Exercise intensity determines and climatic conditions modify the severity of exercise-induced asthma

Bronchial hyperresponsiveness in childhood: A narrative review

Bronchial hyperresponsiveness (BHR) is an important but not asthma-specific characteristic and can be assessed by direct and indirect methods, based on the stimulus causing airway obstruction. BHR has been proposed as a prognostic marker of asthma severity and persistence, and may also be used to control pharmacological management of asthma. The most recent data on the prevalence and development of BHR in childhood and its predictive value for subsequent asthma development in late adolescence and adulthood is discussed in this review. According to the BHR-related scientific articles written in the English language and indexed in the publicly searchable PubMed database, the prevalence of BHR varies based upon the methods used to assess it and the population examined. In general, however, BHR prevalence is reduced as children grow older, in both healthy and asthmatic populations. While asthma can be predicted by BHR, the predictive value is limited. Reduced lung function, allergic sensitization, female sex, and early respiratory illness have been identified as risk factors for BHR. The collective studies further indicate that BHR is a dynamic feature related to asthma, but asymptomatic BHR is also common. Ultimately, the prevalence of BHR varies depending on the population, the environment, and the evaluation methods used. While both the methacholine challenge and the exercise test may predict asthma in adolescence or early adulthood, the predictive value is higher for the methacholine challenge compared to the exercise test. The collective data presented in the present study demonstrate how BHR develops through childhood and its relation to bronchial asthma.

Air quality and temperature effects on exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) is exaggerated constriction of the airways usually soon after cessation of exercise. This is most often a response to airway dehydration in the presence of airway inflammation in a person with a responsive bronchial smooth muscle. Severity is related to water content of inspired air and level of ventilation achieved and sustained. Repetitive hyperpnea of dry air during training is associated with airway inflammatory changes and remodeling. A response during exercise that is related to pollution or allergen is considered EIB. Ozone and particulate matter are the most widespread pollutants of concern for the exercising population; chronic exposure can lead to new-onset asthma and EIB. Freshly generated emissions particulate matter less than 100 nm is most harmful. Evidence for acute and long-term effects from exercise while inhaling high levels of ozone and/or particulate matter exists. Much evidence supports a relationship between development of airway disorders and exercise in the chlorinated pool. Swimmers typically do not respond in the pool; however, a large percentage responds to a dry air exercise challenge. Studies support oxidative stress mediated pathology for pollutants and a more severe acute response occurs in the asthmatic. Winter sport athletes and swimmers have a higher prevalence of EIB, asthma and airway remodeling than other athletes and the general population. Because of fossil fuel powered ice resurfacers in ice rinks, ice rink athletes have shown high rates of EIB and asthma. For the athlete training in the urban environment, training during low traffic hours and in low traffic areas is suggested.

Asthma in patients climbing to high and extreme altitudes in the Tibetan Everest region

OBJECTIVES

The aim of this study was to investigate the behavior of asthma in patients traveling to high and extreme altitudes.

METHODS

Twenty-four Dutch patients with mild asthma did a trekking at high and extreme altitudes (up to 6410 m = 21030 ft) in the Tibetan Everest region. Asthma symptoms, use of asthma medication, symptoms of acute mountain sickness, spirometry, peripheral oxygen saturation, and heart rate were measured at 1300 m (baseline), and at 3875, 4310, 5175, and 6410 m. Asthma symptoms were assessed by means of a modified version of the Asthma Control Test. Symptoms of acute mountain sickness were scored by the Lake Louise self-report questionnaire. The expedition staff, consisting of seven healthy persons, acted as a control group.

RESULTS

In both asthmatics and controls, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) decreased with increasing altitude, whereas FEV1 as percent of FVC (FEV1%FVC) did not change. In both groups, peak expiratory flow (PEF) increased with increasing altitude. In general, differences in spirometric values between asthmatics and controls were not significant. Asthma symptoms did not change with increasing altitude. During ascent, less than half of the asthma patients increased their medication use. According to the Lake Louise score, no acute mountain sickness occurred, except for in the asthma group at 6410 m, which showed mild acute mountain sickness at that altitude. As expected, peripheral oxygen saturation decreased with increasing altitude in asthmatics and controls, differences between the two groups not being significant. In general, heart rate (at rest) did not change with altitude, except for an increase in asthmatics at 6410 m.

CONCLUSIONS

These results suggest that traveling to high and extreme altitudes is safe for patients with mild asthma.

Athletic trainers' experience and comfort with evaluation and management of asthma: a pilot study

BACKGROUND

Approximately 10% to 50% of competitive athletes experience asthma symptoms with exercise, due to either chronic asthma or exercise-induced bronchospasm. Early recognition and management of asthma symptoms may improve athletic performance and quality of life for athletes with asthma or exercise-induced bronchospasm. Athletic trainers may have frequent opportunities to identify asthma symptoms and assist athletes with management.

OBJECTIVE

To survey athletic trainers about their experience and comfort with evaluation and management of asthma symptoms in athletes and identify athletic trainer characteristics associated with higher comfort levels.

DESIGN AND SETTING

A 2005 cross-sectional survey of National Athletic Trainers' Association and Illinois Athletic Trainers Association members.

PARTICIPANTS

A total of 304 athletic trainers.

DATA COLLECTION AND ANALYSIS

Respondents completed a Web-based survey reporting years of experience, competitive level of athletes supervised, satisfaction with asthma education, experience evaluating asthma symptoms, and comfort managing asthma.

RESULTS

Response rate was 13.9% (304 of 2,175). At least 23% of respondents evaluated asthma symptoms five or more times the previous year. Respondents working exclusively with junior high and/or high school athletes evaluated asthma symptoms more frequently than those working exclusively with college and/or professional athletes. Fifty-eight percent of respondents were unsatisfied with their asthma education. Only 25.3% were "very" comfortable managing asthma. Respondents with higher comfort levels evaluated asthma symptoms more frequently (p < 0.01, r = 0.18) and were more likely to be satisfied with their asthma education (p < 0.001). Over 95% of respondents endorsed more asthma education in athletic training curricula.

CONCLUSIONS

Results of this pilot study indicate that athletic trainers have opportunities to help athletes manage asthma symptoms that can compromise athletic performance or limit sports participation. However, few athletic trainers are very comfortable managing asthma, and most are unsatisfied with their asthma education. Further study is needed to determine the effect of enhanced asthma education on athletic trainers' comfort and skills with asthma evaluation and management.

Asthma in medium altitude--exercise-induced bronchoconstriction in hypobaric environment in subjects with asthma

BACKGROUND

Hypoxic gas inhalation has been reported to enhance airway responsiveness and results in bronchoconstriction in animal models and in humans with asthma. However, the data have so far been conflicting. The aim of the present study was to examine the effect of reduced barometric pressure on exercise-induced bronchoconstriction (EIB) in subjects with asthma.

METHODS

Twenty subjects (10-45 years old, male symbol/female symbol = 13/7) with asthma (at least 10% reduction in forced expiratory volume in 1-second postexercise) participated in exercise testing in barometric pressure corresponding to altitudes of 200 (normobaric) and 2500 (hypobaric) m above sea level in random order on separate days. Lung function was measured before and after exercise, as well as after inhalation of salbutamol. Heart rate, oxygen uptake (), arterial oxygen saturation (S(p)O(2)), respiratory gas exchange ratio (RER) and minute ventilation () were measured during exercise.

RESULTS

There was no difference in lung function after exercise. The and HR(peak) during exercise did not differ. The RER(peak) was higher (P = 0.04) in hypobaric environment. The decreased 10.1% (7.2-13.0) [mean (95% confidence intervals)] (P < 0.001) from normobaric to hypobaric environment. At the same time, S(p)O(2) at decreased from 94.4 (92.2-96.6) to 85.6% (82.8-88.4) (P < 0.001).

CONCLUSIONS

A barometric pressure corresponding to altitude of 2500 m did not increase EIB in subjects with asthma. The reduction in is most probably due to the lower S(p)O(2) in hypobaric environment.

Respiratory diseases and high altitude

The aim of this paper is to review how preexisting pulmonary diseases can be affected by altitude exposure. Obstructive (asthma and chronic obstructive pulmonary disease or COPD) and restrictive (interstitial pulmonary fibrosis), as well as pulmonary vascular diseases, will be considered, and the goal will be to provide insight and tools to clinicians to optimize the medical condition and thus the life-style of these patients. The underlying pathophysiologies and the effect of hypobaric hypoxia on these diseases will be reviewed such that techniques to assess patients will be appropriate. Therapeutic interventions, including the use of supplemental oxygen, in light of the underlying pathologic processes, will also be discussed.

Exercise-induced bronchoconstriction in children: montelukast attenuates the immediate-phase and late-phase responses

BACKGROUND

Montelukast, a leukotriene receptor antagonist, attenuates exercise-induced bronchoconstriction. We and others have shown that there is a late-phase response 3 to 8 hours after exercise in a subset of asthmatic patients.

OBJECTIVE

We sought to evaluate the protective effect of montelukast on immediate-phase and late-phase responses after exercise challenges.

METHODS

Twenty-two atopic asthmatic children aged 7 to 16 years with reproducible exercise-induced bronchoconstriction (minimum of 15% decrease of FEV(1) from baseline) were enrolled in this placebo-controlled crossover study. Exercise challenges were performed while breathing cold dry air, and FEV(1) measurements were taken up to 480 minutes after exercise. Patients underwent exercise challenges on a screening day and 1 week after placebo treatment. Subsequently, after a week with no treatment, pulmonary function was assessed after breathing dry cold air (control day). Finally, an exercise challenge was carried out after a week of treatment with montelukast.

RESULTS

Reproducible late-phase reactions occurred in 5 of 22 patients, which correlated with the extent of the immediate response (P <.05). After 1 week of treatment with montelukast, a significant decrease of immediate responses was observed. Montelukast treatment compared with placebo was associated with a lower mean maximum decrease of FEV(1) (mean +/- SEM: 17.3% +/- 2.4% and 35.1% +/- 2.6%, respectively), decrease of the area above the curve (267.8% +/- 42.7%/min and 868.0% +/- 103.8%/min, respectively), and shorter time for recovery (6.9 +/- 1.1 minutes and 30.9 +/- 4.0 minutes, respectively; P <.05). Treatment with montelukast also abolished late-phase responses.

CONCLUSION

Once daily treatment with oral montelukast attenuated the immediate-phase response and abolished the late-phase response induced by means of exercise challenge in asthmatic children.

Exercise-induced bronchospasm in the elite athlete

The term exercise-induced bronchospasm (EIB) describes the acute transient airway narrowing that occurs during and most often after exercise in 10 to 50% of elite athletes, depending upon the sport examined. Although multiple factors are unquestionably involved in the EIB response, airway drying caused by a high exercise-ventilation rate is primary in most cases. The severity of this reaction reflects the allergic predisposition of the athlete, the water content of the inspired air, the type and concentration of air pollutants inspired, and the intensity (or ventilation rate) of the exercise. The highest prevalence of EIB is seen in winter-sport populations, where athletes are chronically exposed to cold dry air and/or environmental pollutants found in indoor ice arenas. When airway surface liquid lost during the natural warming and humidification process of respiration is not replenished at a rate equal to the loss, the ensuing osmolarity change stimulates the release of inflammatory mediators and results in bronchospasm; this cascade of events is exacerbated by airway inflammation and airway remodelling. The acute EIB response is characterised by airway smooth muscle contraction, membrane swelling, and/or mucus plug formation. Evidence suggests that histamine, leukotrienes and prostanoids are likely mediators for this response. Although the presence of symptoms and a basic physical examination are marginally effective, objective measures of lung function should be used for accurate and reliable diagnosis of EIB. Diagnosis should include baseline spirometry, followed by an appropriate bronchial provocation test. To date, the best test to confirm EIB may simply be standard pulmonary function testing before and after high-intensity dry air exercise. A 10% post-challenge fall in forced expiratory volume in 1 second is used as diagnostic criteria. The goal of medical intervention is to limit EIB exacerbation and allow the athlete to train and compete symptom free. This is attempted through daily controller medications such as inhaled corticosteroids or by the prophylactic use of medications before exercise. In many cases, EIB is difficult to control. These and other data suggest that EIB in the elite athlete is in contrast with classic asthma.

Exercise-induced bronchospasm prevalence in collegiate cross-country runners

PURPOSE

The purpose of this study was to determine the prevalence of exercise-induced bronchospasm (EIB) in collegiate cross-country runners using a protocol involving an intense exercise challenge conducted in the same environment in which the athletes train and compete.

METHODS

One-hundred eighteen collegiate cross-country runners from the Los Angeles, California, metropolitan area participated in the study. All testing took place on a track at the time and location of a normal practice session. The baseline peak expiratory flow rate (PEFR) measurements (best of three) and preexercise heart rate were recorded, after which the athletes ran 2000 m on a track at 85% of maximum heart rate. The postexercise heart rate was recorded and then PEFR measurements at 2, 5, 10, and 30 min after exercise were recorded. The athletes completed a 16-item questionnaire regarding asthma symptoms and health history. Those athletes with a history of asthma and currently taking medications for the asthma were then excluded from statistical analysis of the questionnaire responses. A decrease in PEFR of 15% was considered positive for EIB.

RESULTS

Of the 114 athletes not currently taking medications for asthma, at least 14% (16 athletes) were EIB positive. There was a poor correlation between reported symptoms of asthma and testing positive for EIB.

CONCLUSION

This study demonstrates a high prevalence of EIB in collegiate cross-country runners (at least 14%) and that reported symptoms are a poor predictor of actual EIB.

Laboratory protocol for exercise asthma to evaluate salbutamol given by two devices

PURPOSE

As new delivery devices and formulations are being introduced for drugs given by inhalation, there is a need to evaluate their equivalence with old preparations. One way to do this is to investigate their equivalence in protecting from exercise-induced asthma (EIA).

METHODS

We used a protocol for EIA to compare the protective effect of salbutamol delivered by the pressurised metered dose inhaler (pMDI) and the new Diskus dry powder device. Twenty-seven asthmatic subjects with moderately severe EIA completed an exercise test on four separate days at two study centers. Exercise was performed by cycling for 8 min while inhaling dry air (0% RH, 20-24 degrees C). The target workload in W was predicted as (53.76 x predicted FEV1) - 11.07 and 95% of this target was achieved at 4 min of exercise. This target was chosen in order to achieve ventilation between 50 and 60% of predicted maximum in the last 4 min.

RESULTS

There was no significant difference in the workload, ventilation, or heart rate achieved on the study days. The severity of EIA was measured as the % fall in FEV1. EIA severity was similar on the placebo and control day and the coefficient of variation was 19.4%. The mean +/- SD % fall on the control, placebo, salbutamol by Diskus, and pMDI were 42.0% +/- 15, 39.4% +/-17.6, 13.4% +/- 13.2, and 8.5% +/- 13.8, respectively. Salbutamol significantly inhibited the % fall in FEV1 after exercise, and there was no difference between the preparations.

CONCLUSION

The protocol described here is suitable for evaluating equivalence of salbutamol preparations in protecting against EIA and could be used to evaluate the protective effect of other medications.

Exercise-induced bronchoconstriction depends on exercise load

Exercise-induced bronchoconstriction (EIB) is often used as a measure of bronchial hyperresponsiveness and employed in epidemiological studies. Different tests are used, including free running tests with poor standardization of exercise load. The present study aimed to assess the role of exercise load in relationship to level of EIB.

METHODS

20 asthmatic children, 9-17 years old with a history of EIB, underwent two treadmill test with 85% and 95% exercise load. The children ran with increasing speed for the first 2 min until reaching a heart rate of 85% or 95% of calculated maximum (220-age) and maintained this speed for the last 4 min. Lung function was measured before running, and 0, 3, 6, 10 and 15 min after the run. Borg scale for perceived exertion was employed for children's self-evaluation of exercise load.

RESULTS

Peak heart rate, mean Borg score during 85% exercise load was 178.7/13.6 and during 95% was 194.3/18.2 (P<0.001). Maximum fall in FEV1 after 85% exercise load was 8.84% vs. 25.11% after 95% (P<0.001). Nine subjects (40%) fell > or = 10% in FEV1 after 85% exercise load vs. 20 subjects (100%) after 95% exercise load. EIB from the 95% exercise load test had markedly higher correlation with serum ECP (r=0.77, P<0.001).

CONCLUSION

Exercise load is essential for the interpretation of EIB, and strict standardization of exercise tests should be undertaken. The EIB from the high exercise load tests seemed better correlated to inflammatory activity than the low exercise load test.

Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge

PURPOSE

The purpose of this study was to compare a laboratory based exercise challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function test (PFT) exercise-induced asthma (EIA) screening of elite athletes.

METHODS

Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA (FBC screened) served as subjects. Twenty-three gender and sport matched controls (nonasthmatics) were randomly selected to establish PFT reference values for normal elite athletes. Before FBC, athletes completed a medical history questionnaire for EIA symptoms. FBC evaluations consisted of baseline spirometry, actual or simulated competition, and 5, 10, and 15 min postexercise spirometry. PFT positive athletes were evaluated in the laboratory using an exercise challenge simulating race intensity (ambient conditions: 21 degrees C, 60% relative humidity). PFT procedures were identical to FBC.

RESULTS

91% of PFT positive and 48% of PFT normal athletes reported at least one symptom of EIA, with postrace cough most frequent. Baseline spirometry was the same for PFT positives and normal controls. Lower limit reference range (MN - 2 SD) of FEV1 for controls suggests that postexercise decrements of greater than approximately -7% indicate abnormal airway response in this population. Exercise time duration did not effect bronchial reactivity; 78% of FBC PFT positives were PFT normal post-LBC.

CONCLUSION

Self-reported symptoms by elite athletes are not reliable in identifying EIA. Reference range criterion for FEV1 decrement in the elite athlete postexercise contrasts current recommended guidelines. Moreover, a large number of false negatives may occur in this population if EIA screening is performed with inadequate exercise and environmental stress.

Cold air inhalation and exercise-induced bronchoconstriction in relationship to metacholine bronchial responsiveness: different patterns in asthmatic children and children with other chronic lung diseases

Cold air inhalation and exercise-induced bronchoconstriction (EIB) have both been used as measures of bronchial responsiveness. Both stimuli are often combined in the Nordic climate. The main objective of the present study was to investigate the climatic influence of cold temperatures upon exercise-induced asthma. The secondary aims were: (a) to assess metacholine bronchial hyper-responsiveness and EIB in children with bronchial asthma (n = 32; mean age 10.8 years) compared to children with other chronic lung diseases (CLD) (n = 26, mean age 10.1 years); and (b) to assess the influence of cold air inhalation upon EIB in the two groups of children. Methods used were: (a) the metacholine concentration causing a reduction in FEV1 of 20% (PC20-M), (b) maximum FEV1 fall (delta FEV1) after submaximal treadmill run (EIB test); and (c) delta FEV1 after submaximal treadmill run while inhaling cold (-20 degrees C) dry air (CA-EIB test). Geometric mean PC20-M did not differ significantly between the asthma children (1.28 mg ml-1) and the CLD children (2.90 mg ml-1). In the asthma children, mean delta FEV1 after EIB test was 12.8% vs 21.8% after adding cold air (P < 0.0001), compared to 5.2 and 7.4%, respectively (P = 0.03), in the CLD group. Maximum sensitivity and specificity for the EIB test were 69.8% at a fall in FEV1 of 6.8%; for the CA-EIB test, 72% at a fall in FEV1 of 10.2%; and for metacholine provocation, 56% at a PC20-M of 1.5 mg ml-1. In conclusion, children with bronchial asthma are substantially more sensitive to cold air than children with CLD, and EIB is markedly increased by cold air inhalation in asthmatic children, maintaining the specificity of the EIB test and increasing the sensitivity. The low sensitivity of the EIB test is probably influenced by the use of inhaled steroids. Metacholine inhalation test has less specificity and sensitivity in discriminating asthma from other chronic lung diseases.

Clinical features predictive of exercise-induced asthma in children

Exercise-induced asthma (EIA) is a common symptom among young asthmatics. The hypothesis that asymptomatic day-to-day wide fluctuations in lung function and asymptomatic persistent airflow obstruction are risk factors for the development of EIA was studied. The study population was a cohort of known asthmatic children aged 9-14 years attending a residential asthma camp. The method involved the observation of baseline expiratory peak flow recordings (PEFR) for 5 days while the children were receiving their usual maintenance therapy. The method also included the determination of FEV1 pre- and post- 15 min of continuous aerobic exercise. Exercise-induced asthma was expressed as the Lability index (LI). The findings were that LI was significantly correlated (P < 0.01) with the mean PEFR as a per cent of each child's predicted PEFR. The lability index also correlated (P < 0.01) with the degree of day-to-day variability in PEFR expressed as the coefficient of variance (CV). It is concluded that there is a significant correlation between baseline asthma control and the development of EIA. In addition to recommending pre-exercise prophylaxis, practitioners should investigate overall asthma control in children reporting EIA.

The incidence of exercise-induced bronchospasm in competitive figure skaters

Pediatric commitment to competitive sports is on the rise. Previous reports of the incidence of exercise-induced bronchospasm (EIB) have investigated high school, college, and Olympic athletes in traditional sports. The purpose of this study was to investigate the incidence of EIB in competitive figure skating, a high-intensity, cold-weather sport performed by young athletes. To investigate the incidence of EIB in skaters, 100 competitive skaters from five Mid-Atlantic rinks completed rinkside pulmonary function tests. Results showed an overall incidence of 30%, signaling the need for education and screening for EIB in youth participating in physically demanding, cold-weather sports.

Exercise- and cold-induced asthma

Exercise- and cold-induced asthma are commonly recognized respiratory disorders. The asthmatic response includes several factors contributing to airway narrowing, and thus increased airway resistance. These include airway smooth muscle contraction, mucus accumulation, and bronchial vascular congestion as well as epithelial damage and vascular leakage. The etiology for these disorders is nonantigenic. The primary stimulus is probably a combination of airway cooling and drying (leading to hypertonicity of airway lining fluid). Symptoms generally do not occur during the stimulus period (e.g., exercise) itself. This protection may in part be due to increased catecholamine levels during exercise. The early phase response, which occurs 5 to 15 min poststimulus, may be mediated through a combination of (a) direct influences, (b) vagal reflexes triggered by airway sensory receptors, or (c) responses to mediator release. Spontaneous recovery occurs within 30 min to 2 hrs. There is usually a refractory period of about 1 to 2 hrs during which responses to further stimuli are attenuated. This may be due to depletion of histamine and other mediators. As well, prostaglandin release (mediated via LTD4 which is released during exercise) inhibits further airway narrowing. A late phase response has been reported 4 to 10 hrs poststimulus in some patients. These reactions are accompanied by a second release of histamine and other mediators that cause inflammatory responses and epithelial damage. However, the exercise dependence of this response is debated.

A mask to modify inspired air temperature and humidity and its effect on exercise induced asthma

BACKGROUND

Heat and moisture loss from the respiratory tract during exercise are important triggers of exercise induced asthma.

METHODS

A new heat and moisture exchange mask has been developed which both recovers exhaled heat and water and has a sufficiently low resistance for use during exercise. The effect of the mask on inspired air temperature was studied in four normal subjects. Eight asthmatic subjects performed identical exercise protocols on three separate days, breathing room air through a conventional mouthpiece, a dummy mask, and the new heat and moisture exchange mask. Seven different asthmatic subjects exercised while breathing cold air at -13 degrees C through a dummy or active mask.

RESULTS

All subjects found the new mask comfortable to wear. The mean inspired temperature when the mask was used rose to 32.5 (1.4) degrees C when normal subjects breathed room air at 24 degrees C and to 19.1 (2.7) degrees C when they inhaled subfreezing air at -13 degrees C. The heat and moisture exchange mask significantly reduced the median fall in forced expiratory volume in one second (FEV1) after exercise to 13% (range 0-49%) when asthmatic subjects breathed room air compared with 33% (10-65%) with the dummy mask and 28% (21-70%) with the mouthpiece. The fall in FEV1 when the asthmatic subjects breathed cold air was 10% (0-26%) with the heat and moisture exchange mask compared with 22% (13-51%) with the dummy mask.

CONCLUSION

Use of a heat and moisture exchange mask can raise the inspired temperature and humidity and ameliorate the severity of exercise induced asthma. The mask may be of practical value in non-contact sport or for people working in subzero temperatures.

Effect of cetirizine on exercise induced asthma

The effect of oral and inhaled cetirizine, a potent and specific H1 receptor antagonist, was studied in patients with exercise induced asthma. Twelve patients (five male; mean age 35.2 years) were given oral placebo or cetirizine 10 mg twice daily for one week, double blind and in randomised order, and exercised on a treadmill for six to eight minutes at a submaximal work load two hours after the final dose. There was no significant change in baseline FEV1 after treatment and cetirizine failed to inhibit exercise induced bronchoconstriction (maximum falls in FEV1 28% and 27% of baseline). In a further eight patients (four male; mean age 40.8 years) the effect of 1 ml cetirizine (5 and 10 mg/ml) given through a Wright nebuliser was compared with that of placebo in a double blind trial. The fall in FEV1 after exercise was reduced after both concentrations of cetirizine by 15.2% of baseline after 5 mg/ml and by 10.2% after 10 mg/ml, compared with 23.7% after placebo. In two patients cetirizine had no effect. In a further study cetirizine (10 mg/ml) given by inhalation displaced the geometric mean PC20 histamine 13.1 fold to the right by comparison with placebo. The reason for the difference between the effects of oral and of inhaled cetirizine on exercise asthma is not clear but may be related to differences in local concentration in the airway.

Sports-Aggravated Allergies

In brief Many people suffer from asthma MH and other allergic conditions. Participating in sports exposes these people both to specific allergens and to nonspecific factors that will influence the presentation of their allergic symptoms. Allergy patients experience both beneficial and deleterious effects of sports participation. For the patient whose symptoms are triggered or aggravated by sports activity, treatment should focus on avoiding or modifying the triggering factors either through physical means or through the use of pharmacologic agents.

Effect of submaximal exercise at low temperatures on pulmonary function in healthy young men

In order to understand more fully the effect on pulmonary function of whole body exposure to cold during submaximal exercise, we measured pulmonary function indices in ten healthy male students and ten healthy male forestry workers of similar age following submaximal treadmill walking at different temperatures in a climatic chamber. After measuring the maximal aerobic capacity with a cycle ergometer test, the subjects had to walk on four separate occasions in the climatic chamber at an intensity of 70%-75% of their individual maximal heart rate; the first at normal room temperature and then randomly, either at 0 degrees C or at -20 degrees C, and vice versa. The duration of each walk was 8 min. Finally, each subject had to walk in the chamber at -20 degrees C for 17 min. Flow volume spirometry was performed at room temperature 1, 5, 10, and 20 min after exercise and the values were compared to baseline values taken prior to the last walking test. There were only minor changes in pulmonary function indices following exercise at different temperatures. Only one student showed a reduction of over 15% in peak expiratory flow rate after an 8-min walk at -20 degrees C. It seems that submaximal exercise of short duration, even at a temperature as low as -20 degrees C, does not impair pulmonary function in healthy young men.

Inhaled lignocaine does not alter bronchial hyperresponsiveness to hyperventilation of dry cold air in asthmatic subjects

It has been hypothesized that bronchoconstriction due to exercise and hyperventilation is caused by the stimulation of irritant receptors in the upper airways. However, controversial results have been reported on the effect of lignocaine, which can inhibit the stimulation of these receptors. The aim of this study was to investigate the effect of inhaled lignocaine on bronchial responsiveness to hyperventilation of cold dry air in asthmatic subjects. Eight adult asthmatic subjects in a clinical steady state came on four different days (two placebo and two active days in random order) with a maximum interval of 3 weeks. After assessment of forced expiratory flow rates, inhalation of either phosphate-buffered saline (placebo) or lignocaine solution (40 mg) was carried out in a single-blind fashion. The technician was not aware which medication was being inhaled, but the asthmatic subject knew which drug it was by the sensation in his or her throat. Forced expiratory flow rates were reassessed 15 min after the nebulization; then, the subjects were asked to inhale cold dry air (-20 degrees C) in progressively increasing levels of ventilation (7.5, 15, 30 and 60 l/min and maximum voluntary ventilation). PD20 was interpolated from the dose-response curve, relating the dose of cold air on a non-cumulative logarithmic scale on the abscissa and the percentage change in FEV1 on the ordinate. There were no significant changes in FEV1 and PD20 after inhalation of lignocaine as compared to the placebo. We conclude that inhaled lignocaine does not significantly alter bronchial hyperresponsiveness to hyperventilation of cold air in asthmatic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)