Jon Ayres | University of Birmingham (original) (raw)

Papers by Jon Ayres

Occupational and Environmental Medicine, 2009

To investigate preclinical adverse effects of ambient particulate air pollution and nitrogen oxid... more To investigate preclinical adverse effects of ambient particulate air pollution and nitrogen oxides in patients with heart failure. A cohort of 132 non-smoking patients living in Aberdeen, Scotland, with stable chronic heart failure were enrolled in a repeated-measures panel study. Patients with atrial fibrillation or pacemakers were excluded. Participants were studied for 3 days every 2 months for up to 1 year with monitoring of pollutant exposure and concurrent measurements of pathophysiological responses. Measurements included daily area concentration of particulate matter with a median aerodynamic diameter of <10 micrometres (PM(10)), particle number concentration (PNC) and nitrogen oxides; daily estimated personal concentration of particulate matter with a median aerodynamic diameter of <2.5 micrometres (PM(2.5)) and PNC exposures; and 3-day cumulative personal nitrogen dioxide (NO(2)). Concurrent meteorological data were recorded. Blood was taken at the end of each 3-day block for assays of markers of endothelial activation, inflammation and coagulation. Cardiac rhythm was monitored by ambulatory Holter monitor during the final 24 h of each block. The average 24 h background ambient PM(10) ranged from 7.4 to 68 microg.m(-3) and PNC from 454 to 11 283 particles.cm(-3). No associations were demonstrated between the incidence of arrhythmias, heart rate variability or haematological/biochemical measures and any variations in pollutant exposures at any lags. Assuming that low-level pollution affects the parameters measured, these findings may suggest a beneficial effect of modern cardioprotective therapy, which may modify responses to external risk factors. Widespread use of such drugs in susceptible populations may in future reduce the adverse effects of air pollution on the heart.

Environmental Science and Pollution Research, 2011

The concentrations of PM(10) mass, PM(2.5) mass and particle number were continuously measured fo... more The concentrations of PM(10) mass, PM(2.5) mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter. Daily PM(10) and PM(2.5) samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 μg. Pre- and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters. The 18-month mean PM(10) and PM(2.5) mass concentrations ranged from 15.4 μg/m(3) in Helsinki to 56.7 μg/m(3) in Athens and from 9.0 μg/m(3) in Helsinki to 25.0 μg/m(3) in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm(3) in Helsinki to 24,180 part/cm(3) in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM(10) with the exception of Athens where PM(2.5) comprised 43% of PM(10). Higher PM mass and number concentrations were measured in winter as compared to summer in all urban areas at a significance level p < 0.05. Significant quantitative and qualitative differences for particle mass across the four urban areas in Europe were observed. These were due to strong local and regional characteristics of particulate pollution sources which contribute to the heterogeneity of health responses. In addition, these findings also bear on the ability of different countries to comply with existing directives and the effectiveness of mitigation policies.

Occupational Hygiene, 2005

Asthma in the Workplace, Third Edition, 2006

About Us; Mobile; Help; Advertise; Links. Shibboleth; Athens; Register; Username: Password. Home;... more About Us; Mobile; Help; Advertise; Links. Shibboleth; Athens; Register; Username: Password. Home; Journals: View All Journals; Expert Opinion on: Biological Therapy; Drug Delivery; Drug Discovery; Drug Metabolism and Toxicology; Drug Safety; ...

Environmental Health Perspectives, 1989

The Weekly Returns System of the Royal College of General Practitioners was used to assess the ef... more The Weekly Returns System of the Royal College of General Practitioners was used to assess the effect on respiratory illness of the acid transport event that occurred during January 1985. The pollution event, as assessed by SO2 and smoke levels measured at pollution monitoring stations within and without the affected area showed only modest rises in SO2 levels, which were less than levels that occurred 4 years earlier. January is the peak time of year for reporting of acute respiratory episodes, and the minor increase in pollution was not reflected in any rise in respiratory morbidity, both for all ages and for different age bands. There was a rise in rates for children up to the age of 14, but this was seen each year and in both polluted and nonpolluted areas. This was probably due to children returning to school after the winter vacation and the subsequent spread of viral infections. The limitations of the two data sets in this analysis are discussed, including the relative insensitivity of weekly data in picking out a short-lived event, the distribution of the practices and pollution monitoring stations, and the effect of the extreme cold weather and the coal miners' strike on domestic coal burning during this event.

Pediatric pulmonology, Jan 15, 2015

Asthma affects children's quality of life (QoL) but factors associated with QoL are not well ... more Asthma affects children's quality of life (QoL) but factors associated with QoL are not well understood. Our hypothesis was that there are factors linked to QoL which are amenable to treatment or environmental modification. QoL was ascertained in a study designed to link environmental exposures to asthma outcomes. Univariate and multivariate analysis were used to determine which factors are associated with QoL. There were 553 children with asthma where QoL was determined, mean age 10.3 and 312 (58%) were boys. The median QoL score was 5.9 (interquartile range 4.6, 6.8). In the multivariate model, asthma severity (as evidenced by British Thoracic Society, BTS, treatment step), smoking exposure, socioeconomic status and rhinitis were associated with the QoL score. QoL score was reduced by (i) 30% [95% confidence interval 20, 39] for those on BTS step 4 compared to BTS step 1 treatment (ii) 11% [2, 19] for children with ≥ two resident smokers with reference to no resident smokers (...

Issues in Environmental Science and Technology, 2007

Patient education and …, Jan 1, 2002

Chronic obstructive pulmonary disease (COPD) is irreversible and causes a progressive reduction i... more Chronic obstructive pulmonary disease (COPD) is irreversible and causes a progressive reduction in physical functioning. There is evidence that emotional distress contributes to loss of function and that improvements may be obtained via psychologically based interventions to alleviate anxiety and panic. This systematic review examined the most effective interventions to date. A literature search revealed 25 studies; these were assessed using standardised criteria for inclusion and quality. Six randomised, controlled trials fulfilled the criteria, but the variety of methods, interventions and measures prevented the use of a meta-analysis. Two studies were unpublished doctoral theses, four were published studies. All of the studies had one or more deficiencies; failure to measure or report lung function, large variation in attrition, lack of blinding in assessment of treatment outcome, lack of use of standardised anxiety measures. Description of the intervention was not always sufficient to allow replication. There were no trials of interventions aimed at reducing panic. No study was adequately designed to provide an assessment of psychological intervention aimed at anxiety in COPD. Secondary outcomes included impacts on breathlessness, disability and quality of life. It can be concluded that currently there is insufficient research of quality on which to base recommendations for effective interventions for anxiety and panic in COPD. Future research should tie the design of evaluation to interventions based on theories of the relationship between dyspnoea and anxiety.

Annals of Occupational Hygiene, 2010

Evaluate the effect of smoke-free legislation on fine particulate [particulate matter &am... more Evaluate the effect of smoke-free legislation on fine particulate [particulate matter <2.5 microm in diameter (PM(2.5))] air pollution levels in bars in Scotland, England, and Wales. Air quality was measured in 106 randomly selected bars in Scotland, England, and Wales before and after the introduction of smoking restrictions. PM(2.5) concentrations were measured covertly for 30-min periods before smoke-free legislation was introduced, again at 1-2 months post-ban (except Wales) and then at 12-months post-baseline (except Scotland). In Scotland and England, overt measurements were carried out to assess bar workers' full-shift personal exposures to PM(2.5). Postcode data were used to determine socio-economic status of the bar location. PM(2.5) levels prior to smoke-free legislation were highest in Scotland (median 197 microg m(-3)), followed by Wales (median 184 microg m(-3)) and England (median 92 microg m(-3)). All three countries experienced a substantial reduction in PM(2.5) concentrations following the introduction of the legislation with the median reduction ranging from 84 to 93%. Personal exposure reductions were also within this range. There was evidence that bars located in more deprived postcodes had higher PM(2.5) levels prior to the legislation. Prior to legislation PM(2.5) concentrations within bars across the UK were much higher than the 65 microg m(-3) 'unhealthy' threshold for outdoor air quality as set by the US Environmental Protection Agency. Concentrations in Scottish and Welsh bars were, on average, two or more times greater than in English bars for which seasonal influences may be responsible. Legislation in all three countries produced improvements in indoor air quality that are consistent with other international studies.

Occupational Medicine, 2014

The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. Schoo... more The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. School teachers routinely use their voices intensively at work and are therefore at a higher risk of dysphonia. To determine the prevalence of voice disorders among primary school teachers in Lagos, Nigeria, and to explore associated risk factors. Teaching and non-teaching staff from 19 public and private primary schools completed a self-administered questionnaire to obtain information on personal lifestyles, work experience and environment, and voice disorder symptoms. Dysphonia was defined as the presence of at least one of the following: hoarseness, repetitive throat clearing, tired voice or straining to speak. A total of 341 teaching and 155 non-teaching staff participated. The prevalence of dysphonia in teachers was 42% compared with 18% in non-teaching staff. A significantly higher proportion of the teachers reported that voice symptoms had affected their ability to communicate effectively. School type (public/private) did not predict the presence of dysphonia. Statistically significant associations were found for regular caffeinated drink intake (odds ratio [OR] = 3.07; 95% confidence interval [CI]: 1.51-6.62), frequent upper respiratory tract infection (OR = 3.60; 95% CI: 1.39-9.33) and raised voice while teaching (OR = 10.1; 95% CI: 5.07-20.2). Nigerian primary school teachers were at risk for dysphonia. Important environment and personal factors were upper respiratory infection, the need to frequently raise the voice when teaching and regular intake of caffeinated drinks. Dysphonia was not associated with age or years of teaching.

QJM, 2013

Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases f... more Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following the occurrence of thunderstorms in the local vicinity. The roles of accompanying meteorological features and aeroallergens, such as pollen grains and fungal spores, have been studied in an effort to explain why thunderstorm asthma does not accompany all thunderstorms. Despite published evidence being limited and highly variable in quality due to thunderstorm asthma being a rare event, this article reviews this evidence in relation to the role of aeroallergens, meteorological features and the impact of thunderstorm asthma on health services. This review has found that several thunderstorm asthma events have had significant impacts on individuals' health and health services with a range of different aeroallergens identified. This review also makes recommendations for future public health advice relating to thunderstorm asthma on the basis of this identified evidence.

Environmental Research, 2008

Bmc Public Health, May 2, 2012

Journal of the Royal Society of Medicine, Mar 1, 2001

Thorax, 1999

Steroid resistant asthma (SRA) represents a small subgroup of those patients who have asthma and ... more Steroid resistant asthma (SRA) represents a small subgroup of those patients who have asthma and who are difficult to manage. Two patients with apparent SRA are described, and 12 additional cases who were admitted to the same hospital are reviewed. The subjects were selected from a tertiary hospital setting by review of all asthma patients admitted over a two year period. Subjects were defined as those who failed to respond to high doses of bronchodilators and oral glucocorticosteroids, as judged by subjective assessment, audible wheeze on examination, and serial peak flow measurements. In 11 of the 14 patients identified there was little to substantiate the diagnosis of severe or steroid resistant asthma apart from symptoms and upper respiratory wheeze. Useful tests to differentiate this group of patients from those with severe asthma appear to be: the inability to perform reproducible forced expiratory manoeuvres, normal airway resistance, and a concentration of histamine causing a 20% fall in the forced expiratory volume (FEV1) being within the range for normal subjects (PC20). Of the 14 subjects, four were health care staff and two reported childhood sexual abuse. Such patients are important to identify as they require supportive treatment which should not consist of high doses of glucocorticosteroids and beta2 adrenergic agonists. Diagnoses other than asthma, such as gastro-oesophageal reflux, hyperventilation, vocal cord dysfunction and sleep apnoea, should be sought as these may be a cause of glucocorticosteroid treatment failure and pseudo-SRA, and may respond to alternative treatment.

Ascent to altitude poses immense challenges on human body, including exposure to extremely low te... more Ascent to altitude poses immense challenges on human body, including exposure to extremely low temperatures, low atmospheric pressures and hypoxia, which may lead to specific altitude related illnesses such as Acute Mountain Sickness (AMS), High Altitude ...

Occupational and Environmental Medicine, 2009

To investigate preclinical adverse effects of ambient particulate air pollution and nitrogen oxid... more To investigate preclinical adverse effects of ambient particulate air pollution and nitrogen oxides in patients with heart failure. A cohort of 132 non-smoking patients living in Aberdeen, Scotland, with stable chronic heart failure were enrolled in a repeated-measures panel study. Patients with atrial fibrillation or pacemakers were excluded. Participants were studied for 3 days every 2 months for up to 1 year with monitoring of pollutant exposure and concurrent measurements of pathophysiological responses. Measurements included daily area concentration of particulate matter with a median aerodynamic diameter of <10 micrometres (PM(10)), particle number concentration (PNC) and nitrogen oxides; daily estimated personal concentration of particulate matter with a median aerodynamic diameter of <2.5 micrometres (PM(2.5)) and PNC exposures; and 3-day cumulative personal nitrogen dioxide (NO(2)). Concurrent meteorological data were recorded. Blood was taken at the end of each 3-day block for assays of markers of endothelial activation, inflammation and coagulation. Cardiac rhythm was monitored by ambulatory Holter monitor during the final 24 h of each block. The average 24 h background ambient PM(10) ranged from 7.4 to 68 microg.m(-3) and PNC from 454 to 11 283 particles.cm(-3). No associations were demonstrated between the incidence of arrhythmias, heart rate variability or haematological/biochemical measures and any variations in pollutant exposures at any lags. Assuming that low-level pollution affects the parameters measured, these findings may suggest a beneficial effect of modern cardioprotective therapy, which may modify responses to external risk factors. Widespread use of such drugs in susceptible populations may in future reduce the adverse effects of air pollution on the heart.

Environmental Science and Pollution Research, 2011

The concentrations of PM(10) mass, PM(2.5) mass and particle number were continuously measured fo... more The concentrations of PM(10) mass, PM(2.5) mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter. Daily PM(10) and PM(2.5) samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 μg. Pre- and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters. The 18-month mean PM(10) and PM(2.5) mass concentrations ranged from 15.4 μg/m(3) in Helsinki to 56.7 μg/m(3) in Athens and from 9.0 μg/m(3) in Helsinki to 25.0 μg/m(3) in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm(3) in Helsinki to 24,180 part/cm(3) in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM(10) with the exception of Athens where PM(2.5) comprised 43% of PM(10). Higher PM mass and number concentrations were measured in winter as compared to summer in all urban areas at a significance level p < 0.05. Significant quantitative and qualitative differences for particle mass across the four urban areas in Europe were observed. These were due to strong local and regional characteristics of particulate pollution sources which contribute to the heterogeneity of health responses. In addition, these findings also bear on the ability of different countries to comply with existing directives and the effectiveness of mitigation policies.

Occupational Hygiene, 2005

Asthma in the Workplace, Third Edition, 2006

About Us; Mobile; Help; Advertise; Links. Shibboleth; Athens; Register; Username: Password. Home;... more About Us; Mobile; Help; Advertise; Links. Shibboleth; Athens; Register; Username: Password. Home; Journals: View All Journals; Expert Opinion on: Biological Therapy; Drug Delivery; Drug Discovery; Drug Metabolism and Toxicology; Drug Safety; ...

Environmental Health Perspectives, 1989

The Weekly Returns System of the Royal College of General Practitioners was used to assess the ef... more The Weekly Returns System of the Royal College of General Practitioners was used to assess the effect on respiratory illness of the acid transport event that occurred during January 1985. The pollution event, as assessed by SO2 and smoke levels measured at pollution monitoring stations within and without the affected area showed only modest rises in SO2 levels, which were less than levels that occurred 4 years earlier. January is the peak time of year for reporting of acute respiratory episodes, and the minor increase in pollution was not reflected in any rise in respiratory morbidity, both for all ages and for different age bands. There was a rise in rates for children up to the age of 14, but this was seen each year and in both polluted and nonpolluted areas. This was probably due to children returning to school after the winter vacation and the subsequent spread of viral infections. The limitations of the two data sets in this analysis are discussed, including the relative insensitivity of weekly data in picking out a short-lived event, the distribution of the practices and pollution monitoring stations, and the effect of the extreme cold weather and the coal miners' strike on domestic coal burning during this event.

Pediatric pulmonology, Jan 15, 2015

Asthma affects children's quality of life (QoL) but factors associated with QoL are not well ... more Asthma affects children's quality of life (QoL) but factors associated with QoL are not well understood. Our hypothesis was that there are factors linked to QoL which are amenable to treatment or environmental modification. QoL was ascertained in a study designed to link environmental exposures to asthma outcomes. Univariate and multivariate analysis were used to determine which factors are associated with QoL. There were 553 children with asthma where QoL was determined, mean age 10.3 and 312 (58%) were boys. The median QoL score was 5.9 (interquartile range 4.6, 6.8). In the multivariate model, asthma severity (as evidenced by British Thoracic Society, BTS, treatment step), smoking exposure, socioeconomic status and rhinitis were associated with the QoL score. QoL score was reduced by (i) 30% [95% confidence interval 20, 39] for those on BTS step 4 compared to BTS step 1 treatment (ii) 11% [2, 19] for children with ≥ two resident smokers with reference to no resident smokers (...

Issues in Environmental Science and Technology, 2007

Patient education and …, Jan 1, 2002

Chronic obstructive pulmonary disease (COPD) is irreversible and causes a progressive reduction i... more Chronic obstructive pulmonary disease (COPD) is irreversible and causes a progressive reduction in physical functioning. There is evidence that emotional distress contributes to loss of function and that improvements may be obtained via psychologically based interventions to alleviate anxiety and panic. This systematic review examined the most effective interventions to date. A literature search revealed 25 studies; these were assessed using standardised criteria for inclusion and quality. Six randomised, controlled trials fulfilled the criteria, but the variety of methods, interventions and measures prevented the use of a meta-analysis. Two studies were unpublished doctoral theses, four were published studies. All of the studies had one or more deficiencies; failure to measure or report lung function, large variation in attrition, lack of blinding in assessment of treatment outcome, lack of use of standardised anxiety measures. Description of the intervention was not always sufficient to allow replication. There were no trials of interventions aimed at reducing panic. No study was adequately designed to provide an assessment of psychological intervention aimed at anxiety in COPD. Secondary outcomes included impacts on breathlessness, disability and quality of life. It can be concluded that currently there is insufficient research of quality on which to base recommendations for effective interventions for anxiety and panic in COPD. Future research should tie the design of evaluation to interventions based on theories of the relationship between dyspnoea and anxiety.

Annals of Occupational Hygiene, 2010

Evaluate the effect of smoke-free legislation on fine particulate [particulate matter &am... more Evaluate the effect of smoke-free legislation on fine particulate [particulate matter <2.5 microm in diameter (PM(2.5))] air pollution levels in bars in Scotland, England, and Wales. Air quality was measured in 106 randomly selected bars in Scotland, England, and Wales before and after the introduction of smoking restrictions. PM(2.5) concentrations were measured covertly for 30-min periods before smoke-free legislation was introduced, again at 1-2 months post-ban (except Wales) and then at 12-months post-baseline (except Scotland). In Scotland and England, overt measurements were carried out to assess bar workers' full-shift personal exposures to PM(2.5). Postcode data were used to determine socio-economic status of the bar location. PM(2.5) levels prior to smoke-free legislation were highest in Scotland (median 197 microg m(-3)), followed by Wales (median 184 microg m(-3)) and England (median 92 microg m(-3)). All three countries experienced a substantial reduction in PM(2.5) concentrations following the introduction of the legislation with the median reduction ranging from 84 to 93%. Personal exposure reductions were also within this range. There was evidence that bars located in more deprived postcodes had higher PM(2.5) levels prior to the legislation. Prior to legislation PM(2.5) concentrations within bars across the UK were much higher than the 65 microg m(-3) 'unhealthy' threshold for outdoor air quality as set by the US Environmental Protection Agency. Concentrations in Scottish and Welsh bars were, on average, two or more times greater than in English bars for which seasonal influences may be responsible. Legislation in all three countries produced improvements in indoor air quality that are consistent with other international studies.

Occupational Medicine, 2014

The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. Schoo... more The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. School teachers routinely use their voices intensively at work and are therefore at a higher risk of dysphonia. To determine the prevalence of voice disorders among primary school teachers in Lagos, Nigeria, and to explore associated risk factors. Teaching and non-teaching staff from 19 public and private primary schools completed a self-administered questionnaire to obtain information on personal lifestyles, work experience and environment, and voice disorder symptoms. Dysphonia was defined as the presence of at least one of the following: hoarseness, repetitive throat clearing, tired voice or straining to speak. A total of 341 teaching and 155 non-teaching staff participated. The prevalence of dysphonia in teachers was 42% compared with 18% in non-teaching staff. A significantly higher proportion of the teachers reported that voice symptoms had affected their ability to communicate effectively. School type (public/private) did not predict the presence of dysphonia. Statistically significant associations were found for regular caffeinated drink intake (odds ratio [OR] = 3.07; 95% confidence interval [CI]: 1.51-6.62), frequent upper respiratory tract infection (OR = 3.60; 95% CI: 1.39-9.33) and raised voice while teaching (OR = 10.1; 95% CI: 5.07-20.2). Nigerian primary school teachers were at risk for dysphonia. Important environment and personal factors were upper respiratory infection, the need to frequently raise the voice when teaching and regular intake of caffeinated drinks. Dysphonia was not associated with age or years of teaching.

QJM, 2013

Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases f... more Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following the occurrence of thunderstorms in the local vicinity. The roles of accompanying meteorological features and aeroallergens, such as pollen grains and fungal spores, have been studied in an effort to explain why thunderstorm asthma does not accompany all thunderstorms. Despite published evidence being limited and highly variable in quality due to thunderstorm asthma being a rare event, this article reviews this evidence in relation to the role of aeroallergens, meteorological features and the impact of thunderstorm asthma on health services. This review has found that several thunderstorm asthma events have had significant impacts on individuals' health and health services with a range of different aeroallergens identified. This review also makes recommendations for future public health advice relating to thunderstorm asthma on the basis of this identified evidence.

Environmental Research, 2008

Bmc Public Health, May 2, 2012

Journal of the Royal Society of Medicine, Mar 1, 2001

Thorax, 1999

Steroid resistant asthma (SRA) represents a small subgroup of those patients who have asthma and ... more Steroid resistant asthma (SRA) represents a small subgroup of those patients who have asthma and who are difficult to manage. Two patients with apparent SRA are described, and 12 additional cases who were admitted to the same hospital are reviewed. The subjects were selected from a tertiary hospital setting by review of all asthma patients admitted over a two year period. Subjects were defined as those who failed to respond to high doses of bronchodilators and oral glucocorticosteroids, as judged by subjective assessment, audible wheeze on examination, and serial peak flow measurements. In 11 of the 14 patients identified there was little to substantiate the diagnosis of severe or steroid resistant asthma apart from symptoms and upper respiratory wheeze. Useful tests to differentiate this group of patients from those with severe asthma appear to be: the inability to perform reproducible forced expiratory manoeuvres, normal airway resistance, and a concentration of histamine causing a 20% fall in the forced expiratory volume (FEV1) being within the range for normal subjects (PC20). Of the 14 subjects, four were health care staff and two reported childhood sexual abuse. Such patients are important to identify as they require supportive treatment which should not consist of high doses of glucocorticosteroids and beta2 adrenergic agonists. Diagnoses other than asthma, such as gastro-oesophageal reflux, hyperventilation, vocal cord dysfunction and sleep apnoea, should be sought as these may be a cause of glucocorticosteroid treatment failure and pseudo-SRA, and may respond to alternative treatment.

Ascent to altitude poses immense challenges on human body, including exposure to extremely low te... more Ascent to altitude poses immense challenges on human body, including exposure to extremely low temperatures, low atmospheric pressures and hypoxia, which may lead to specific altitude related illnesses such as Acute Mountain Sickness (AMS), High Altitude ...