced mid-expiratory flow, abnormal values of which we obtained in practically one fifth of the experimental population, could represent, in agreement with other reports, a suitable screening test for first or early detection of airway abnormalities.

Accidental exposure to isocyanate fumes in a group of firemen

A total of 35 firemen involved in fighting a fire in a factory in which polyurethane foam was made were exposed to fumes of toluene di-isocyanate from two large storage tanks which were damaged during the fire, resulting in massive spillage. Most of the men experienced symptoms during the fire or during the three weeks after it. The symptoms were mainly gastrointestinal, respiratory, or neurological. Altogether 15 men described gastrointestinal symptoms which subsided within two days of onset. Respiratory symptoms were described by 31 men and were most pronounced during the three days after the fire, thereafter tending to improve. The neurological findings are described separately. When the men were reviewed at six months there was a suggestion that some of them might have sustained long-term damage to the respiratory tract, and almost four years later 20 men had persistent respiratory symptoms. Serial measurements of ventilatory capacity revealed a marked decline in the first six months although this was not sustained.

The maximal expiratory flow-volume curve. Normal standards, variability, and effects of age

From a randomly selected population representative of the white population of Tucson, Ariz., satisfactory flow-volume data were obtained for 3,115 persons. Data from the 746 subjects who were totally free of symptoms or history of cardiorespiratory disease and who had never smoked were used in determining "normal" prediction equations for spirometric parameters and maximal expiratory flows. The maximal expiratory flow-volume curve showed considerable intersubject variability, but little change in shape of the mean maximal expiratory flow-volume curve was seen with advancing age when the effects of disease, insult, or injury were excluded.

[Differential diagnosis of chronic obstructive lung disease, A statistical analysis of the discriminating power of various lung function tests (author's transl)]

Among 65 patients admitted to the hospital for chronic obstructive lung disease, the following pulmonary tests were systematically performed : spirometric vital capacity and total lung capacity, FEV1, functional residual capacity and total lung capacity measured by body plethysmography, airway resistance and specific conductance, CO diffusion capacity measured by single-breath test, N2 clearance by single breath oxygen dilution, and blood gases. The patients were divided into bronchitics, emphysematous and broncho-emphysematous, according to the clinical and radiological Nash's score, and to another personal score derived from the former. The simple and multiple correlations between the clinico-radiological score and the functional results are low. The clustering analysis groups the 65 patients into four clouds of points, around two principal axes : the volume axis and the overinflation axis. This study indicates that the most suggestive results for emphysema diagnosis are increased FRC and TLC and low Tlco/V'a. The clinical score is not dominant for the clustering of the patients into the dynamic clouds. Beneath the bronchitic, the broncho-emphysematous and the emphysematous groups, the clustering analysis individualizes a fourth group of cases characterized by chronic asthma, and which were not isolated by Nash's score.

Perception of asthma

Subjective assessment and objective measurements of airways obstruction were compared in 82 patients during methacholine-induced asthma. 15% of the patients were unable to sense the presence of marked airways obstruction (forced expired volume in 1 s less than 50% of the predicted normal value). These subjects could not be characterised as a distinct group on the basis of their sex, age, or duration of their asthma. This reinforces the need for objective measurement of lung function in the management of asthma.

Airflometer: new toy or worthwhile advance?

The Airflometer provides a useful index of expiratory flow rate and as such it is a worthwhile advance. It can provide an accurate index of FEV1 provided it is individually calibrated. Perhaps the only limitation is the lack of response of the instrument at low flow rates, for example, with an FEV1 of less than one litre. It is remarkably inexpensive.

Bronchial reactivity to histamine before and after sodium cromoglycate in bronchial asthma

Out of 19 patients with extrinsic bronchial asthma challenged with 123 mug histamine acid phosphate by intravenous infusion only 13 responded with a fall in FEV1 of over 10% (mean 16%). Seventeen of these patients were given histamine 2 mg/ml by aerosol, and all responded with a mean decrease in FEV1 of 37.8%. When challenged with allergen extract by aerosol the mean decrease in FEV1 was 37.5%. After 40 mg sodium cromoglycate 15 of the 17 patients showed significant protection against allergen challenge with a mean decrease in FEV1 of only 23.6%. Inhalation of 40 mg sodium cromoglycate, however, failed to protect against histamine given by either the intravenous or aerosol route. Histamine given intravenously to asthmatic patients produces less of a bronchial response than when given by aerosol, even though the intravenous route produces many more systemic symptoms, such as flushing and throbbing headache. The protection of sodium cromoglycate against an allergen inhalation challenge is not due to histamine antagonsim.

Twelve-minute walking test for assessing disability in chronic bronchitis

The distance covered in 12 minutes' walking was used to test exercise tolerance in chronic bronchitis. The distance covered bore a poor relation to the forced expiratory volume in 1 second but a significant relation to the forced vital capacity and the maximum oxygen consumption and ventilation on a bicycle ergometer. The test may be a simple practical guide to everyday disability in chronic bronchitis.