Effects of oral cetirizine, a selective H1 antagonist, on allergen- and exercise-induced bronchoconstriction in subjects with asthma

The protective efficacy of oral cetirizine, a selective and potent H1-receptor antagonist, against the immediate bronchoconstrictive response to allergen inhalation and exercise challenge was evaluated in 16 subjects with stable, predominantly mild asthma. The subjects underwent double-blind, crossover pretreatments in randomized order in two separate protocols with (1) three daily oral doses of 20 mg of cetirizine and placebo, followed by allergen inhalation, and (2) single oral doses of cetirizine (5, 10, and 20 mg), albuterol (4 mg), and placebo, followed by exercise with cold-air inhalation. Cetirizine failed to decrease bronchial sensitivity to inhaled allergen in eight of 10 subjects. Neither cetirizine nor albuterol uniformly inhibited exercise-induced bronchoconstriction. Serum concentrations of cetirizine were consistent with systemic H1-blocking activity. Modest bronchodilation occurred after administration of cetirizine and albuterol before exercise but not after the third dose of cetirizine in the allergen protocol. One subject developed moderate drowsiness during multiple dosing with cetirizine. Thus, cetirizine, in the doses studied, is not uniformly effective in preventing allergen- or exercise-induced bronchoconstriction. Histamine is one of many mediators participating in immediate asthmatic responses, and selective H1 antagonists do not completely block these airway events. However, cetirizine may still clinically benefit some patients with asthma, such as patients with allergic rhinitis or urticaria.

Effects of inhaled thiazinamium chloride on histamine-induced and exercise-induced bronchoconstriction

The protective efficacy of aerosolized thiazinamium chloride (TC) against histamine-induced and exercise-induced bronchoconstriction was evaluated in 15 subjects with stable, mild asthma. Following reproducible bronchoprovocation with these stimuli, each subject underwent randomized, double-blind, crossover pretreatment with single doses of nebulized TC (300, 600, and 900 micrograms), placebo, and an active control drug (metaproterenol or cromolyn), followed by histamine or exercise challenge (two separate protocols). The results indicated that all doses of TC significantly blocked histamine-induced bronchoconstriction as compared with placebo. Overall, aerosolized TC was ineffective in blocking exercise-induced bronchoconstriction, although 900 micrograms TC tended to be more effective than placebo. Thiazinamium (900 micrograms) produced a modest bronchodilator effect. No clinically significant adverse effects related to TC occurred. We conclude that aerosolized TC is effective in attenuating histamine-induced but not exercise-induced bronchoconstriction in the doses studied. Further studies are warranted to evaluate the role of TC in asthma therapy.

Antibody-dependent cellular cytotoxicity mediated by lung macrophages: a comparison of two target cells

Mononuclear cell-mediated cytotoxicity may be an important cellular immune function in host lung defense. Prior investigators have shown that lung macrophages participate in cell cytotoxicity which is antibody-dependent (ADCC). We tested the hypothesis that alveolar macrophages share some cell surface receptors for the Fc portion of IgG, i.e., Fc receptors, similar to those found on circulating monocytes in order to function in ADCC. Hence, ADCC mediated by autologous human blood monocytes and lung macrophages was studied by measuring the release of chromium-51 from prelabeled target erythrocytes coated with IgG. Alveolar macrophages were obtained from healthy adult subjects by bronchoalveolar lavage and tested against two different erythrocyte target cells to measure ADCC activity. Our results show significant activity by alveolar macrophages demonstrated against chicken erythrocytes at a target to effector cell ratio of 2:1 or 10:1 and with an antibody concentration of 1:100 or 1:400 (volume per volume, p less than 0.05, Student's test). However, when a peripheral blood monocyte specific target cell (human type B erythrocyte) was utilized, alveolar macrophages were not as capable of significant ADCC activity against these monocyte-specific target cells. The inability of lung macrophages to function in ADCC against other target cells (i.e., human type B erythrocytes) unlike the peripheral blood monocytes suggests that some Fc receptors are not shared. In other words, these different cell types share IgG receptors but differences in activity may be due to some changes in the Fc portions of IgG due to cellular differentiation. The use of these target cells may potentially be useful in functionally discriminating between two types of adherent autologous mononuclear cells (lung macrophages vs. blood monocytes).

Diagnostic efficacy of a nasotracheal protected specimen brush in patients with suspected bacterial pneumonia

The diagnostic yield and safety of a novel nasotracheal protected specimen brush (PSB) were evaluated in 15 nonintubated adult patients with suspected bacterial pneumonia. A double-catheter PSB was passed directly through the anesthetized nose and into the trachea without bronchoscopy or fluoroscopy. Endotracheal brushing was performed in less than 10 sec, and the brush was immediately processed for Gram staining and quantitative aerobic and anaerobic cultures. According to clinical follow-up and response to therapy, 11 episodes of bacterial pneumonia and five cases of nonbacterial lung disease were established. The PSB Gram stain confirmed lower respiratory sampling in all cases. The PSB cultures indicated respiratory pathogens in 9/11 (82%) cases of pneumonia, with greater than 10(3) colony-forming units (cfu)/ml in all but two specimens. All patients with pneumonia responded to specific antibiotics. All patients with nonbacterial disorders had PSB cultures of less than 10(3) CFU/ml, and their pulmonary processes improved without antibiotic therapy. The procedure was well tolerated, although two patients had transient bronchospasm or apnea. Experience with the nasotracheal PSB is limited, but the procedure appears to be a reliable and relatively safe alternative diagnostic method in selected patients with suspected bacterial pneumonia. Quantitative cultures are necessary to improve its diagnostic accuracy.

Human and rabbit newborn lung macrophages have reduced anti-Candida activity

Bronchoalveolar macrophages (BAM) protect the adult lung from low level microbial contamination. The antimicrobial activity of human newborn BAM is unknown. BAM were isolated from effluents of suctioned, intubated newborns and from bronchoalveolar lavage of healthy, nonsmoking adult volunteers. An in vitro cytologic slide assay was developed and used to ascertain: 1) inhibition of intracellular filamentation of Candida albicans (active yeast growth) and 2) killing + digestion of ingested C. albicans. The ability to restrict intracellular yeast filamentation was markedly different for human newborn versus adult BAM. Adult BAM were five times more effective in restricting intracellular filamentation of Candida compared to newborn cells (p less than 0.01). Nonfilamented ingested yeast were also handled differently by newborn and adult macrophages. Nonfilamented yeast were killed and digested by adult BAM at a rate that was 2.5 times above that noted in neonatal lung macrophages (p less than 0.005). However, no differences were found in the total number of killed + digested Candida within human newborn and adult BAM [adult = 32.4 +/- 10.5% (n = 5), newborn less than 1200 g = 39.6 +/- 16.8% (n = 8), and newborn greater than 1200 g = 30.2 +/- 11.1% (n = 16), mean +/- S.D.]. Neonatal BAM were able to destroy C. albicans at a level equivalent to adult cells because these newborn phagocytes allowed intracellular Candida to enter a state of active growth, thereby rendering the yeast more susceptible to killing and digestion. The anti-Candida activity noted in lung macrophages recovered from normal 1-day-old and adult rabbits was similar to that seen in human BAM.(ABSTRACT TRUNCATED AT 250 WORDS)

Metered-dose inhaler usage in subjects with asthma: comparison of Nebulizer Chronolog and daily diary recordings

The Nebulizer Chronolog (NC) is a portable electronic device that attaches to standard metered-dose inhalers (MDIs) and records and stores the date and time of each MDI actuation. We evaluated the long-term performance of the NC and compared its data to concurrent recordings of self-administered MDI usage in daily diaries. Eighty-three subjects with asthma were evaluated during a 7 1/2-month panel study of air pollution effects. Although 44 (53%) of the NCs developed a malfunction during the study, the average total (+/- SD) percentage of useful days with functioning NCs was still 86 +/- 18% (median 93%). The agreement between the daily diary and NC recordings was very high, that is, 50 (67%) of 75 subjects had perfect agreement. Eighteen subjects with over or under diary reporting were detected. We conclude that the NC is an effective, objective, accurate, and continuous monitor of daily MDI usage despite some remediable technical problems. The NC can facilitate the evaluation of short- and long-term medication usage patterns and compliance issues in MDI-related research and clinical settings.

Enhancement of exercise performance with inhaled albuterol

The use of bronchodilators in athletic competition has allowed asthmatics to participate successfully in competitive events. Little information exists regarding possible bronchodilator use by non-asthmatic competitive athletes. Fifteen non-asthmatic cyclists participated in a double-blind, randomized, cross-over protocol involving a simulated race, i.e., one-hour heavy continuous exercise (minute ventilation (VE) 81 L/min BTPS) followed by maximal effort workload to exhaustion, with/without prior inhalation of albuterol to see if their exercise performance would be acutely altered. Each study day metabolic parameters were obtained four times. Pulmonary function tests were performed prior to and after the inhalant (albuterol/placebo) and following exercise. There was a significant increase in forced expiratory flow parameters following albuterol. Although not significant, oxygen uptake (VO2) and VE were smaller during the one-hour submaximal test following albuterol and VO2max and VEmax were higher. There was an increased ride time (196 vs. 159 s; p less than 0.05). Albuterol may provide a competitive advantage for non-asthmatic athletes who might use it.

Inhaled albuterol does not protect against ozone toxicity in nonasthmatic athletes

We evaluated the acute prophylactic efficacy of albuterol aerosol in protecting nonasthmatic athletes from the untoward effects of 0.21 ppm ozone (O3) on symptoms, pulmonary function, exercise performance, and post-exposure histamine bronchoprovocation. Fifteen trained competitive cyclists participated in a randomized crossover study consisting of double-blinded inhalations of albuterol (180 micrograms) and placebo approximately 30 min prior to heavy continuous exercise (minute ventilation, [VE] greater than or equal to 80 L/min) for 60 min, followed by a maximal sprint (peak VE greater than 140 L/min) until exhaustion. Each subject was exposed randomly to either 0.21 ppm O3 or filtered air (FA) during the four single-blinded exposure sessions. Albuterol pretreatment resulted in modest but significant bronchodilation as compared to placebo. However, albuterol did not prevent O3-induced respiratory symptoms, decrements in forced vital capacity (FVC), forced expired volume in one second (FEV1.0), and maximum midexpiratory flow rate (FEF25-75%), and positive histamine challenges as compared to that with placebo/O3. There were no statistically significant differences in the metabolic data or ride times across all drugs and exposures, although the peak VE was significantly lower with O3 than FA (142.3 vs. 150.7 L/min, respectively) regardless of drug. The results indicate that acute pretreatment with inhaled albuterol is unable to prevent or ameliorate O3-induced symptoms and alterations in pulmonary function and exercise performance. The contribution of beta-adrenergic mechanisms in the acute airway responses to O3 appears to be minimal.

Cetirizine inhibition of histamine-induced bronchospasm

Cetirizine is a potent, selective H1 antagonist recently made available for investigation. To evaluate this oral drug's efficacy in treating asthma, we examined the bronchodilator effects of 5-, 10-, and 20-mg doses as well as the protective effects of these doses against histamine-provoked bronchospasm. Cetirizine's efficacy was compared with that of a placebo and oral hydroxyzine (25 mg) in 10 patients with mild asthma. The new compound provided significant protection in a dose-dependent manner against histamine-induced bronchospasm. A 25-mg oral dose of hydroxyzine, which is partially metabolized to cetirizine, yielded blood levels of cetirizine comparable to those attained with 5 mg of oral cetirizine. Hydroxyzine 25 mg conferred greater protection against histamine bronchoprovocation than placebo, but it gave less protection than 10- and 20-mg doses of cetirizine. Cetirizine in all doses, as well as hydroxyzine at 25 mg, produced significant bronchodilation. However, the bronchodilator effect of the 25-mg hydroxyzine dose was less than that of cetirizine at 20 mg. In this short-term study, no significant side effects of cetirizine were noted.

Respiratory effects of cocaine "freebasing" among habitual users of marijuana with or without tobacco

Use of cocaine by smoking its alkaline precursor ("freebasing") has become increasingly prevalent. Recent studies of small numbers of cocaine users suggest that freebasing frequently causes cough, dyspnea, and abnormalities in diffusing capacity (DCO), although these findings could have been due to concomitant use of other drugs. We therefore evaluated the relationship between cocaine use by freebasing and chronic respiratory symptoms and lung dysfunction in a large sample of habitual smokers of marijuana with or without tobacco who denied intravenous drug abuse. The findings suggested that, among habitual marijuana smokers, "moderate" cocaine smoking damaged both large and small airways, as reflected by functional changes that were independent of concomitant marijuana use and appeared to be synergistic with the effects of tobacco. On the other hand, no adverse influence of cocaine smoking on the pulmonary microcirculation was demonstrated in our sample of freebase users.

Tracheobronchial changes in habitual, heavy smokers of marijuana with and without tobacco

We performed flexible fiberoptic bronchoscopy in 29 habitual, heavy marijuana smokers 25 to 45 yr of age, with and without concomitant tobacco smoking, to inspect and biopsy their proximal tracheobronchial tree for the evaluation of histopathologic changes. Control tobacco smokers (TS) and nonsmokers (NS) residing in the same metropolitan area were similarly studied and compared with the marijuana smokers (MS) and marijuana-tobacco smokers (MTS). Respiratory and drug histories, physical examination, and pulmonary function tests were obtained prior to bronchoscopy. The prevalence of respiratory symptoms and pulmonary function abnormalities was generally higher in the 3 smoking groups than in the NS group but was not statistically different across all groups. However, bronchoscopic inspection revealed airway hyperemia and other visible abnormalities in 32 (91%) subjects in the 3 smoking groups, unlike the unremarkable findings in the NS group. Light microscopy showed 2 or more histopathologic changes in the bronchial epithelium of all MS, MTS, and TS. Squamous metaplasia was observed in all MTS, a prevalence that was significantly different from that in MS, TS, and NS. Hyperplasia of basal and goblet cells was more prevalent in the MS than in the NS, whereas cellular disorganization was more prevalent in the MS than in the TS. A direct relationship between cumulative marijuana use (joint-years) and bronchoscopic and histopathologic changes was not apparent in this study sample. These results indicate that relatively young, habitual, heavy marijuana smokers have a high prevalence of abnormal airway appearance and histologic findings, irrespective of concomitant tobacco smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cetirizine, a new histamine H1 antagonist, on airway dynamics and responsiveness to inhaled histamine in mild asthma

Cetirizine, a major human metabolite of hydroxyzine, preserves the histamine H1-antagonist activity of the parent compound but poorly penetrates the blood-brain barrier, thus minimizing sedative and anticholinergic effects. In 10 young (mean age 27.7 years) subjects with mild asthma (FEV1 greater than 70% predicted), we evaluated the bronchodilator and protective efficacy of 5, 10, and 20 mg of cetirizine against bronchospasm induced by histamine inhalation (0.03 to 20 mg/ml) in comparison with placebo and hydroxyzine, 25 mg, using a random, double-blind crossover design. The provocative concentration of histamine causing a 20% decline in FEV1 for all 10 subjects from the postdiluent control value was more than fourfold greater after each active drug than after placebo. Cetirizine, 5 to 20 mg, provided significantly greater protection against histamine-induced bronchospasm than hydroxyzine (p less than 0.001); moreover, a dose-dependent protective effect was noted with cetirizine. Significant bronchodilation was also found: at 60 minutes, FEV1 increased significantly after all active antihistamines compared to placebo and after 20 mg of cetirizine compared to hydroxyzine (p less than 0.05). FEV1 increased significantly at 120 minutes after hydroxyzine and after cetirizine in both the 20 and 10 mg doses compared to placebo (p less than 0.05). We conclude that in subjects with mild asthma, orally administered cetirizine provides significant dose-dependent protection against histamine-induced bronchoconstriction, which in the doses studied is superior to that produced by the parent compound, hydroxyzine. In addition, cetirizine in 5 to 20 mg doses causes acute bronchodilation. These results suggest a possible role of cetirizine in asthma therapy.

Longitudinal changes in lung function and respiratory symptoms in progressive systemic sclerosis. Prospective study

Most patients with progressive systemic sclerosis (PSS) exhibit lung involvement. However, the natural history of lung disease in PSS remains poorly defined. To evaluate lung function over time in PSS, a battery of lung function tests were prospectively performed serially between 1973 and 1982 in 61 patients with PSS. Functional indexes of restriction (vital capacity and total lung capacity) and diffusion impairment (diffusing capacity) showed greater-than-expected annual rates of change. Male subjects showed a trend toward faster declines in forced vital capacity, forced expired volume in one second, total lung capacity, and functional residual capacity and a more rapid increase in static recoil pressure at 90 percent of total lung capacity than did female subjects. Nonsmokers had greater rates of decline in total lung capacity and static lung compliance (but not in forced vital capacity or diffusing capacity) and a greater rate of increase in static recoil pressure than did current and former smokers. Level of lung function at initial study visit, age, race, and chlorambucil therapy had no significant effect on the annual rates of change in lung function, whereas longer duration of disease prior to study entry was associated with a slower annual decrease in lung volumes. Between the first and last visits (mean interval 3.1 years, maximum nine years), the frequency of abnormality in pulmonary function test results showed significant change only in the diffusing capacity (60 percent increasing to 82 percent) and static lung compliance (40 percent increasing to 54 percent), whereas the frequency of respiratory symptoms showed little change. These findings indicate an overall indolent progression of PSS-related lung disease, with substantial individual variability.

Differential examination of bronchoalveolar lavage cells in tobacco cigarette and marijuana smokers

Cells derived from bronchoalveolar lavage (BAL) were obtained from 19 healthy non-smokers (NS) and from 43 healthy smokers of tobacco and/or marijuana. Thirteen subjects smoked tobacco cigarettes only (TS) (mean +/- SE: 17.4 +/- 5.5 pack-years). Thirty subjects smoked marijuana; of these, 14 smoked marijuana only (MS) (149.1 +/- 102.7 joint-years) and 16 smoked marijuana and tobacco (MTS) (43.3 +/- 7.2 joint-years and 18.4 +/- 3.2 pack-years). Cell counts were expressed as total number recovered and as number of cells per milliliter of BAL fluid returned. Cell differentials were performed on Giemsa-stained cytopreps. Total cell number was significantly increased in the MTS, TS, and MS compared with that in the NS (p less than 0.01). Heavy tobacco smoking (greater than 10 pack-years) was associated with higher total cell numbers in BAL than was light tobacco smoking (less than 10 pack-years). The MTS had a higher total BAL cell yield per milliliter than did the TS or the MS (p less than 0.004). Marijuana smoking had a significant effect on cell yield independent of the presence or absence of concomitant tobacco smoking (p less than 0.05). Macrophages were the predominant cells in the BAL of TS, MS, and MTS, as well as in the BAL of NS (greater than or equal to 90%). The number of neutrophils (as total recovered or per milliliter of BAL fluid) was significantly higher in the BAL fluid of all MTS and TS than in that of NS (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory symptoms and lung function in habitual heavy smokers of marijuana alone, smokers of marijuana and tobacco, smokers of tobacco alone, and nonsmokers

To evaluate the possible pulmonary effects of habitual marijuana smoking with and without tobacco, we administered a detailed respiratory and drug use questionnaire and/or lung function tests to young, habitual, heavy smokers of marijuana alone (n = 144) or with tobacco (n = 135) and control subjects of similar age who smoked tobacco alone (n = 70) or were nonsmokers (n = 97). Mean amounts of marijuana and/or tobacco smoked were 49 to 57 joint-years marijuana (average daily number of joints times number of years smoked) and 16 to 22 pack-years of tobacco. Among the smokers of marijuana and/or tobacco, prevalence of chronic cough (18 to 24%), sputum production (20 to 26%), wheeze (25 to 37%) and greater than 1 prolonged acute bronchitic episode during the previous 3 yr (10 to 14%) was significantly higher than in the nonsmokers (p less than 0.05, chi square). No difference in prevalence of chronic cough, sputum production, or wheeze was noted between the marijuana and tobacco smokers, nor were there additive effects of marijuana and tobacco on symptom prevalence. We noted significant worsening effects of marijuana but not to tobacco on specific airway conductance and airway resistance (tests of mainly large airways function) in men and of tobacco but not of marijuana on carbon monoxide diffusing capacity and on closing volume, closing capacity, and the slope of Phase III of the single-breath nitrogen washout curve (tests reflecting mainly small airways function) (p less than 0.03, two-way ANCOVA). No adverse interactive effects of marijuana and tobacco on lung function were found.

Impaired exercise performance and pulmonary function in elite cyclists during low-level ozone exposure in a hot environment

We evaluated the effects of low concentrations of ozone on the exercise performance and pulmonary function of 17 top-caliber endurance cyclists under conditions simulating competition and realistic temperature (31 degrees C). Each subject was randomly exposed to filtered air (FA), 0.12 and 0.20 ppm O3 on separate days in an environmental chamber. Each subject attempted to maintain submaximal exercise on a cycle ergometer equivalent to approximately 70% of maximal oxygen consumption (VO2max) for 60 min, followed by incremented (maximal) exercise until exhaustion. During submaximal exercise, average minute ventilation (VE) (89 L/min), VO2 (51 ml/min/kg or 72% VO2max), work load (260 W), and work time (57 min) were similar across all exposures. During maximal exercise, average peak VE (150 L/min), VO2 (68 ml/min/kg), work load (382 W), and ride time (263 s) were similar between 0.12 ppm O3 and FA. However, significant reductions in peak VE (18%), VO2 (16%), tidal volume (22%), work load (8%), and ride time (30%) occurred in 0.20 ppm O3 compared with those in FA. Postexercise decrements in forced expired volume in one second (FEV1) averaged 5.6% and 21.6% in 0.12 and 0.20 ppm O3, respectively. Ozone-related symptoms were mild in 0.12 ppm O3 but intensified and probably limited maximal performance in 13 subjects in 0.20 ppm O3. Changes in carbon monoxide diffusing capacity (adjusted for alveolar volume) were not significant across exposures. Nine subjects showed histamine hyperresponsiveness (i.e., greater than 20% decrease from the control postdiluent FEV1) after exposure to 0.20 ppm O3 as compared with 1 subject in 0.12 ppm O3.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchodilator effects of caffeine in coffee. A dose-response study of asthmatic subjects

Although caffeine is a universal drug and has multiple pharmacologic and physiologic actions in man, there are surprisingly few objective data about its effect on pulmonary function. We conducted a short-term, double-blind, randomized crossover study in nine asthmatic adults who ingested decaffeinated coffee containing varying amounts of added caffeine (mean of 0.2,2.5,5.6, and 7.2 mg/kg of body weight) on different days. The subjects also ingested decaffeinated coffee and aminophylline (200 mg) on a separate day of study. Baseline and post-drug determinations of serum levels of caffeine and theophylline, forced expired volume and flow, specific airway conductance (Gaw/VL), vital signs, and reported symptoms were obtained. Peak increases in serum caffeine concentrations (mean, 12.4 micrograms/ml +/- 1.5 micrograms/ml) occurred 45 minutes following the highest dose of caffeine (7.2 mg/kg), whereas the peak theophylline level (mean 3.8 micrograms/ml +/- 0.4 micrograms/ml) occurred 90 minutes following oral administration of aminophylline (mean theophylline, 2.6 mg/kg). Comparable peak increases in the forced expiratory volume in one second (FEV1), the forced expiratory flow during the middle half of the forced vital capacity (FEF25-75%), and Gaw/VL occurred at 120 minutes following aminophylline and the highest dose of caffeine, indicating that caffeine is an effective bronchodilator but is only 40 percent as active as an equivalent molar dose of theophylline. Regression analysis revealed statistically significant dose-response relationships between peak increases in serum caffeine concentrations and increases in FEV1, FEF25-75%, and Gaw/VL from baseline values. These findings have diagnostic and therapeutic implications regarding the use of caffeine prior to tests of pulmonary function and as a dietary agent, alone or in combination with theophylline.

Bedside bronchoalveolar lavage for the diagnosis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome

We studied the utility of bronchoalveolar lavage (BAL) as the primary diagnostic procedure in 46 separate episodes of suspected Pneumocystis carinii pneumonia (PCP) in 42 patients with AIDS. 35 procedures were performed at the bedside. A separate group of 40 historical controls with AIDS and suspected PCP had transbronchial biopsy (TBB) as the primary procedure. At least 100 cc of saline in 50 cc aliquots was used for BAL. Specimens were processed using rapid silver methenamine, Papanicolau, and Ziehl Neelson stains with appropriate cultures. There were 29 positives and 17 true negatives for PCP with BAL, confirmed by biopsy in 11, and using clinical criteria in 6. Accuracy, sensitivity, and predictive value of a negative result were all 100%. There was no significant difference in yield between TBB and BAL (p greater than 0.10). BAL was useful to diagnose other opportunistic organisms including CMV, atypical mycobacteria, and fungi. The frequency of isolates in the TBB group were comparable. TBB was complicated by 4 episodes of major bleeding. The data indicate that bedside BAL is effective, and safer than TBB in patients with AIDS and suspected PCP. We advocate BAL as the primary diagnostic procedure which can be performed at the bedside in patients with suspected PCP and AIDS. The high accuracy and predictive value of a negative BAL for PCP suggests confirmatory procedures may not be necessary in many cases.

Percutaneous needle lung aspiration for diagnosing pneumonitis in the patient with acquired immunodeficiency syndrome (AIDS)

Fourteen patients with acquired immunodeficiency syndrome (AIDS) or suspected AIDS underwent percutaneous needle lung aspiration (PNLA) for evaluation of 16 occurrences of acute pneumonitis. A 22-gauge spinal needle was passed 2 to 3 times in the area of greatest radiographic involvement under fluoroscopic guidance. The specimen was immediately placed on microscope slides for Gomori's methenamine silver and Papanicolaou staining. The needle was then flushed with sterile water for bacterial, Legionella, viral, mycobacterial, and fungal cultures, and for Legionella immunofluorescent staining. Diagnostic information was provided by 14 of the 16 procedures. Of 11 patients ultimately found to have P. carinii pneumonitis, PNLA specimens were diagnostic in 10 (91%). Infectious agents other than P. carinii also were identified by PNLA, including cytomegalovirus (4 cases), M. avium-intracellulare (1 case), and pyogenic bacteria (3 cases). Complications of PNLA were: pneumothorax in 7 cases (44%), 3 (19%) of which required chest tube evacuation; and minor hemoptysis (less than 50 ml) in 2. The PNLA can be a useful diagnostic procedure in the patient with AIDS and pneumonitis. It has the advantages of being less costly and time-consuming than fiberoptic bronchoscopy. It is, however, frequently complicated by pneumothorax, making it an inappropriate approach for patients with significant respiratory compromise.

Exercise-induced bronchodilation in asthma

Of 34 symptomatic adult asthmatic patients (23 men) aged 51 +/- 13 years (mean +/- 1 SD) with moderately severe airways obstruction who underwent maximal exercise testing at room temperature (22 degrees C) and humidity (44 percent RH) using a bicycle ergometer, we identified seven male patients aged 56 +/- 9 years in whom forced expired volume in one second (FEV1) increased greater than or equal to 20 percent over the baseline pre-exercise value (exercise-induced bronchodilation). At maximal exercise, these patients achieved an O2 consumption of 1.4 +/- 0.4 L/min and a minute ventilation of 56 +/- 9 L/min. Baseline FEV1 was 1.3 +/- 0.5 L (SD) (43 +/- 12 percent predicted) and increased to 2.1 +/- 0.5 L at five minutes after exercise and persisted at least 20 minutes. Exercise was repeated in all seven patients on a separate day one to six months later, and results were similar in six. In these seven patients, three minutes of voluntary isocapnic hyperventilation achieving a minute ventilation comparable to that during maximal exercise led to an increase in FEV1 of 20 +/- 18 percent (range 0 to 54 percent). The Vmax50 was 22 +/- 30 percent before, and 10 +/- 21 percent after maximal exercise and 25 +/- 37 percent before, and 11 +/- 22 percent after isocapnic hyperventilation. Pre-treatment with acetylsalicylic acid (mean serum concentration 120 +/- 64 micrograms/ml) in the six patients with reproducible bronchodilation completely blocked exercise bronchodilation in one patient and blunted it in four others. Findings suggest that a subset of adult patients with symptomatic asthma may develop bronchodilation after six to eight minutes of exercise, that exercise-induced bronchodilation may in part be reproduced with isocapnic hyperventilation, and that it may be blocked completely or partially by acetylsalicylic acid, implying mediation by prostaglandins.

Hypoxia-altitude simulation test. Evaluation of patients with chronic airway obstruction

Increasing hypoxia with altitude ascent is a potentially serious problem for patients with hypoxemic chronic airway obstruction (CAO) at sea level. We developed a hypoxia-altitude simulation test (HAST) to assess acute cardiopulmonary responses to the inhalation of hypoxic gas mixtures (equivalent to the inspired oxygen tension (PO2) present at 5,000, 8,000, and 10,000 feet above sea level) alone and in combination with supplemental oxygen (O2). Twenty-two subjects with stable normocapnic CAO were studied at sea level with a computer-based system that measured on-line, breath-by-breath resting ventilatory and gas exchange variables. Subjects breathed 20.9% (baseline), 17.1, 15.1, 13.9, and 20.9% (recovery) O2, and measurements were obtained once a "steady state" was reached at each level. Steady-state arterial PO2 (PaO2) and O2 saturation, alveolar PO2, and alveolar-to-arterial PO2 gradient decreased markedly during successive hypoxic levels, whereas arterial carbon dioxide tensions decreased only modestly. Minute ventilation and heart rate during 13.9% O2 increased only 12 and 10% above baseline. Ten subjects had asymptomatic cardiac arrhythmias during the HAST. Supplemental O2 significantly improved nearly all physiologic indexes. Sea level PaO2 best predicted acute, resting altitude PaO2. Sea level PaO2 values of 68 and 72 mmHg successfully classified more than 90% of the subjects with a PaO2 greater than 55 mmHg at 5,000 feet and a PaO2 greater than 55 mmHg at 8,000 feet, respectively. A regression equation and nomogram were derived to estimate PaO2 at altitudes between 5,000 to 10,000 feet in patients with normocapnic CAO.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of the interview on ranking in the residency selection process

The authors evaluated semi-quantitatively the influence of the personal interview on the ranking of internal medicine residency applicants by teaching staff interviewers. Pre- and post-interview rankings of 236 student applicants were compared. Approximately a third of the applicants were ranked more favourably, a third less, and a third remained unchanged following the interview. The magnitude and implications of the post-interview changes in rankings are discussed. Although the interview is a controversial component of the residency selection process, the present study indicates that the interview experience can have a major influence on the interviewer of an applicant and the interviewer's ranking of an applicant in a training programme's match list.

Acute and subacute bronchial effects of oral cannabinoids

The bronchodilating activity of oral cannabinoids was evaluated in three double-blind experiments that involved the study of dose-response and interactive relationships and the potential development of tolerance. Data indicated that delta 8-tetrahydrocannabinol (delta 8-THC), cannabinol (CBN), and cannabidiol (CBD) in maximal doses of 75 mg, 1200 mg, and 1200 mg, respectively, did not induce significant dose-related physiologic effects in experienced marijuana smokers. delta 8-THC (75 mg) was, however, associated with bronchodilation, tachycardia, and peak highs less than that after delta 9-tetrahydrocannabinol (delta 9-THC). The combinations of CBN and CBD with low-dose delta 9-THC (5 mg) did not induce significant bronchodilation but did exert interactive effects on heart rate and "high." A 20-day study of daily delta 9-THC (20 mg), CBN (600 mg), and CBD (1200 mg) did not indicate tolerance or reverse tolerance to any drug. We conclude that delta 9-THC and, to a lesser extent, delta 8-THC, have acute bronchodilator activity but that CBN, CBD, and their combinations do not provide effective bronchodilation. The daily use of delta 9-THC was not associated with clinical tolerance.

Prevalence and clinical correlates of pulmonary arterial hypertension in progressive systemic sclerosis

Forty-nine patients with progressive systemic sclerosis who had undergone extensive studies including pulmonary artery catheterization as part of an ongoing prospective study of the natural course of progressive systemic sclerosis were evaluated. The overall prevalence of pulmonary arterial hypertension in this population of patients with progressive systemic sclerosis was 33 percent, and among 10 subjects with the CREST syndrome the prevalence of pulmonary hypertension was 50 percent. The relation between pulmonary arterial hypertension documented at catheterization and abnormal results of noninvasive studies suggesting pulmonary hypertension, including physical examination, chest x-ray, electrocardiography, echocardiography, single-breath diffusing capacity, and vital capacity, was studied. Diffusing capacity was significantly lower in those patients with definite pulmonary hypertension (mean pulmonary artery pressure of 22 mg Hg or more) compared with those with a normal mean pulmonary artery pressure, and a diffusing capacity below 43 percent of predicted showed the greatest sensitivity (67 percent) of any single diagnostic test in detecting definite pulmonary hypertension. Chest x-ray suggesting pulmonary hypertension was the least sensitive of the tests evaluated, but showed the greatest specificity (100 percent) in identifying patients with pulmonary hypertension. A classification matrix based on discriminant function analysis utilizing the combination of diffusing capacity below 43 percent of predicted and chest x-ray and electrocardiographic findings correctly identified 75 percent of patients with definite pulmonary hypertension and 97 percent of patients with a normal pulmonary artery pressure, but failed to identify correctly patients with mild pulmonary hypertension (mean pulmonary artery pressure of 20 mm Hg). These findings indicate that specific noninvasive studies are helpful in assessing the likelihood of normal or definitely elevated pulmonary artery pressures in patients with progressive systemic sclerosis, but patients with mild pulmonary hypertension are not likely to be identified by these noninvasive studies.

Repeat fiberoptic bronchoscopy in patients with recurrent, unexplained hemoptysis

Repeat fiberoptic bronchoscopy (FB) is indicated in patients with recurrent, unexplained hemoptysis to localize and/or diagnose the source of bleeding. The results of 34 bronchoscopies in 14 patients over a 6-year period were examined. 10 patients had 2 FBs each and 1 patient had 5 procedures at varying intervals. Only early FB detected active bleeding (12/25) early FBs) and localized a bleeding site (10/25). Definitive diagnoses (6/34 FBs) occurred only in patients with lung malignancy and were not necessarily influenced by the timing or frequency of FB. Clinical diagnoses and management were infrequently altered by each FB, except for management of malignancy. Thus, early, repeat FB in this diagnostically difficult group of patients contributes limited immediate information and minimally changes therapy in patients with nonneoplastic conditions. Despite these limitations, direct bronchial visualization by FB remains the most reliable standard available for localizing and, to a lesser extent, diagnosing the etiology of recurrent hemoptysis.

Comparison of bronchial effects of nabilone and terbutaline in healthy and asthmatic subjects

The acute bronchomotor effect of nabilone, a synthetic cannabinoid compound, was compared to that of terbutaline sulfate and placebo in six healthy and six asthmatic subjects. Bronchodilation following nabilone was intermediate between that of terbutaline and placebo in the healthy subjects but was equivalent to placebo in the asthmatics. We conclude that oral nabilone (2 mg) does not result in significant acute bronchodilation in patients with asthma.

Effect of pneumatic trousers on pulmonary function

Little information is available concerning the effect of pneumatic antishock trousers (PT) on pulmonary function. To examine this issue, we measured the effects of PT inflation on forced expired volumes, subdivisions of lung volumes, quasistatic lung compliance, single-breath diffusing capacity for carbon monoxide, and transdiaphragmatic pressure at resting lung volume in 10 healthy nonsmoking adults. All subjects were studied seated without PT, supine with PT uninflated, and supine with PT inflated to 100 mm Hg. When seated subjects assumed the supine position without PT inflation, significant reductions were found in the forced expired volume in 1 sec, in subdivisions of lung volume, total lung capacity (TLC), functional residual capacity (FRC), expiratory reserve volume (ERV) and in transdiaphragmatic pressure. However, PT inflation itself did not produce significant changes in any of the measured pulmonary indices except transdiaphragmatic pressure. We conclude that PT inflation in supine normovolemic individuals does not produce acutely significant alterations in lung function.

Residents' training goals in respiratory knowledge and skills: perspective of three parties

Medical residents, full-time respiratory teaching staff, and community-based doctors rated the importance of fifty-five respiratory training goals involving knowledge and skills necessary for the future practices of all medical residents. Residents also rated their perceived preparedness in these training areas. Intra- and inter-group analyses indicated that residents agreed more often, and consistently assigned more importance (94% of goals) to the training goals, than did the teachers and doctors. Although the residents considered themselves prepared for 69% of the training goals, they also had moderate intra-group disagreement. These results may reflect variable training experiences and/or institutional practices, but areas of less than adequate preparation were identified and can be corrected. The other two groups were in general agreement except regarding some clinical skills. This study offers possible explanations for the group responses and indicates the potential benefit for groups to discuss, identify, and survey training goals.

The value of open lung biopsy in the immunosuppressed patient

To evaluate the impact of the open lung biopsy on diagnosis and therapy in the immunosuppressed patient, 68 such patients managed at UCLA from 1975 to 1980 were reviewed. Most had hematologic malignancies, and all were severely immunosuppressed. The rates of surgical mortality (1 operative death) and morbidity were minimal. There were 10 diagnostic differences apparent when biopsy results were compared with autopsy findings in 28 autopsied patients. Therapy was initiated or modified in 19 patients on the basis of open lung biopsy. Forty-four patients lived 1 year or less, 14 for more than 1 year, and 10 were lost to follow-up. Of 42 patients with an untreatable disease on the basis of lung biopsy, 67% died and 33% lived to leave the hospital. Of 25 patients with a treatable disease, 56% died and 44% left the hospital. Of 28 autopsied patients, only 12 were receiving appropriate medication at time of death despite biopsy. The patient whose disease is generally characterized by brief survival like acute leukemia, and whose situation is most desperate, unfortunately benefits least from open lung biopsy. We conclude that this procedure has only a modest impact in the management of these critically ill patients and should be used conservatively.

Clinical efficacy of early and delayed fiberoptic bronchoscopy in patients with hemoptysis

We analyzed the records of 129 consecutive patients with hemoptysis to evaluate whether or not early (during hemoptysis or during the 48 h after hemoptysis stopped) fiberoptic bronchoscopy (FB) more frequently localized and/or diagnosed the source of bleeding and influenced clinical outcome than delayed FB (48 h or more after hemoptysis stopped). Patients were divided into 3 groups on the basis of their final diagnoses: neoplasm (31 patients), bronchitis/bronchiectasis (52 patients), and miscellaneous (46 patients). Although the likelihood of visualizing active bleeding (41 versus 8%) or its site (34 versus 11%) was significantly higher with early versus delayed FB, respectively, neither active bleeding nor a bleeding site were visualized in at least 60% of the 92 patients who underwent early FB. Definitive (endoscopic) diagnoses by early or delayed FB occurred primarily in patients with neoplasm. Clinical outcome based on the results of FB was not significantly different between the early and delayed groups. Thus, early, single FB was generally neither diagnostic nor therapeutically decisive in these patients with hemoptysis.

Alcohol-induced bronchospasm in an asthmatic patient: pharmacologic evaluation of the mechanism

A 23-year-old Asian with histamine-reactive asthma complained of recurrent chest tightness, nasal congestion and flushing immediately after drinking minimal amounts of alcoholic beverages. He was extensively studied to determine the possible mechanism of his alcohol-induced respiratory symptoms. Drinking of either beer or 95 percent ethanol in apple juice immediately provoked vasomotor signs and moderately severe bronchospasm (54 percent and 73 percent decreases in specific airway conductance, respectively), which spontaneously improved over 30 minutes and two hours, respectively. Intravenous and inhaled ethanol caused less bronchospasm than observed with oral ethanol, and recovery was rapid. Pretreatment with cromolyn sodium (inhaled or oral) and isoproterenol had no inhibitory effect on the alcohol-induced bronchoconstriction, whereas atropine, acetylsalicylic acid, cyproheptadine, and chlorpheniramine appeared to have a partial inhibitory effect. Approximately 70 percent inhibition was observed after chlorpheniramine. Observations in this patient suggest that the bronchoconstriction induced by alcoholic beverages is related to their ethanol content and may be related to formation or release of one or more bronchoconstrictor and vasoactive compounds, including a stimulant of histamine1-receptors. The route of ethanol administration may also influence the bronchospastic response.

Survey of hospital doctors' training goals in diagnosis and management of pulmonary diseases

Although subspecialty training goals for junior hospital doctors have not been evaluated, they are potentially useful for assessing clinical competence. A questionnaire was sent to medical residents, full-time pulmonary teaching staff, and community-based physicians who were asked to rate the importance of diagnosing and managing selected pulmonary diseases for the future practices of young hospital doctors. The latter also rated their perceived preparedness for the same training goals. Generally good intra- and intergroup agreement about the relevance of most of the training goals was observed, although the hospital doctors rated a greater number of items to be more important than did the two other groups. This finding may be attributed to institutional influences and to many clinical abilities expected of all physicians. Immunological or fibrotic and paediatric respiratory disorders were rated least important by most respondents. The hospital doctors disagreed on the basis of the distribution of their ratings about their preparedness for the same goals, which probably reflects varying training experiences and background. The process of developing general professional training goals in a subspecialty requires discussion, identification, and consensus to identify and potentially correct areas of weakness, with allowance for institutional training patterns. A survey such as described in this study can provide data that can help measure clinical competence and support or define curricular changes.

Silicosis due to intentional inhalation of abrasive scouring powder. Case report with long-term survival and vasculitic sequelae

Silicosis due to inhalation of abrasive scouring powder is now an unusual event. We report a nonindustrial case of acute silicosis due to intentional inhalation of commercial, silica-containing scouring powder. This case is unique in that the patient had a 20 year survival (after onset of symptoms) with typical roentgenographic and histopathologic changes of silicosis, and evidence of immune complex disease in extrapulmonary tissues.

Adult respiratory distress syndrome after venous air embolism

Venous air embolism is not commonly believed to produce the adult respiratory distress syndrome. We present a nonsurgical case of venous air embolism followed by the development of this syndrome. Other causes of adult respiratory distress syndrome were excluded. Physicians should be alerted to its possible occurrence and the need for appropriate therapy.