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The results of the recording of respiratory symptoms and the measurement of lung function in 136 male postal workers employed as mail carriers were studied. In addition, the prevalence of chronic respiratory symptoms in 87 male noexposed control workers was also examined. There was a significantly higher prevalence of chronic bronchitis (25.0%) and sinusitis (38.9%) in mail carriers than in control workers (13.8%; P

Confectionery workers are exposed to a wide variety of organic dusts and aerosols. Previous studies with workers in a confectionery plant working with cocoa and rye flour indicate that these workers are at risk of developing adverse respiratory symptoms and lung function impairment. The effects of cocoa and rye flour extract on isolated guinea pig tracheal smooth muscle were studied using water-soluble extracts from cocoa and rye flour obtained from the studied confectionery plant. Dose-related contractions of nonsensitized guinea pig tracheal rings were demonstrated using both cocoa and rye flour extracts. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with drugs known to modulate smooth muscle contraction: atropine, indomethacin, pyrilamine, nordihydroguaiaretic acid (NDGA), acivicin, bromophenacyl bromide (BPB), 3,4,5-trimethoxybenzoate 8-(N,N-diethylamino)octyl ester (TMB8), captopril, and capsaicin. Constrictor effects of the dust extracts were inhibited by these agents, the pattern of which depended on the dust extract. Atropine consistently and significantly reduced the contractile effects of both extracts. These observations suggest a release of parasympathetic mediators by these extracts or more directly an interaction with muscarinic receptors. In addition, the constrictor effect of cocoa and rye flour extracts was significantly, but only partially, reduced by indomethacin, pyrilamine, BPB, and TMB8. Acivicin also partially decreased the constrictor effect of cocoa extract. Pretreatment of tracheal tissue with capsaicin also decreased the constrictor effects of high concentrations of cocoa and rye flour extracts. Data suggest that cocoa and rye flour extracts cause a dose-related constriction of airway smooth muscle by non immunological mechanisms involving cholinergic pathways and airway mediators such as histamine and the products of the arachadonic acid cascade. This effect is not dependent on the presensitization of guinea pigs.

Karelia air-pollution. Malodorous sulfur-compounds. Lung-function. Pulmonary-function. Mill workers. Occupational asthma. New-hampshire. Pulp-mills. Dust. Mortality. The respiratory function and Immunological status of workers employed in the paper recycling industry were studied. The mean age of the 101 studied workers was 41 years, and the mean duration of their exposure was 17 years. A group of 87 unexposed workers of similar age, duration of employment, and smoking history was studied for the prevalence of chronic respiratory symptoms. Lung function in the paper workers was measured by recording maximum expiratory flow volume (MEFV) curves and recording forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and maximum expiratory flow rates at 50% and the last 25 % of the FVC (FEF50, FEF25). Immunological studies were performed in all 101 paper workers and in 37 control workers (volunteers). These included skin-prick tests with paper-dust extracts and other nonoccupational allergens, as well as the measurement of total serum immunoglobulin E. Significantly higher prevalences of all chronic respiratory symptoms were found in paper compared with control workers (P < 0.01). The highest prevalences were found for chronic cough (36.6%), chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), and dyspnea (18.8%). Occupational asthma was diagnosed in four(4.0%) of the paper workers. A logistic regression analysis performed on chronic respiratory symptoms of paper workers indicated significant effects of smoking and exposure, with the smoking effect bring the most important. Multivariate analysis of lung-function parameters indicate significant effects of exposure. For paper workers, the measured FEF50 and FEF25 were significantly decreased, compared with predicted values, suggesting obstructive changes located primarily in smaller airways. Among 101 tested paper workers, 16 (15.8%) had positive shin-prick tests to at least one of the paper extracts ; none of the control workers reacted to these extracts. increased serum IgE levels were found in 21% of the paper workers and in 5 % of control workers (P < 0.05). Paper workers with positive skin-prick tests to any of the paper and/or other tested extracts had higher prevalences of chronic respiratory symptoms and lower measured lung-function tests compared with predicted than did those with negative skin-prick tests, but the differences were not statistically significant. The measured concentrations of total and respirable dust in this industry were higher than those recommended by Croatian standards. Our study suggests that work in the paper-recycling industry is associated with respiratory impairment and that sensitive workers employed in this industry may be at particular risk of developing chronic respiratory abnormalities

Many extracellular matrix proteins contain the tripeptide sequence arginine-glycine-aspartate (RGD). This RGD motif is recognized by integrins, a family of adhesion receptors present on vascular smooth muscle cells. In the present study, we examined the ability of different RGD-containing peptides to affect the contraction of rat aortic rings in response to different agonists. We found that the peptide RGDS inhibited angiotensin-induced contraction in a dose dependent manner. In contrast, the peptides RGDW and RGES had no effect on angiotensin-induced contractility. We show that function-blocking antibodies to the integrins alphavbeta3 and alpha5beta1 also inhibit angiotensin-induced contraction. These effects were observed in the absence of an intact endothelium. In contrast, neither an antibody directed against the beta1 subunit nor the peptide RGDS had an effect on phenylephrine or 5-hydroxytryptamine-induced contraction. These data suggest that interactions of vascular smooth muscle with components of the surrounding extracellular matrix may influence the response of smooth muscle to agonists.

We studied 233 male workers employed in two brick-manufacturing plants and 149 matched control workers. The mean age of the brick workers was 35 years, with a mean duration of employment in this industry of 16 years. The prevalence of chronic respiratory symptoms as well as acute symptoms during the work shift were recorded. Lung function was measured on Monday during the work shift by recording maximum expiratory flow-volume (MEFV) curves, from which the forced vital capacity (FVC), the one-second forced expiratory volume (FEV1) and flow rates at 50% and the last 75% of the FVC (FEF50, FEF75) were measured. The results of periodic chest roentgenograms were reviewed. There was a significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%), and chest tightness (24.0%) in exposed workers, compared with control workers (20.1%; 18.1%; 0%) (P < 0.05). This increased symptom frequency was also documented among nonsmokers studied by age and by length of employment, suggesting a work-related effect. Among work shift-related symptoms, high prevalences were noted for upper respiratory tract symptoms (e.g., dry throat, eye irritation, throat irritation). The measured FVC and FEV1 were significantly lower than predicted for brick workers and suggested a restrictive pattern. The mean FVC (as a percent of predicted) was 78.1% and FEV1 was 88.1%. The FEF50 and FEF25 were not significantly decreased. A multiple regression analysis with age, exposure, and smoking as predictors and lung function parameters as response variables showed a significant effect between exposure and FVC. Significant chest roentgenographic abnormalities were not documented. These findings of a restrictive lung function pattern in brick workers with normal chest roentgenograms may suggest early interstitial disease. Additionally, a bronchitic component, as suggested by the respiratory symptoms, may also be present.

Latex manufacturing workers are exposed to a heterogeneous aerosol of organic compounds. Previous studies of latex workers involved in glove production indicate that these individuals are at risk of developing respiratory symptoms and impaired lung function. The effect of latex extracts on isolated guinea pig tracheal smooth muscles was studied using latex water-soluble extracts obtained at different stages of the industrial process. Latex extracts were prepared as a 1:10 (w/v) solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using two latex extracts (latex 1 and latex 2). Latex 1 was prepared from the native latex and latex 2 from a processed form of latex which was relatively free of soluble proteins. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with drugs known to modulate smooth muscle contraction: atropine, indomethacin, pyrilamine, nordihydroguaiacetic acid, acivicin, trimethobenzoic acid and capsaicin. Constrictor effects of the dust extracts were inhibited by a wide variety of these agents. Atropine consistently and strikingly reduced the contractile effects of these extracts. This observation may suggest an interaction of the extracts with parasympathetic nerves or more directly with muscarinic receptors. Inhibition of contraction by blocking other mediators was less effective and varied with the dust extract. Pretreatment with capsaicin did not change the constrictor effects of latex 1 but enhanced the effects of latex 2. Depletion of neuropeptides, however, did not reduce the constrictor effect. We suggest that latex extracts cause dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on the presensitization of guinea pigs.

The effect of paper dust collected at two different locations in a paper recycling plant (PD1 and PD2) on isolated nonsensitized guinea pig tracheal smooth muscle was studied in vitro. Dust extracts were prepared as a 1:10 w/v aqueous solution. Dose-related contractions of guinea pig tracheal rings were elicited with both PD1 and PD2. Pharmacologic studies were performed with atropine (10(-6) M), indometacin (10(-6) M), pyrilamine (10(-6) M), LY171883 (10(-5) M), nordihydroguaiaretic acid (10(-5) M), and TMB8 (10(-5) M). The possible role of endogenous neuropeptides in this constrictor process was studied by depleting neural mediators with capsaicin (5 x 10(-6) M) before challenge with dust extracts. Constrictor effects were partially inhibited by a wide variety of the mediator blocking agents. The effects of both extracts were almost totally inhibited by the anticholinergic agent atropine, suggesting that a principal pathway mediating this response may involve the parasympathetic nervous system. The intracellular calcium-blocking agent TMB8 also induced a reduction of the contractile responses to PD1 and PD2 consistent with the well established role of intracellular calcium in smooth muscle constriction. Pretreatment with capsaicin significantly increased the contractile activity of paper dust extracts but only at the higher doses of these extracts. This suggests that the effect of paper dust is not initiated by the release of mediators stored in sensory nerves but that the prerelease of these mediators may enhance the constrictor effects of these dusts. We suggest that paper dust extracts cause dose-related airway smooth muscle constriction possibly associated with the release of cholinergic as well as other mediators. The constrictor effect does not require tissue presensitization or the release of neuropeptides from sensory nerves.

The prevalence of acute and chronic respiratory symptoms and lung-function changes was studied in a group of 81 municipal sanitation workers. In addition, the prevalence of chronic respiratory symptoms and lung function was studied in 65 control workers. There were significantly higher prevalences of all chronic respiratory symptoms among the sanitation workers than among the control workers. Sanitation workers (smokers and nonsmokers) 40 years of age or older had higher prevalences of all chronic respiratory symptoms than younger workers. In addition, sanitation workers (both smokers and nonsmokers) employed for 10 years or longer had significantly higher prevalences of chronic respiratory symptoms than control workers. There was also a high prevalence of acute symptoms, which developed among the sanitation workers during work shifts. Of these symptoms, prevalences were highest for dryness of the nose and throat, followed by throat and eye irritation. Lung-function testing demonstrated significantly diminished forced vital capacity (FVC) and 1-second forced expiratory volume (FEV 1 ) for the 81 sanitation workers compared with control values. These differences only become significant after 10 or more years of employment in the sanitation industry and were not entirely explained by smoking. These differences were smaller and not statistically significant for maximum flow rates at 50% and the last 25% of the vital capacity. Our data suggest that sanitation workers-particularly those with long periods of work exposure-may develop acute and/or chronic respiratory symptoms accompanied by decreases in lung function (primarily FVC and FEV 1 ).

Our study investigated a group of 216 wool textile workers (158 women and 58 men). Respiratory symptoms were assessed by questionnaire in wool textile workers and in 130 not exposed (control) workers. Ventilatory capacity was measured in wool workers by recording maximum expiratory flow-volume (MEFV) curves on Monday before and after the work shift. Forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and flow rates at 50% and the last 25% of the vital capacity (FEF50, FEF25) were measured on the MEFV curves. Analysis of the data demonstrated a significantly higher prevalence of all chronic respiratory symptoms in wool workers than in controls, being the highest in wool workers for nasal catarrh (M: 63.8%; F: 44.9%) and for sinusitis (M: 62.1%; F: 43.0%). A high prevalence of acute symptoms, associated with the work shift, was also noted in wool workers. Exposure to wool dust caused significant across-shift reductions of ventilatory capacity varying from 1.4% for FEV1 to 9.1% for FEF50. Textile workers exposed to wool for > 10 years in the workplace had similar across-shift reductions of ventilatory capacity tests as those with shorter exposures. In a large number of these wool workers, FEF50 and FEF25 were below 70% of predicted normal values. Smokers had acute and chronic lung function changes similar to those of nonsmokers, indicating that smoking did not account for all the respiratory effects seen in wool processing workers. Our data suggest that dust exposures in wool textile mills may be associated with the development of chronic respiratory symptoms and impaired lung function.

A 3-year follow-up study was performed on 38 women and 28 men from the originally studied textile workers employed in a soft hemp processing mill. Acute and chronic respiratory symptoms and ventilatory capacity were recorded during the cross-sectional and the follow-up studies. Maximum expiratory flow-volume (MEFV) curves were obtained on these workers, and forced vital capacity (FVC), 1-second forced expiratory volume (FEV1) and flow rates at 50% and at 25% of the VC (FEF50, FEF25) were measured. High prevalences of acute and chronic respiratory symptoms persisted at the follow-up study. In particular, high prevalences of byssinosis were documented at both studies (women: 47.4% and 47.4%; men: 64.3% and 67.9%, respectively). Statistically significant mean across-shift reductions were recorded for all ventilatory capacity tests at the initial study. A large mean annual decline was calculated for FEV1 in women and for all ventilatory capacity parameters in men; these declines were greater for workers with symptoms of byssinosis than for those without. The accelerated decline in FEV1 noted in the women workers, who were predominantly nonsmokers, suggests an independent hemp effect. Exposures in the work environment were measured with Hexhlet filters and revealed very high dust concentrations (mean total: 21.4 mg/m3, 22.4 mg/m3; respirable: 8.4 mg/m3, 9.9 mg/m3) at both initial and follow-up studies. These levels are much higher than those found in mills processing organic materials in North America. Our data demonstrate that work in the hemp industry, particularly in small poorly regulated mills, continues to have deleterious effects on respiratory function.

A cross-sectional study of respiratory function was performed in 50 sisal textile workers in 1972. Twenty of the 50 sisal workers still employed in the sisal mill were reexamined 19 years later. At the time of the initial study there were higher prevalences of all chronic respiratory symptoms in sisal compared with control workers. By the time of the follow-up study a significant increase had occurred in almost all chronic respiratory symptoms among the 20 sisal workers. At the time of the initial study there were similar and statistically significant across-shift reductions of forced vital capacity (FVC) and the 1-s forced expiratory volume (FEV1) on Monday and the following Thursday of the work week. Across-shift reductions in FVC and FEV1 in the 20 sisal workers at the follow-up study were larger than at the first measurement. Two sisal workers out of 20 (10.0%) had a positive skin test reaction to an extract sisal; both related symptoms of occupational asthma. In two sisal workers (10.0%) increased IgE was measured; one of these had symptoms of occupational asthma. Our data suggest that exposure to sisal dust in the textile industry may, in some workers, cause the development of respiratory difficulties. Immunological testing may be of value in identifying such workers at risk for occupational asthma.

Respiratory findings were studied in a group of 135 female and 32 male workers employed in greenhouses. In addition 51 women and 30 men were studied as a control group. Exposed women had significantly higher prevalences of chronic cough, dyspnea, chest tightness, and rhinitis (P < 0.01) than the controls. Among the men, only rhinitis was more prevalent in greenhouse workers (P < 0.01) than in controls. Smokers had higher prevalences of all chronic respiratory symptoms than nonsmokers, but the differences were statistically significant only for chronic cough and rhinitis in women and for chronic phlegm in men. There was a high prevalence of acute symptoms during work. A large number of greenhouse workers complained of skin reactions to plants and pesticides (women: 37.8%; men: 34.4%). Workers had significantly lower mean ventilatory capacity measurements (except in the case of forced vital capacity) when compared to standard predicted values. Smokers and nonsmokers had similar values of lung function expressed as percentages of the predicted values. Greenhouse workers exposed for more than 10 years had a significanty lower FEF25, measured as a percentage of the predicted value, than workers exposed for less than 10 years. Our data indicate that occupational exposure to greenhouses may be associated with the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.

Occupational exposure to oyster mushroom (Pleurotus ostreatus) has been associated with obstructive lung disease. Previously, we studied an extract of oyster mushroom (OME) and determined that it causes dose-dependent contractions of nonsensitized guinea pig trachea (GPT). We extend these studies to the investigation of sensitized tissue. In the present study 24 animals were sensitized using ovalbumin (OA) and subsequently challenged with an aerosol of 2.5% OA. A control group of 12 nonsensitized GPs was also studied. Tracheas were removed and were divided into rings in which the epithelium was retained (EP+) or removed (EP−). Dose-related contractions of sensitized and nonsensitized GPTs were elicited with OME. In nonsensitized animals the EP+ GPTs demonstrated a significantly greater response to OME (100–1000 μl) than did the EP− GPTs (p

A group of 35 men employed in the processing of animal food was studied to assess the relation between respiratory findings and immunological status. The most frequent positive skin prick reactions to occupational allergens were to fish flour (82.9%), followed by carotene (77.1%), corn (65.7%), four-leaf clover (62.9%), sunflower (54.3%), chicken meat (31.4%), soy (28.6%), and yeast (22.7%). Increased total IgE serum levels were found in 14/35 (40.0%) animal food workers compared to 1/39 (2.6%) in a healthy population (p less than 0.01). A significantly higher prevalence of chronic respiratory symptoms was found among the exposed workers compared to control workers. There was however, no significant difference in the prevalence of chronic respiratory symptoms between animal food workers with positive and negative skin tests to house dust or to fish flour or among those with increased or normal IgE (except for dyspnea). The frequency of acute symptoms associated with the work shift was high among the animal food workers but similar by immunological status. There were significant mean across-shift reductions for all ventilatory capacity tests, being particularly pronounced for FEF25. Workers with positive skin tests to fish flour antigen had significantly larger across-shift reductions in FEF25 than workers with negative skin reactions. An aqueous extract of animal food dust caused a dose-related contractile response of isolated guinea pig tracheal muscle in vitro. Our data suggest that, in addition to any immunological response animal food dust may produce in vivo, it probably also causes direct irritant or pharmacological reactions on the airways as suggested by our in vitro data.

Immunological parameters were studied in a group of 24 cotton textile workers. These were volunteers from a cohort of 106 (83 women and 23 men) previously studied textile workers. A group of 30 employees from a bottle packing plant served as a control for the immunologic studies. The subgroup of volunteers undergoing immunologic testing did not differ from the original cohort of textile workers in age, sex, smoking history, or prevalence of most chronic respiratory symptoms, nor were there any significant differences in baseline lung function or across-shift changes. The 24 cotton worker volunteers underwent skin testing with extracts of cotton dust and cotton seed. Eight of these 24 (33.3%) had positive tests, and 5 of the 8 had elevated serum immunoglobulin E (IgE) levels. Only one of the 8 skin-test-positive workers had symptoms of byssinosis. Only 1 of 30 control workers' skin tested with cotton extract reacted, and none had an increased serum IgE level (P less than 0.01). Both baseline lung function and across-shift changes did not differ between workers with positive and negative skin test reactions or between workers with normal and elevated IgE levels. Additionally, we studied the response in vitro of nonsensitized guinea pig trachea to cotton bract extract and demonstrated a dose-dependent contractile response. These data suggest that while immunological findings are frequent in textile workers, they correlate poorly with respiratory symptoms and function and may not be the basis for the airway obstruction seen in this disease.

We studied 42 women occupationally exposed in the fur manufacturing industry (mean age: 34 years, mean duration of exposure: 11 years). The highest prevalence of positive immediate skin reactions to antigen of animal hair was found for marten (10%), followed by fox and lamb (7%), mink (5%), and Chinese lamb, domestic fox, and Chinese calf (2%). Precipitating antibodies were demonstrated for lamb (17%), astrakhan (14%), mink, domestic fox and skunk (12%), Chinese lamb (10%), and Chinese calf (7%). Increased total IgE was found in 9.5% of subjects. Chronic symptoms were consistently more prevalent among workers with positive skin tests and positive precipitins than among workers with negative tests. A high prevalence of acute symptoms during the work shift was found among furriers. The prevalence of these symptoms was higher among workers with positive precipitating antibodies than among those with negative studies but not for workers with positive skin tests. Mean acute reductions in ventilatory capacity over the work shift were recorded for most ventilatory parameters. In general, greater drops in respiratory parameters occurred in individuals with positive precipitins (e.g., FEV1: -6.5% vs. -2.8%; positive vs. negative precipitins) but not in those with positive skin tests. Our study suggests that workers in the fur manufacturing industry develop acute and chronic respiratory problems often associated with specific indicators of atopy.

Immunological and respiratory findings were studied in a group of 19 male soybean workers. Twenty control workers also participated in the immunological studies. All soybean workers had positive immediate skin reactions to soybean extract, as did 19/20 control workers. Similarly, 18/19 soy workers reacted to soy antigen prepared after separation from oil, but only 3/19 to soy lecithin antigen and 1 to soy oil antigen. A majority of soy workers (13/19) reacted to house dust. Only 3/19 soy workers had increased levels of soy-specific IgE. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being significantly different for dyspnea (P less than 0.01). Workers with increased specific serum IgE or positive skin tests to house dust did not have any more symptoms than workers with negative tests. Ventilatory function was significantly worse in soybean workers than expected. Nevertheless, workers with positive skin or serological tests to house dust had across-shift changes similar to those with negative tests. These data suggest that skin and airway responses to soybean components (particularly the non-lipid ones) are very frequent among soybean workers. In the current study specific (soy) and non-specific (house dust) skin tests and immunoglobulins did not allow us to identify the workers at risk of developing symptoms or lung function abnormalities. This suggests that in addition to any atopic mechanisms, the irritant effect of soy dust may play a role in this occupational airway disease.

Respiratory symptoms and abnormalities of lung function were studied in 84 female and 27 male hemp workers employed in two textile mills (A and B) processing soft hemp (C sativa). In mill A 46 women and 27 men were investigated and 38 female workers were studied in mill B. Forty nine women and 30 men from a non-dusty industry served as controls. A significantly higher prevalence of almost all chronic respiratory symptoms was found in female hemp workers when compared to control workers. Among the men these differences were significant for nasal catarrh and sinusitis. A high prevalence of byssinosis was found among female hemp workers in both mills (group A, 47.8%; group B, 57.9%) as well as in the male workers (66.7%). Statistically significant across shift reductions in lung function were found for all ventilatory capacity measurements in female and male hemp workers varying from 7.1% for forced expiratory volume in one second (FEV1) to 15.1% for flow rates at 50% vital capacity (FEF50). Measured Monday baseline values before the work shift were significantly lower than expected for hemp workers, being particularly reduced for FEF25 and FEF50. The data suggest that occupational exposure to hemp dust is a significant risk factor for the development of acute and chronic lung disease in workers employed in this textile industry.

Mushroom farm workers suffer from respiratory symptoms during the farming of mushrooms. The objective of this study was to analyze the effects of oyster mushroom (Pleurotus ostreatus) extract (OME) on isolated guinea pig tracheal smooth muscle in vitro. Isolated guinea pig tracheal tissue from 27 nonsensitized guinea pigs were studied. The OME was obtained from indoor mushroom growing fields and prepared as a 1:10 w/v aqueous solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using these extracts. The OME contained significant quantities of bacterial components (eg., endotoxin: 43,072.92 EU/mg). Parallel, pharmacological studies were performed by pre-treating the tissues with mediator-modifying agents including atropine, indomethacin, pyrilamine, BPB, acivicin, NDGA, captopril, TMB8 and capsaicin. Atropine consistently and strikingly reduced the contractile effects of this extract. These observations suggest an interaction of the OME with parasympathetic nerves or more directly with muscarinic receptors. Pretreatment with TMB8 (inhibitor of intracellular calcium mobilization) also significantly blocked the constrictor effect of OME, indicating a role of calcium mobilization in the constricting effect of OME. Inhibition of contraction by blocking of other mediators was less effective and varied depending on the drug. We conclude that OME causes a dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on pre-sensitization of the guinea pigs.

In this review we describe characteristics of occupational airway diseases, as well as physical and chemical characteristics of agents inducing airway disease. Occupational airway diseases include industrial bronchitis, reactive airway dysfunction syndrome, bronchiolitis obliterans, and occupational asthma. High- and low-molecular weight substances associated with occupational airway disease are listed. The importance of host factors is stressed. Diagnostic approaches, particularly indicators for specific challenge testing with occupational materials, are described. Preventive and control measures are presented.

In this cross-sectional study, the prevalence of acute and chronic respiratory symptoms and lung function were investigated in 236 (169 male and 67 female) livestock farmworkers raising domestic animals, including cattle and horses. The prevalence of acute and chronic respiratory symptoms was recorded by administering a modified version of the British Medical Research Council questionnaire on respiratory symptoms. Lung function was measured by recording the maximum expiratory flow-volume curves from which the forced vital capacity, the one-second forced expiratory volume, and the maximum expiratory flow rates at 50% and the last 25% were measured. There was a significantly higher prevalence of almost all chronic respiratory symptoms in farmers compared with controls: highest among men for chronic cough (27.2%) and highest among women for dyspnea (28.3%). Typical symptoms of occupational asthma were diagnosed in 3.6% of the male and 1.5% of the female livestock farmers. A logistic regression analysis performed on chronic respiratory symptoms of livestock workers indicate significant effects of smoking (P < 0.001) on all symptoms except occupational asthma. A large number of male and female livestock farmworkers complained of acute work-related symptoms: highest for dry cough (52.2%) and shortness of breath (44.9%). Lung function data among these workers demonstrated a trend toward lower lung function in general. Multivariate analysis of lung function parameters indicate significant effects of length of employment and smoking in male and length of employment in female livestock farmworkers. The data suggest that employment in livestock farming may be associated in a dose-dependent manner with the development of acute and chronic respiratory symptoms and lung function changes.

This investigation was designed to study respiratory problems in farmworkers. To better define the consequences of this work environment on respiratory health, 814 farmworkers (738 male and 76 female) were studied. The mean age of the men in this study was 38 years, and the mean duration of their employment was 15 years. For women, the mean age was 44 years and the mean duration of their employment was 10 years. Of the men, 56.5% were regular smokers, and 23.7% of the women were regular smokers. A group of 635 control workers without significant exposure to air pollutants were matched by sex, age, employment, and smoking habit. The prevalence of chronic symptoms among male farmworkers was greater (P0.01) than among male control subjects for chronic cough (24.8% vs 11.4%), chronic phlegm (22.8% vs 9.1%), and chronic bronchitis (20.1% vs 7.4%). Among women farmworkers, a significant difference was noted with controls for chest tightness (farmworkers, 21.1%; control subjects, 0%; P0.001). There was a high prevalence of acute symptoms among male and female farmworkers. In particular, farmworkers complained of more frequent cough, eye irritation, dyspnea, and throat irritation than did control subjects. For respiratory symptoms in male and female farmworkers, odds ratios were generally significant for smoking, age, and duration of employment. Ventilatory capacity tests were significantly reduced for farmworkers compared with predicted values. Regression analysis of ventilatory capacity tests in male farmworkers as a percentage of predicted values demonstrated significant coefficients for employment and smoking. Our data suggest that farmworkers are exposed to noxious agents that cause respiratory symptoms and ventilatory capacity impairment.

Background Occupational exposure to respiratory irritants may effect respiratory function in workers exposed to ambient air pollutants in the workplace. Methods We studied 567 male and 135 female workers employed in two chemical plants in Zagreb, Croatia. Measurements of the ambient concentrations of air pollutants were performed. The mean age of the men was 37 years and mean duration of employment was 12 years; a majority of these workers were smokers. The mean age of the women was 37 years with a mean duration of employment of 14 years; only one-third of the women smoked. An unexposed group of 340 male and 110 female unexposed workers was also studied. Acute and chronic work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. Results There were higher prevalences for all chronic respiratory symptoms in exposed than in unexposed workers particularly among women, a majority of which were nonsmokers. Occupational asthma was recorded in three (0.5%) of the men and in two (1.5%) of the women workers. Logistic regression analysis indicated that the presence of chronic respiratory symptoms among exposed workers was primarily associated with the amount of smoking. Additionally, there were high prevalences of acute symptoms during the work shift. Among the chemical workers these were greatest for eye irritation (male: 43.9%; female: 51.9%), dryness of the throat (male: 43.4%; female: 57.0%) and irritation of the throat (male: 37.4%; female: 56.6%). Ventilatory capacity data among the chemical workers demonstrated that most of the measured tests, particularly the FVC and FEV1 were significantly decreased compared to predicted (P

Chronic obstructive pulmonary disease (COPD) is a worldwide problem causing prolonged and progressive morbidity as well as premature mortality. Pharmacologic treatment consists primarily in the relief of symptoms and preventing or minimizing the consequences of exacerbations. Central to the pharmacologic management of COPD is the use of bronchodilator therapy. Two major classes of agents are frequently used: β-adrenoceptor agonists and antimuscarinic agents. These drugs are used mainly in the inhalational form, primarily as rescue medication, but occasionally for maintenance in combination therapy. The availability of "ultra-long"-acting β-adrenoceptor agonists and long-acting antimuscarinic agents opens the way for combinations of these agents to be used in maintenance therapy. Such a combination offers the potential of enhanced efficacy due to additive effects and better compliance as the result of once-daily treatment. This article reviews the rationale for current bronchodilator therapy of COPD as well as the current status of a fixed-dose combined inhaler using two novel long-acting agents: glycopyrronium bromide and indacaterol maleate.

A group of 343 workers (252 males and 91 females) employed in four poultry farms in Croatia was studied for the prevalence of acute and chronic respiratory symp forms and lung function changes. There were significantly higher prevalences of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness in poultry workers than in control workers. Male poultry workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than poultry workers who were nonsmokers (P < 0.01). Poultry workers exposed for more than 10 years had significantly higher symptoms prevalences than those workers with shorter exposures (except among female smokers). There was also a high prevalence in poultry workers of acute symptoms which developed during the work shift. The measured FVC, FEV1, and FEF25 in poultry workers were significantly lower than predicted normal values. Workers exposed for more than 10 years had lower ventilatory capacity tests (expressed as percentage of predicted) than those workers with shorter exposures. Changes in FEV1, FEF50, and FEF25 were less pronounced than in FVC. Additionally we showed that a water-soluble poultry dust extract obtained from this workplace caused a dose-related contraction of nonsensitized guinea pig tracheal smooth muscle when studied in vitro. Pharmacologic studies of this response indicate that it may result from the release of multiple endogenous mediators. Our data suggest that work in poultry farms may, for some workers, cause the development of acute and chronic respiratory symptoms and lung function changes.

Wool mill workers develop respiratory symptoms and lung function abnormalities associated with their work in the textile industry, As in other workplaces, which process organic materials, the dust generated in the manufacture of wool has been implicated as a cause of these respiratory problems. Pharmacologic studies of wool dust extract were performed in vitro on guinea pig tracheal (GPT) segments. A wool dust extract (WDE) was prepared from material collected from a mill previously surveyed. When the standardized WDE solution was added to an organ bath in increments of 10, 30, 100, 300, and 1000 μl it caused a consistent, dose-dependent constriction of GPT. Pretreatment of guinea pig tracheas, prior to WDE challenge, with atropine (10 −6 M), pyrilamine (10 −6 M), indomethacin (10 −6 M), verapamil (10 −6 M), TMB8 (10 −6 M), BW755C (10 −6 M), and LY171883 (10 −6 M) was studied in order to evaluate receptor-dependent and -independent characteristics of WDE-induced constriction. WDE-induced bronchoconstriction was partially inhibited by the antihistamine pyrilamine. Atropine and leukotriene inhibitors (LY171883 and BW755C) were not found to have a significant protective effect on WDE-induced constriction. Both TMB8 and verapamil (intra- and extracellular calcium blocking agents) suppressed the effect of wool dust extract in the range tested. These findings suggest that in this model, WDE-induced airway constriction is only partly attributable to common mediators of bronchoconstriction (e.g., histamine). The airway effects of WDE may be modulated by calcium channel blocking agents.

Acute and chronic respiratory symptoms as well as ventilatory capacity were studied in 116 bus drivers and 119 mechanics. Bus drivers and mechanics demonstrated a significantly higher prevalence of most chronic respiratory symptoms when compared to control workers. In particular, lower airway symptoms of chest tightness and dyspnea and upper airway symptoms of nasal catarrh were significantly more prevalent among drivers and mechanics than among controls. Bus drivers and mechanics who were smokers had significantly higher prevalences of respiratory symptoms than nonsmoking bus drivers. Bus drivers and mechanics employed for more than 10 years also exhibited higher frequencies of respiratory symptoms than those exposed for 10 years or less. Many of the workers complained of acute symptoms during the work shift. The ventilatory capacity data demonstrated lower values for all parameters, particularly FEF25, compared to control worker values as well as to predicted normal values, for bus drivers and mechanics who were smokers. Our data indicate that long-term employment in the transport industry of bus drivers and mechanics, particularly in combination with smoking, may be associated with the development of chronic respiratory symptoms and lung function impairment.

Respiratory symptoms and ventilatory capacity were studied in a group of 288 workers (259 women and 29 men) employed in a confectionery plant. A group of workers (96 women and 31 men) not exposed to confectionery manufacture were also studied as controls. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being greatest for confectionery workers exposed to the dust of flour, talc, and starch and the vapours of alcohol. Chronic bronchitis was reported by 7% of the women and 21% of the men, and chest tightness was reported by 27% of women and 66% of men. There was a high prevalence of acute irritative symptoms during the workshift in all groups of confectionery workers, especially for cough, dyspnoea, burning and dryness of the throat, and eye irritation. For all groups of confectionery workers there were statistically significant across shift reductions in ventilatory capacity, being most pronounced for maximum flow rate at 50% of the control vital capacity (FEF50; range 4.6-13.0%) and at 25% of the control vital capacity (FEF25; range 4.7-22.3%). Preshift values of FEF50 and FEF25 were significantly lower than predicted values. The data suggest that some workers employed in confectionery plants may develop acute and chronic respiratory symptoms associated with changes in lung function.

A group of 80 men employed in the glassblowing industry was studied in order to investigate the effect of this occupational exposure on respiratory function. Eighty nonexposed workers were included in the study as a control group. Glassblowers had a significantly higher prevalence of chronic bronchitis, nasal catarrh, chronic sinusitis, and nasal bleeding than control workers; length of employment in the industry did not affect the prevalence of symptoms. Many of the glassblowers complained of work shift related symptoms. Measurement of lung function among glassblowers showed there were significant increases in the forced vital capacity (FVC) and the maximum flow rates at 50% and 25% of FVC on maximum expiratory flow volume (MEFV) curves (FEF50, FEF25) across the work shift. Glassblowers had significantly larger preshift FVC and forced expiratory volume in 1-second (FEV1) measurements when compared to controls. Additionally, residual volume (RV) and RV/TLC% for the glassblowers were significantly increased while the diffusing capacity (DLCO) was normal (when compared to predicted values). Our data indicate that employment in the glassblowing industry contributes to the development of chronic respiratory findings.

Respiratory symptoms and ventilatory capacity were studied in a group of 74 sewage workers employed in cleaning the city sewage system of Zagreb, Croatia. Workers were studied by their work stations: closed channels (N = 26), drainage (N = 31), and other sewage workers (N = 17). The prevalence of chronic respiratory symptoms was higher in closed channel and drainage workers than in controls, particularly for chronic cough (range: 41.9-46.2% vs. 14.3%), chronic phlegm (range: 38.7-46.2% vs. 14.3%), chronic bronchitis (range: 32.3-42.3% vs. 8.6%), and chest tightness (range: 29.0-53.8% vs. 0%). In the first two groups of sewage workers there was a high prevalence of acute symptoms which developed during the work shift, being particularly pronounced for eye irritation (range: 16.1-26.9%), dyspnea (16.1-23.1%), dizziness (range: 6.5-23.1%), throat burning (9.7-19.2%), and skin irritation (range: 22.6-26.9%). Baseline ventilatory capacity was significantly decreased compared to predicted values in sewage workers; in particular, values for FEF50 and FEF25 were reduced, suggesting obstructive changes in smaller airways. Our data indicate that sewage workers experience frequent acute and chronic respiratory symptoms and exhibit objective evidence of respiratory dysfunction.

Exposure to aerosols of organic dusts such as coffee, tea, spices, soy, fur, and animal food in an occupational setting can affect the respiratory health of industrial workers. Based on our experience with workers from many small industries processing organic materials, we discuss the clinical features and possible mechanisms responsible for the respiratory impairment associated with these types of dust exposure. Significantly higher prevalences for most chronic respiratory symptoms were found among exposed workers than among control workers. Smoking appears to aggravate these symptoms. A large number of exposed workers complained of acute symptoms which developed during the work shift. In exposed workers, significant across-shift reductions in lung function were recorded for all spirometric tests, but particularly for the flow rates at 50% and 25% of vital capacity on maximum expiratory flow-volume curves. Comparison of preshift measured ventilatory capacity tests with predicted normal values indicates that these workers demonstrate obstructive changes affecting primarily flow rate at low lung volumes. The data suggest that exposure to organic aerosols in industrial settings, particularly in conjunction with smoking, may be associated with the development of chronic obstructive lung disease.

β-Adrenoceptor agonists are central to the management of chronic obstructive pulmonary disease (COPD). They contribute both as rescue medications and as controller agents. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines indicate that they are useful at all stages of the disease. Current use of β-adrenoceptor agonists emphasizes the rapidity of their onset of action and the duration of their effect. The development of newer agents seeks to improve these properties. Concern about the side effects of β-adrenoceptor agonists-has limited their use in asthma. In view of their potential for cardiovascular effects and the prevalence of comorbidities in COPD, careful attention needs to be given when using these agents in COPD patients.

A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes.

Lung cancer is a leading cause of mortality and morbidity in industrialized countries and potentially one of the most preventable cancers. The major cause of this neoplasm, cigarette smoking, has been well established since the 1950s. Legislative, regulatory and educational efforts have resulted in significant reductions in the number of smokers, decreasing the percentage of individuals who initiate the smoking habit and increasing the number of persons who quit. Nevertheless, there is wide recognition of the need to address the issue of lung cancer prevention for those who are addicted to cigarettes or who are exposed to lung carcinogens in other ways. Strategies for smoking cessation now include nicotine replacement, and modulation of central nervous system addictive mechanisms through neuropharmacology. For those who have experienced prolonged carcinogen exposure a growing number of novel strategies based on epidemiologic observations as well as oncologic principles are under investigation. Many promising avenues have been proposed and while no agent is yet approved as chemopreventive for lung cancer a growing number of these agents are being tested as primary, secondary and tertiary prevention strategies. Proposed primary prevention strategies include cigarette abstinence and treatment of cigarette addiction, using appropriate cancer screening methods, decreasing environmental exposure, and possibly vaccination. Proposed secondary prevention strategies include methods for smoking cessation, lifestyle and diet modification, and modulation of molecular pathways that lead to lung cancer. Proposed tertiary prevention strategies include individually tailored therapies against certain molecular pathways as well as treatments to minimize disease metastasis and its sequelae. Currently, treatment for nicotine addiction includes nicotine replacement and medications such as bupropion and the recently approved varenicline. Attempts to modify the development of lung cancer have included the use of nutritional supplements such as beta-carotene, selenium, vitamin E and vitamin A. Conventional medications have also been suggested, including cyclooxygenase-2 inhibitors, aspirin and statins. Newer therapies that are being investigated for their potential preventative role against lung cancer include epidermal growth factor receptor inhibitors, monoclonal antibodies, tyrosine kinase inhibitors, farnesyl transferase inhibitors, peroxisome proliferator-activated receptor agonists, cell cycle inhibitors, and demethylating agents. This review discusses lung cancer, screening, and many of the different agents currently being investigated for their role in the prevention of this disease.

Exercise-induced asthma can appear as one of many forms of airway hyperreactivity or as a unique clinical entity. Simple spirometry confirms the suspected clinical diagnosis in most instances, although more sensitive measurements of airway obstruction may be required. In general, the asthmatic need not restrict physical activity because of exercise-induced attacks. The disease responds well to prophylactic management with a wide variety of antiasthmatic agents, such as theophylline preparations, beta-agonists, and cromolyn sodium.

SUMMARY Suppurative lung infections and the basic rules for their treatment have been recognized since antiquity. Currently a majority of these diseases are due to pneumonias associated with aspiration. When properly managed, these infections carry an excellent prognosis. In the debilitated host, nosocomial infections may lead to intractable suppuration with a high mortality and, therefore, the emphasis in these situations must be on prevention. The bacteriology of these diseases is often polymicrobial. Care must be taken in the collection of samples for culture not to contaminate them with material from the upper airways. Currently transtracheal collection of specimens offers the best method for obtaining tracheobronchial specimens. Finally, in the evaluation of pulmonary suppuration, the localization of infected material may be greatly enhanced by a careful study of the chest roentgenogram, the use of ultrasound, and possibly by CAT scanning.

A maximal lung inflation is known to alter airway tone in man. Recent investigations, examining how this phenomenon relates to bronchial provocation testing, suggest that a deep inspiration will decrease airway resistance and underestimate the subsequent decrement in lung function following airway challenge. Because the recovery of baseline tone is rapid following a deep inspiration, we evaluated the consistency of three consecutive partial and maximal expiratory flow-volume maneuvers performed at approximately 45- to 60-second intervals. Functional parameters including the forced expiratory volume in 1 s and the maximal expiratory flow at 60% of the vital capacity below total lung capacity on the partial curve (MEF40%P) were constant at each measurement point following induced bronchoconstriction or bronchodilation in both healthy and asthmatic subjects. We suggest that with 45 s between maneuvers, repeatable parameters can be attained from three consecutive flow-volume curves.

Immunological and respiratory findings were studied in a group of 45 female spice-factory workers (mean age: 39 years; mean exposure: 17 years). In addition a group of 45 female control workers matched by sex, age, and smoking habit were also studied. Intradermal skin testing with mixed spice dust allergen demonstrated positive skin reactions in 73.3% of exposed and in 33.3% of control workers (P less than 0.001). Increased IgE serum levels were found in 36.8% of exposed and in 9.7% of the control workers (P less than 0.01). The prevalence of chronic respiratory symptoms was significantly higher in the exposed workers than in the control workers (P less than 0.01). There was, however, no consistent correlation between skin reactivity and chronic respiratory symptoms. There was a high prevalence of acute symptoms during the work shift. These complaints were more frequent in workers with positive skin tests for the symptoms of cough, chest tightness, and irritated and dry throat. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. There were statistically significant mean reductions during the work shift for all measured lung function parameters in workers with positive skin reactions. In those workers with negative skin reactions only FEF50 and FEF25 reached statistical significance. Aqueous extracts of different spices (chilli pepper, paprika, caraway, coriander leaves, coriander seeds, cinnamon, ginger, onion, curry, and parsley) caused a dose-related contractile response of isolated guinea pig tracheal smooth muscle. These data suggest that immunologic reactions to spices are frequent in spice workers and may be related to acute symptoms and lung function changes, but not to chronic changes. The data further suggest that, in addition to any immunologic response these spices may produce in vivo, they probably also provoke direct irritant reactions in the airways as suggested by in vitro data.

Respiratory function was studied in a group of 29 soy workers exposed to soy bean dust produced after extraction of soy oil. The prevalence of all chronic respiratory symptoms was consistently higher in exposed than in control workers, although the differences were not statistically significant. During the Monday work shift there was a significant mean acute across-shift decrease in maximum expiratory flow rates at 50% and 25% vital capacity (FEF50: -6.4%; FEF25: -12.4%). Changes in vital capacity (FVC: -3.6%) and 1-sec forced expiratory volume (FEV1: -2.7%) were smaller, but still statistically significant. There were also statistically significant acute reductions in all ventilatory capacity parameters over the work shift on the following Friday, although the changes were in general smaller than on Monday (except for FEV1). An analysis of Monday preshift values of ventilatory capacity in soy bean workers suggests that exposure to soy bean dust may lead to chronic respiratory impairment in some workers.

A group of 71 men employed in animal food processing was studied to assess the prevalence of acute and chronic respiratory symptoms and the presence of lung function abnormalities. In addition, a control group of 55 unexposed men was studied for the prevalence of chronic respiratory symptoms. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed workers compared to the control workers. Those workers who smoked had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than the smokers in the control group. For nonsmokers, the differences between exposed and control workers were significant for chronic phlegm and chest tightness. The frequency of acute symptoms associated with the work shift was high among the animal food workers. There were significantly lower measured values for FVC, FEV1, and FEF50 in the exposed group (smokers and nonsmokers) compared to predicted lung function values. In smokers, all measured parameters of ventilatory capacity were significantly less than predicted; for nonsmokers, the FVC and FEV1 were less than normal. Our data indicate that exposure to dust in the animal food industry may be associated with the development of acute and chronic respiratory symptoms and the impairment of lung function. Smoking, in this setting, appears to aggravate these changes.

The prevalences of acute and chronic respiratory symptoms and lung function changes were studied in a group of 806 workers working in a "clean environment." Acute symptoms during the work shift were reported by smokers but were essentially absent in nonsmokers. Chronic respiratory-symptom prevalences were similar to those reported in community-based populations, with smokers experiencing more chronic symptoms than nonsmokers. Baseline lung function measurements indicated no significant differences with values obtained from prediction equations based on community populations. There were significant across-shift increases in all ventilatory capacity tests (forced vital capacity, 1-second forced expiratory volume, and maximum expiratory flow rates at 50% and the last 25% of the vital capacity) varying from +1.9% to +9.8% of the preshift values. Workers older than 40 years of age and those employed for more than 10 years had similar across-shift changes compared with younger workers and those with longer durations of employment. Our data indicate that workers in clean work environments (with the exception of smokers) complain of few acute or chronic respiratory symptoms and have normal lung function. These workers experience increases in lung function across the work shift, probably reflecting normal diurnal variation. Smokers, although significantly more affected than nonsmokers, do not appear to have work-related findings, and smoking appears to be the most significant risk factor for the development of lung disease in unexposed workers. In this study, community-based control data was equivalent to worker control data in unexposed workers.

The treatment of respiratory failure has spawned an empire of intensive-care units, specialized personnel, and sophisticated equipment. Although this growth shows no sign of slowing, some questions have been raised by regulatory agencies, and, more recently, by investigators, as to the impact on patient outcome of this impressive array of hardware. 1-3 Perhaps nowhere is this growth more evident than in the exponential increase in ventilator models that has occurred during the past ten years (Figure). From slow and hesitating steps, dating back to biblical times, assisted ventilation began blossoming in the 1930s with negative-pressure ventilators, in response to the respiratory problems of neuromuscular disease. With the waning of these disorders, the therapy for respiratory failure turned to that of obstructive lung disease problems, and, later, to the adult respiratory-distress syndrome. Positive airway pressure and modifications of the pressure waveform (eg, positive end-expiratory pressure [PEEP], intermittent mandatory ventilation [IMV]) were

The transcutaneous technique of measuring PO2 (tcPO2) was studied in 30 adults with normal cardiovascular function undergoing nitrous oxide-enflurane or nitrous oxide-fentanyl anesthesia to determine the relationship between tcPO2 and PaO2. The tcPO2 was an accurate and clinically useful trend indicator of PaO2 (r = 0.9; p less than 0.0001). The ability to detect trends was unaffected by the type of anesthetic agent used. The technique was less useful in predicting absolute values for PaO2 (r = 0.86). It is suggested that more widespread application of such monitoring awaits definitive development of a halothane-resistant electrode.

The transcutaneous technique of measuring carbon dioxide tension (tcPCO2) was studied in 30 adult neurosurgery patients undergoing nitrous oxide-enflurane or nitrous oxide-fentanyl anesthesia to determine the relationship between tcPCO2 and PaCO2. tcPCO2 was an accurate (r = 0.9) and clinically useful trend indicator of PaCO2. The ability to detect trends was unaffected by the type of anesthetic agent used. The technique was less useful in predicting absolute values for PaCO2 (r = 0.64). This technique may be particularly useful in situations in which control PaCO2 is essential to patient management.