The Spirostat: comparison with water-sealed spirometer

Performance of four Spirostat units in measuring forced expiratory volume, 1 sec (FEV1) and forced vital capacity (FVC) were examined against that of a Collins spirometer using 10 volunteers. One Spirostat was discarded because of gross inaccuracy. The other three were evaluated for accuracy, repeatability and comparability among Spirostats. For FEV1 it reads high over the low ranges and low over the upper ranges. For the FVC, it reads high for all values up to 5.0 liters where it becomes quite accurate. The repeatability was considered only fair, since one spirostat differed from the other two; the comparability was acceptable.

[Obstructive pulmonary emphysema. Evolution of various parameters of pulmonary function and its correlation]

A follow-up study was carried on in a series of 20 patients with chronic obstructive pulmonary disease. The parameters analyzed were forced expiratory volume in the first second (FEV1), maximum voluntary ventilation (MVV), forced expiratory flow (FEF), vital capacity (VC), and diffusing capacity of lung (DL). Considering the importance of the parameter changes observed, each of these parameters were divided in three groups. The period of observation was of two and a half years in 9 patients, and between two years and seven months to four years in 11 patients. The follow-up was characterized by stability of the parameters in cases with the greatest degree of changes, and a definite deterioration of the parameter values in patients with minor degree of basal changes. It was observed an excellent correlation between FEV1 and MVV and FEF. As to CV and DL, the relationship was only good. These findings lead us to believe that MVV and FEF values can be predicted about from the FEV1 results.

Lung function in childhood. III. Measurement of airflow resistance in healthy children

Indices of airflow resistance have been obtained in a group of 248 healthy London schoolchildren from recordings of peak expiratory flow rate (PEFR), forced expiratory volume in 0-75 seconds (FEV 0-75) and maximum mid-expiratory flow (MMEF) and two more direct methods, airways resistance (Raw) measured plethysmographyically and total respiratory resistance (PT) by the forced oscillation technique. The normal data are presented.

Pulmonary diffusing capacity for carbon monoxide in simple coal workers' pneumoconiosis

The lung diffusing capacity for carbon monoxide (DLCO single-breath) and its two components, the capillary blood volume (Vc) and the diffusing capacity of the membrane (DMCO) were measured at rest in 43 miners and 141 control subjects, the values in whom enabled reference formulae to be established; in 30 control subjects and in the majority of the miners these indices were measured during exercise. The main results are as follows: the diffusion indices are on average slightly decreased in simple coal workers' pneumoconiosis; both DMCO and Vc contribute to the lowering of DLCO, at rest and during exercise; individually Vc is more often significantly altered than DMCO; on effort the percentage increase of DLCO is normal in coal miners; the data during exercise suggest that smoking habit contributes more to lowering DLCO than does pneumoconiosis itself; lastly the diffusion indices are lower in miners with "pin-head" than those with micronodular opacities: this tendency is more pronounced during exercise. These findings are discussed.

The relative potencies and beta2-selectivities of intravenous rimiterol, salbutamol and isoprenaline in asthmatic patients

The bronchodilating efficacy and the degree of beta2-selectivity of rimiterol, salbutamol and isoprenaline were determined in seven asthmatic patients. Rimiterol, 0.5 (high dose) and 0.05 mug/kg/min (low dose), salbutamol, 0.3 and 0.03 mug/kg/min, isoprenaline, 0.05 and 0.005 mug/kg/min, and placebo were administered by a single intravenous injection over 6 minutes in a double-blind trial. Airway resistance, heart rate, blood pressure and skeletal muscle tremor were measured before and at various times for 2 hours after each injection. The high doses of rimiterol (37%), salbutamol (37%) and isoprenaline (32%) produced immediate and effective bronchodilatation. The duration of action of rimiterol and isoprenaline was similar and shorter than that of salbutamol. For these ventilatory responses there were heart rate increases of 32, 20 and 40 beats/min for rimiterol, salbutamol and isoprenaline, respectively. The three drugs produced similar increases in pulse pressure and tremor. Dose-responses were obtained for each drug with all parameters measured and significant differences at various times found. Isoprenaline was approximately 8 and 5 times as potent as rimiterol and salbutamol, respectively, in bronchodilator action, when equimolar doses were compared. Similarly, isoprenaline was approximately 16 and 12 times as potent in increasing the heart rate as rimiterol and salbutamol, respectively. For an equal bronchodilator action, isoprenaline increased the heart rate 2 and 2.5 times more than rimiterol and salbutamol, respectively. Rimiterol is an effective, short-acting bronchodilator, with similar beta2-selectivity to salbutamol, when administered intravenously to asthmatic patients. The relative potencies and degrees of beta2-selectivity of these drugs depend partly on their route of administration.

Goblet cells in the peripheral airways in chronic bronchitis

It was not possible to demonstrate an increase in the proportion of goblet cells in the bronchioles of patients with chronic bronchitis and no emphysema, whereas other lesions, such as mucous gland hyperplasia, airway narrowing, and airway mucus were easily demonstrated in similar cases. Thus, it seems that goblet cell metaplasia is not an important factor in patients who have chronic bronchitis but little evidence of chronic airflow obstruction. Goblet cell metaplasia is an obvious feature of patients with chronic bronchitis and emphysema, especially in those with symptomatic or fatal chronic airflow obstruction, and it may be responsible for producing obstruction in the peripheral airways of these subjects. The role of goblet cell metaplasia in smokers with little airflow obstruction is uncertain from the data presented. No difference was noted in the proportion of goblet cells between bronchitic patients and nonbronchitic smokers who did not have clinical airflow obstruction.

Pulmonary function in miners working in British collieries: epidemiological investigations by the National Coal Board

Epidemiological investigations of ventilatory capacity in men working in British coal mines are reviewed. The results are related to radiological category of pneumoconiosis, respiratory symptoms, cigarette smoking and dust exposure. In summary it was found that dust exposure was associated with a fall in FEV1.0 but that there was no further fall assoicated with the presence of simple pneumoconiosis. Simple pneumoconiosis appeared to be evidence of the amount of previous dust exposure and suggested that this had been sufficient to cause a measurable fall in FEV1.0. The extent of the ventilatory impairment associated with simple pneumoconiosis was less than that due to age alone in most men. Cigarette smoking was found to be an important cause of ventilatory impairment.

Cardio-respiratory function in United States coal workers

Over the past five years the cardio-respiratory function of selected groups of U.S. coal workers has been intensively studied. The subjects studied included approximately 10,000 working miners at mines selected as part of an epidemiological study of the prevalence and progression of coal workers' pneumoconiosis (CWP) as well as selected groups of non-working symptomatic miners. The occupation of coal mining per se is sometimes associated with a mild reduction in ventilatory capacity which is not closely related to radiographic category of simple CWP. Slight abnormalities in gas exchange and lung mechanics appear to be associated with the higher categories of simple CWP which do not appear to affect longevity. Subjects with complicated CWP (massive fibrosis) demonstrate moderate to severe degrees of obstruction, abnormalities of gas exchange and lung mechanics that generally relate to the extent of the massive fibrosis and result in premature disability and death.

Pulmonary function in sandblasters' silicosis

Lung function was examined in 55 patients with sandblasters' silicosis. In this type of silicosis, patients with simple nodular disease had normal function. Restrictive and obstructive impairment was present in patients with large opacities, and was more marked in patients with radiographic evidence of contraction or cavitation. In the last group, striking average annual declines in ventilatory function occurred. Compared to patients with classical silicosis, these patients were younger and had intense, short exposures to free crystalline silica. The pattern of functional abnormalities suggested that restriction of lung volumes is a fundamental abnormality in this form of silicosis.

Intravenous treatment with rimiterol and salbutamol in asthma

The bronchodilating efficacies and beta2-adrenoceptor selectivities of rimiterol (0.2, 0.1, and 0.05 mug kg-minus1 min-minus1) and sal-utamol (0.1, 0.5, and 0.025 mug kg-minus1 min-minus1), intravenously infused for one hour, were determined in five patients with chronic asthma. Each drug infusion produced and maintained a dose-related improvement in forced expiratory volune in one second (FEV1). A further increase in FEV1 was produced by inhalation of the same drug by pressurized aerosol at the end of each infusion, which suggested that no resistance had occurred. Similar dose-related increases in heart rate, pulse pressure, and skeletal muscular tremor were produced by each drug. Peak heart rate increases varied greatly between individuals, ranging from 12 to 30 beats/min with the high doses but always less than 10 beats/min with the low doses of each drug. On rimiterol the heart rate reached equilibrium earlier during the infusions and declined more rapidly after they had stopped, thus providing an accurate means for monitoring dosage. Rimeterol with its short half life-a desirable property for an intravenous drug with respect to safety-may prove to be a valuable bronchodilator in severe asthma when intravenous infusions are indicated.

Response of patients with chronic obstructive lung disease to the regular administration of nebulized isoproterenol. A double-blind crossover study

The effect of the regular use of neublized isoproterenol in 14 patients with symptomatic chronic obstructive lung disease (COLD) was evaluated in a double-blind crossover 16-week study. FEV1, FVC and SGaw were measured before and 45 minutes after bronchodilator therapy every two weeks, while arterial blood gases were measured every eight weeks, before and 45 minutes after bronchodilator therapy. When the patients were considered as a group, there was no significant difference in mean symptom scores or objective pulmonary functions during the drug and placebo periods. Four patients had significantly higher (p less than .05) and two patients significantly lower mean values for at least one of the pulmonary function tests during the isoproterenol period. The patient who is most likely to benefit from isoproterenol on a regular basis appears to have the following characteristics; (1) consistent improvement in pulmonary function tests 45 minutes after use of nebulized bronchodilator; (2) moderate rather than severe COLD; and (3) a relatively normal DLCO.

Factors influencing the measurement of closing volume

The various factors influencing closing volume were studied by performing the single-breath N2 test on 9 healthy nonsmokers. Time of day, day of the week, and preceding volume history had no effect on either closing volume or alveolar plateau. Slow inspiratory flow resulted in larger ratio of closing volume to vital capacity, ratio of closing capacity to total lung capacity, and change in N2 concentration than fast inspiratory flow. Voluntary regulation of the expiratory flow resulted in smaller ratios of closing volume to vital capacity and closing capacity to total lung capacity than when flow was regulated by a resistance. Prolonged breath holding of the inspired O2 led to larger ratio of closing volume to vital capacity and ratio of closing capacity to total lung capacity. To obtain uniform, comparable closing volumes, it is suggested that the subject inspire slowly, control expiratory flow (preferably voluntarily), and not pause between inspiration and expiration.

Evaluation of breath holding in hypercapnia as a simple clinical test of respiratory chemosensitivity

Breath holding was used as the basis of a simple test of respiratory chemosensitivity. Breath holding was begun at selected degrees of hypercapnia produced by CO2 rebreathing. In 16 healthy control subjects there was a linear regression of the log of breath-holding time on the PCO2 at the start of breath holding. Breath-holding time (BHT) and the slope of a log BHT/Pco2 plot were closely correlated with the ventilatory response to CO2. In five cases of the idiopathic hypoventilation syndrome, CO2 retention and reduced ventilatory response to CO2 were accompanied by prolonged breath-holding time and the regression of log BHT on Pco2 was abnormally flat. However, in 17 patients with chronic airways obstruction, breath-holding time was never prolonged and the log BHT/Pco2 relationship was normal, even though 13 had a diminished ventilatory response to CO2 and four had chronic CO2 retention. It is concluded that the BHT/Pco2 relationship provides a useful index of respiratory chemosensitivity which is not influenced by airways obstruction. This may be helpful in the detection of impaired chemosensitivity as a cause of CO2 retention even when the ventilation CO2 response is reduced non-specifically by coexisting airways obstruction.

Horizontal gradient in ventilation distribution due to a localized chest wall abnormality

Horizontal gradients in the distribution of ventilation and of regional vital capacities, as well as a reversed vertical, esophageal pressure gradient, were observed in a patient with a unilateral painful chest wall lesion. The distribution abnormalities disappeared after surgical treatment. These findings suggest that the interdependency between chest wall and lungs, and within the latter, between lobes, is an important factor determining the regional distribution of ventilation and the pleural pressure gradient in man.

Comparison of the bronchial response to running and cycling in asthma using an improved definition of the response to work

The bronchial responses to treadmill running and ergometer cycling have been compared in 13 adults with asthma. The exercises were performed on separate days with an interval ranging from three days to six months. The study was designed to ensure that the time course of oxygen consumption during running was replicated during cycling. The response to exercise was estimated by taking serial measurements of the maximum forced expiratory flow rate and forced expiratory volume in one second before and after work. Indices used to describe the response were (b-a)/b and a/b, where b and a were the average lung function before and the lowest value after exercise respectively. There was no significant difference in the lung function of the subjects before running and cycling nor did the duration of exercise or oxygen consumption differ between the two exercises. Eleven of the 13 patients showed a reduction in ventilatory capacity after both forms of exercise. Differences in the lung function responses to the two forms of standard work were trivial and not statistically significant, amounting to only about 1%. It is suggested that previous reports of larger responses to running than cycling were probably due to higher energy expenditures during running. General problems regarding the description and comparison of the responses to exercise are discussed.

Effects of ozone on pulmonary function in normal subjects. An environmental-chamber study

Twenty healthy adults, 10 smokers and 10 nonsmokers, were exposed to 0.5 ppm of ozone for 6 hours in an environmental chamber. They engaged in two 15-min, medium-exercise stints on a bicycle ergometer during this period. The symptoms most commonly noted with exposure to ozone, dry cough and chest discomfort, were experienced by more nonsmokers than smokers. Subjects who experienced symptoms, in general, were those who developed objective evidence of decreased pulmonary function. Significant changes from control values for the group as a whole with exposure to ozone were observed for the following pulmonary function tests: specific airway conductance, pulmonary resistance, forced vital capacity, and 3-sec forced expiratory volume. No significant change was observed with respect to diffusing capacity for CO, static compliance, or the various tests derived from the N2 elimination rate. In addition, nonsmokers exhibited a significant decrease in dynamic compliance after exposure to ozone. When the smokers were considered as a separate group, no significant decrease in pulmonary function was observed, although some individual smokers showed adverse functional changes.

The correlation between skin tests, bronchial provocation tests and the serum level of IgE specific for common allergens in patients with asthma

Cutaneous and bronchial immediate allergic reactivity and the serum level of IgE specific for each of four common inhalant allergens were determined for 153 asthmatic patients. Positive bronchial reactivity to an extract was not detected in any of the patients with a negative prick test reaction to that extract but did occur in 9% of the patients in whom the serum tests results for IgE specific to that allergen fell within the range regarded as negative. Highly significant correlation coefficients between the degree of bronchial and cutaneous allergic reactivity to the allergen extracts were found and these were slightly but significantly less than the correlation between the serum level of allergen specific IgE and the degree of bronchial allergic reactivity to the allergen extracts. These findings indicate that the results both of prick testing with appropriate extracts and estimation of the serum level of allergen specific IgE can be used to predict not only the presence of detectable bronchial reactivity to inhalant allergens but also the degree of this reactivity. However, for the routine investigation of asthmatic patients measurement of the serum level of allergen specific. IgE would appear to have little advantage over properly performed prick tests.

Spirometric standards from 387 healthy New Zealand children

Vital capacity and forced expiratory volume in 1 s were measured in 387 healthy European and 16 non-European children aged from five to 11 years. These measurements were correlated with height, sitting height, arm span, weight, lean weight and age in various combinations. Suitable linear regression equations are presented from which these lung volumes may be predicted with confidence limits down to approximately +/- 400 ml and +/- 200 ml respectively.

Effect of resistive loading on ventilatory response to hypoxia

Ventilatory responses to hypoxia, with and without an inspiratory resistive load, were measured in eight normal subjects, using a rebreathing technique. During the studies, the end-tidal P-CO2 was kept constant at mixed venous level (Pv-CO2) by drawing expired gas through a variable CO2-absorbing bypass. The initial bag O2 concentration was 24% and rebreathing was continued until the O2 concentration in the bag fell to 6% or the subject's arterial oxygen saturation (Sa-O2), monitored continuously by ear oximetry, fell to 70%. Studies with and without the load were performed in a formally randomized order for each subject. Linear regressions for rise in ventilation against fall in Sa-O2 were calculated. The range of unloaded responses was 0.78-3.59 1/min per 1% fall in Sa-O2 and loaded responses 0.37-1.68 1/min per 1% fall in Sa-O2. In each subject, the slope of the response curve during loading fell by an almost constant fraction of the unloaded response, such that the ratio of loaded to unloaded slope in all subjects ranged from 0.41 to 0.48. However, the extrapolated intercept of the response curve on the Sa-O2 axis did not alter significantly indicating that the P-CO2 did not alter between experiments. These results suggest that the change in ventilatory response to hypoxia during inspiratory resistive loading is related to the mechanical load applied, with the loaded slope being directly proportional to the unloaded one.

Changes in lung mechanics during asthma induced by exercise

Pulmonary and airway mechanics were assessed in seven asthmatic patients in remission, when asthma was induced by exercise and again after spontaneous recovery or bronchodilator treatment. After exercise there was a sustained fall in forced expiratory volume in 1 s (FEV 1.0) in all patients, varying from 30 to 80 percent of the initial value. Total lung capacity (TLC) increased significantly in four of the seven patients. In one of the four patients the increase in TLC was associated with an increase in static transpulmonary pressure at full inflation but in the remaining three patients it was associated with a parallel shift of the pressure-volume curve of the lung without change in its slope. In all patients residual volume increased, regardless of change in TLC; both pressure-volume and maximum expiratory flow-volume curves suggested that widespread airway closure (or virtual closure) occurred at positive transpulmonary pressures when asthma was induced. Loss of lung recoli pressure sometimes contributed to the reduction in maximum expiratory flow but diffuse airway narrowing was probably the dominant abnormality. When air-flow obstruction became more severe the ratio of expiratory to inspiratory time was increased and although expiratory flow limitation was present excessive expiratory pressures were not generated.

Provoking factors in bronchial asthma

Asthmatic patients were identified as having asthma on the basis of lung function studies (76%), objective physical findings of asthma (11%), or a strong history of asthma (13%). Each of the 234 patients so identified was assigned to an asthma subgroup determined by careful clinical assessment of the major provoking factor or factors for his asthmatic episodes; minor provoking factors were also identified. Only 20% of the patients had asthmatic episodes provoked by a single factor. Most asthmatics had at least one major and one or more minor provoking factor(s). Reagin-mediated mechanisms constituted the major provoking factor in 25% of patients and were a minor provoking factor in an additional 20% of the patients. Thus, in only 45% of the patients, were reaginic mechanisms responsible for some part of their asthmatic episodes.

Epidemiology of toluene diisocyanate (TDI)-induced respiratory disease

This paper describes our experience with the respiratory effects of TDI. Five respiratory reactions attributable to TDI are described with supporting evidence. The reactions are sensitization, irritation from overexposure, acute loss of ventilatory capacity, accelerated loss of pulmonary function and induction of a general asthmatic state. Evidence is presented that suggests a safe exposure level.

Intravenous prednisolone in chronic bronchial asthma

A single injection of 40 mg prednisolone phosphate was given to 10 patients with chronic bronchial asthma. Changes in pulmonary function were followed over a 30-hour period. Statistically significant changes occurred in the tests employed one hour after the injection of prednisolone. The maximum change for the group as a whole was seen to occur after eight hours. This time course of response is very similar to that obtained in previous studies on similar groups of patients with oral prednisolone where the peak effect occurred nine hours after the drug had been given. Intravenous hydrocortisone produces a much earlier peak effect, at five hours, when it is administered to chronic asthmatic patients.

[Significance of a negative inhalation test in chronic obstructive lung disease]

To assess the bronchospastic component in patients with chronic obstructive lung disease, measurement of vital capacity and forced expiratory volume (FEV) before and after inhalation of a beta-agonist is a widely used procedure. In a minority of patients this simple inhalation test yields a negative result, suggesting the possibility of unresponsive airways. The purpose of this study was to explore th significance of a negative test result by examining pulmonary mechanics in 17 patients before and after inhalation. The results permit the following conclusions: (1) A significant broncholytic action of a beta-agonist can be determined by measuring vital capacity and FEV. As a rule, a negative test cannot be attributed to the alleged insensitivity of spirometric measurements. For clinicla purposes, the more demanding determination of specific airway conductance is not necessary. (2) A negative inhalation test does not imply a pure emphysema with out peripheral airway disease, any more than it does irreversible bronchiolitis. All it proves is the unimportance of bronchiolospasm at the time of examination. The true role of a spatic component in the course of the disease, and the benefit of regular inhalations, can be assessed on the basis of repeated controls only.

Interaction of ephedrine and theophylline

The effectiveness and safety of individualized theophylline doses administered as such and in combination with ephedrine and hydroxyzine was investigated in 23 children with chronic asthma who received these medications and a placebo for 1 week each, double-blind and in randomized sequence. Theophylline, determined by prior clinical titration in each patient, averaged 7.3 mg/kg per dose administered every 6 hr, with peak serum theophylline concentrations averaging about 16 mug/ml. Asthmatic symptoms were controlled with theophylline. Ephedrine, alone or in combination, was relatively ineffectual in these patients. None of the drugs given alone was associated with significant adverse effects but both ephedrine-theophylline combinations (with and without hydroxyzine) were associated with insomnia, nervousness, and gastrointestinal complaints. Since the combinations were not significantly more effective than theophylline alone, the apparent toxicity of these combinations suggests a contraindication for the routine use of ephedrine with theophylline in the management of chronic asthma.

Intravenous isoproterenol: rationale for bronchial asthma

Intravenous isoproterenol was infused into 7 adult asthmatic patients with refractory bronchial obstruction. Over a dose range of 0.0375 to 0.225 mug per kilogram per minute, maximal bronchodilator effect (or reversal of effect) occurred within 2 to 5 minutes of starting (or stopping) the infusion. Obstruction to airflow improved with each increment of dose. Average heart rate reached a maximum at 0.075 mug per kilogram per minute. Over the lower dose range alveolar to arterial oxygen gradients widened and heart rate increased; over the higher dose range, as heart rate plateaued, bronchodilator effect continued and oxygen gradient narrowed. When combined with adequate oxygenation and continual monitoring of cardiac rhythm and blood pressure, intravenous isoproterenol appears safe for asthmatic patients. Major advantages are (1) administration of bronchodilator to airways not reached by inhalation, (2) prompt onset and offset of effects, and (3) reversal of undesirable side effects. The use of intravenous isoproterenol may obviate the need for intubation and ventilatory assist.

Effect of exercise on lung function tests in hay fever

The patients in this study were divided into three groups on the basis of V50. Group I included completely normal subjects with normal V50 before and after exercise. Group II showed a normal initial V50 which decreased following exercise. This indicates small airways dysfunction which is exaggerated by exercise. Group II showed abnormal V50 initially which remained unchanged after exercise, suggesting more permanent impairment of the small airways function. Thus significant physiologic abnormalities were identified in patients belonging to Group II and Group III.

Subsensitivity to epinephrine following the administration of epinephrine and ephedrine to normal individuals

Cardiovascular and metabolic responses to exercise and consecutive epinephrine infusions 24 hours apart were measured in 7 normal individuals before and following a week's administration of ephedrine sulfate. There was evidence of less beta adrenergic response to the second control epinephrine infusion compared to the first control infusion, and the depression of the rise in blood lactate was significantly different. A week of ephedrine produced more profound depression of the beta adrenergic responses to epinephrine with significant differences in the rise in blood glucose and lactate, and the pulse and blood pressure responses. Furthermore, these same responses remained significantly altered when a second epinephrine infusion was performed 36 hours following the last dose of ephedrine. The alterations in the response to epinephrine induced by ephedrine are consistent with the concept of effector cell "subsensitivity," an adaptive response to prolonged excessive stimulation.

Responses to cotton dust

Twelve cotton textile workers were studied: (1) to compare standard measures of volume and expiratory flow, maximal expiratory flow volume (MEFV) curves, closing volume (CV), and closing capacity (CC) in detection of airway narrowing with cotton dust exposure; (2) to evaluate the response of arterial blood gases to exposure; (3) to measure changes in leukocytes in peripheral blood and airway secretions; and (4) to assess the temporal relationships and correlations between measures. Change in expiratory flow (FEV) most consistently and significantly discriminated between the control and cotton dust exposures. Vmax50%FVC was a more sensitive indicator, but variance was increased proportionately. CV and CC changed inconsistently with relatively large variances. The PaO-2 decreased overall and two subjects had large decrements. Peripheral blood and polymorphonuclear cell counts increased with exposure to cotton dust and polymorphonuclear leukocytes were recruited to the nasal mucosa. Chest tightness and decreased flow were temporally correlated with leukocyte recruitment that may be important in respiratory disease among cotton textile workers and therefore deserves further investigation.

Dust exposure in manual flax processing in Egypt

Manual flax processing originated in Egypt in 2 000 BC. In the present study a representative sample of the workers involved in this trade, where flax is processed in small workshops or homes, was examined, and their dust exposure was evaluated. The study showed that workers handling and processing flax are exposed to high concentrations of dust; the levels of dust at hackling and combing are considerably higher than at batting and spinning. Byssinosis prevailed in 22-9% of the examined workers, and 18-4% of them had their forced expiratory volume in one second reduced by more than 10% at the end of the first morning work period (4 hours) of the week. Both the rates and the grades of these syndromes increased with duration of exposure. Smoking appeared to be one of the important contributory factors in the production of byssinosis. The relationship between dust concentration and prevalence of byssinosis seems to be curvilinear.

Pectus excavatum; a clinical study with long term postoperavtive follow-up

There are divergent views about the harm that pectus excavatum and related chest deformities does to the respiratory and heart function. The indications for surgery and the optimal age for surgical intervention are debatable. In this study 37 operated and 38 nonoperated cases of about the same severity have been followed for more than ten years and examined after the age of 18 years. The examination included socio-economic, cosmetic and cardio-pulmonary function aspects. It could be shown that from the psychological aspect there were no significant differences between the operated and the non-operated cases. The tendency to contract bronchopneumonia is not influenced by operation. The physical working capacity was the same in the two groups. The operated cases have slightly lower pulmonary function values that the non-operated in spite of the fact that the non-operated group at the time of follow-up included the more seveee cases. Age at operation did not seem to be of any importance for the long-term results. The lower pulmonary function capacity in the operated cases is thought to be attributed to a restriction secondary to the operation. There are also indications that pectus excavatum tends to become less pronounced with increasing age. The study supports a restrictive attitude towards surgery.

Asynchronous breathing movements in patients with chronic obstructive pulmonary disease

An electromagnetic ventilation monitor was used to record the separate anterior-posterior movements of the chest and abdomen during the breathing cycle in 30 patients with chronic obstructive pulmonary disease (COPD) and in 10 normal subjects. In all normal subjects and 17 COPD patients, the chest and abdomen movements were syndhronous and in phase with the flow of air as measured with a spirometer. In 13 COPD patients chest movement was synchronous with the flow of air, but the abdomen moved inward suddently near or at end inspiration and then outward during a variable part of expiration. Compared to COPD patients with a normal breathing pattern, those with asynchronous breathing movements had poorer ventilatory mechanics and 10 of the 13 were dependent on assisted ventilation. Nine of the 13 patients with asynchronous breathing have died in a 10 month period, a significantly higher mortality than in those with normal breathing.

Treatment of steroid-dependent asthma patients with beclomethasone dipropionate aerosol

Fifty-two steroid-dependent adults with chronic perennial asthma were transferred to beclomethasone dipropionate aerosol. The tests demonstrated a significant improvement with beclomethasone in terms of the diary score, bronchodilator use, and PEF and FEV1.0 measurements, as compared with the previous period of prednisolone treatment. Before the transfer, 26 of the patients displayed one or more diseases or symptoms which were probably due to systemic steroid medication. Morning cortisol levels, along with the response to tetracosactrin had in all cases returned to normal when tests were carried out 41 days after transfer to beclomethasone dipropionate. In a group of 12 patients with the lowest 11-OHCS basal values, the mean of their 11-OHCS values during prednisolone treatment was as low as 0.14 plus or minus 0.06 mumol/l, but tetracosactrin challenge induced an elevation to a normal level, 0.33 plus or minus 0.13 mumol/l. After 41 days of beclomethasone treatment, the corresponding values were 0.56 plus or minus 0.90 plus or minus 0.28 mumol/l. Thirty-seven patients experienced one or more disturbing symptoms after transfer to beclomethasone. In many cases, the symptoms of allergic rhinitis were troublesome and persistent leading to a sixfold increase in the use of antihistaminic tablets. When the patients had learned to exhale through the nose following beclomethasone inhalation, the use of antihistaminic tablets again diminished to some extent. Moreover, two cases of ulcerative colitis were encountered during the beclomethasone treatment. During a follow-up period of one year, 14 patients were again receiving prednisolone; most often, this was due to worsening of the asthma because of respiratory infections. During the beclomethasone treatment, a continuous significant improvement in PEF was noted after isoprenaline inhalation, suggesting that further benefit may be obtained by the employment of bronchodilator aerosols as an essential part of the treatment.

A comparison between measured and calculated changes in the lung function after operation for pulmonary cancer

Eighteen patients operated on for pulmonary cancer, the procedure varying from the removal of two segments to pneumonectomy, were subjected to measurement of the spirometric values VC, FEV1, FRC and RV preoperatively and 2-3 months postoperatively. The possibility of predicting the postoperative values from the number of segments removed was studied, partly with standard percentages (5.26%) per segment (method I), and partly with a percentage per segment in the affected area, calculated from the preoperative regional lung function tests using 133xenon. This latter test was carried out with a mobile apparatus using four detectors with tubular colimators and from the anterior surface of the thorax. Both methods of calculation gave, for the material as a whole, good agreement between the postoperative (measured) and the calculated values. However, with regard to certain patients, the regional lung function tests gave important information on preoperative reduced function in the affected area. In these patients, method No. II was by far the best for prediction of the postoperative values.

Effects of intravenous propranolol and metoprolol and their interaction with isoprenaline on pulmonary function, heart rate and blood pressure in asthmatics

The effects of propranolol (0.06 mg/kg i.v.), the selective beta1-receptor antagonist metoprolol (0.12 mg/kg i.v.) and a placebo on pulmonary function, heart rate and blood pressure have been compared in asthmatics. The interaction of these drugs with increasing doses of isoprenaline on the same variables was also studied. The two beta-blockers reduced resting heart rate to the same extent, indicating the same degree of blockade of cardiac beta-receptors. Both beta-blockers reduced the basal forced expiratory volume in one second (FEV1), and the effect tended to be more pronounced after propranolol. Isoprenaline caused a dose-dependent increase in FEV1 and vital capacity (VC). These effects were almost completely blocked by propranolol, whereas after metoprolol the changes approached that of the placebo. The isoprenaline-induced increase in heart rate and fall in diastolic blood pressure was also inhibited to a considerably greater extent by propranolol than by metoprolol. The results show a selectivity of metoprolol for so-called beta1-receptors and indicate that metoprolol may be used in asthmatics provided that it is combined with beta2-receptor-stimulating drugs.

Pilot study of the effect of terodiline chloride (Bicor) in obstructive pulmonary disease

Terodiline chloride, 150 mg daily, was administered to 10 patients with obstructive pulmonary disease, and pulmonary function tests were performed before and during two weeks of therapy. Serious side effects of anticholinergic type developed in two patients who stopped treatment. Two patients were excluded from the trial for other reasons. The remaining six patients showed signs of bronchodilation. Owing to the high incidence of side effects, treatment with more than 75 mg terodiline chloride per day is impracticable.

Postoperative hypoxaemia and oxygen therapy

Arterial blood and expired gas samples were taken from 20 patients before operation and on the first day after upper abdominal surgery. After operation the patients were studied breathing air and also breathing 35% oxygen from a venturi-type mask. Preoperative Pao2 with age was exaggerated by operation. Pao2 after operation was closely related to, and lower than, the preoperative value. The postoperative Pao2 during oxygen therapy correlated well with the postoperative Pao2 breathing air. Severely hypoxaemic patients show less improvement of oxygen tension during 35% oxygen therapy.

Pulmonary function in asymptomatic adolescents with idiopathic scoliosis

Pulmonary function studies were performed in 28 asymptomatic adolescents with idiopathic scoliosis. Tests included spirometry, flow volume curve, measurements of inspired gas distribution, diffusing capacity, closing volume, ventilatory response to carbon dioxide, and arterial blood gas analysis. In addition to the well-known decreases in lung volumes, a reduction in diffusing capacity, arterial oxygen tension, and ventilatory response to carbon dioxide were also documented. Significant correlations existed between the severity of the spinal curvature and the decrease in lung volumes. A significant correlation was also found between the degree of hypoxemia and the reduction in the diffusing capacity, suggesting that a low diffusing could be the cause of the observed arterial hypoxemia.

Isoproterenol aerosols

Notable acute improvement in pulmonary function in the majority of 32 patients with known bronchial asthma followed two inhalations of Isoproterenol. No deleterious clinical or cardiovascular effects of EKG changes (after one-half hour) were observed. A slight drop in blood pressure was noted in previously hypertensive patients. Isoproterenol's short duration of effects is ideal and one or two inhalations spaced four hours apart may be safely recommended for the relief of the acute asthma paroxysm.