Asthma Emergency Department Presentations Research Articles

Airborne grass pollen and thunderstorms influence emergency department asthma presentations in a subtropical climate

BackgroundGrass pollen is considered a major outdoor aeroallergen source worldwide. It is proposed as a mechanism for thunderstorm asthma that lightning during thunderstorms promotes electrical rupture of pollen grains that leads to allergic airway inflammation. However, most evidence of associations between grass pollen and asthma comes from temperate regions. The objective of this study was to investigate short-term associations between airborne grass pollen exposure and asthma emergency department presentations in a subtropical population. MethodsEpisode level public hospital presentations for asthma (2016–2020) were extracted for greater Brisbane, Australia, from Queensland Health's Emergency Data Collection. Concentrations of airborne pollen were determined prospectively using a continuous flow volumetric impaction sampler. Daily time series analysis using a generalised additive mixed model were applied to determine associations between airborne grass pollen concentrations, and lightning count data, with asthma presentations. ResultsAirborne grass pollen showed an association with asthma presentations in Brisbane; a significant association was detected from same day exposure to three days lag. Grass pollen exposure increased daily asthma presentations up to 48.5% (95% CI: 12%, 85.9%) in female children. Lightning did not modify the effect of grass pollen on asthma presentations, however a positive association was detected between cloud-to-cloud lightning strikes and asthma presentations (P = 0.048). ConclusionAirborne grass pollen exposure may exacerbate symptoms of asthma requiring urgent medical care of children and adults in a subtropical climate. This knowledge indicates an opportunity for targeted management of respiratory allergic disease to reduce patient and health system burden. For the first time, an influence of lightning on asthma was detected in this context. The outcomes support a need for continued pollen monitoring and surveillance of thunderstorm asthma risk in subtropical regions.

Impact of integrated care coordination on pediatric asthma hospital presentations.

IntroductionFrequent asthma attacks in children result in unscheduled hospital presentations. Patient centered care coordination can reduce asthma hospital presentations. In 2016, The Sydney Children's Hospitals Network launched the Asthma Follow up Integrated Care Initiative with the aim to reduce pediatric asthma emergency department (ED) presentations by 50% through developing and testing an integrated model of care led by care coordinators (CCs).MethodsThe integrated model of care was developed by a multidisciplinary team at Sydney Children's Hospital Randwick (SCH,R) and implemented in two phases: Phase I and Phase II. Children aged 2–16 years who presented ≥4 times to the ED of the SCH,R in the preceding 12 months were enrolled in Phase I and those who had ≥4 ED presentations and ≥1 hospital admissions with asthma attack were enrolled in Phase II. Phase I included a suite of interventions delivered by CCs including encouraging parents/carers to schedule follow-up visits with GP post-discharge, ensuring parents/carers are provided with standard asthma resource pack, offering referrals to asthma education sessions, sending a letter to the child's GP advising of the child's recent hospital presentation and coordinating asthma education webinar for GPs. In addition, in Phase II CCs sent text messages to parents/carers reminding them to follow-up with the child's GP. We compared the change in ED visits and hospital admissions at baseline (6 months pre-enrolment) and at 6-and 12-months post-enrolment in the program.ResultsDuring December 2016-January 2021, 160 children (99 in Phase I and 61 in Phase II) were enrolled. Compared to baseline at 6- and 12-months post-enrolment, the proportion of children requiring ≥1 asthma ED presentations reduced by 43 and 61% in Phase I and 41 and 66% in Phase II. Similarly, the proportion of children requiring ≥1 asthma hospital admissions at 6- and 12-months post-enrolment reduced by 40 and 47% in Phase I and 62 and 69% in Phase II.ConclusionOur results support that care coordinator led integrated model of asthma care which enables integration of acute and primary care services and provides families with asthma resources and education can reduce asthma hospital presentations in children.

Spatiotemporal characteristics of asthma emergency department presentations in diverse geographical and climatic regions, Queensland, Australia.

Sudden acute episodes of asthma exacerbation are often treated by hospital EDs. It is hypothesised that determinants of acute asthma would differ across geographic regions. The objective of the present study was to detail seasonality, trends and spatiotemporal patterns of asthma ED presentations across Queensland (QLD), Australia, a state covering 1.8 million square kilometres, spanning multiple climates. Six years of routinely collected data (2012 to 2017) from 28 major QLD public hospitals were extracted from Queensland Health's Emergency Data Collection. The dataset contained individual, episode-level asthma-like diagnoses of ED presentations. Seasonality and trends of acute asthma were assessed through multiplicative time-series analysis. The study consisted of 2192 days with a total of 65 012 asthma ED presentations in QLD. The 6-year average daily incidence rate was 270 asthma ED presentations per 100 000 population. The highest morbidity of asthma ED presentations occurred during the southern hemisphere winter months. Children showed a higher incidence rate compared to adults with males experiencing a higher incidence compared to females up until the age of 13, after which an inversion was observed persisting through adulthood. Seasonality of asthma ED presentations differed with latitude across QLD. Asthma-related ED presentations exhibit spatiotemporal variation across QLD, which appears to be related to climate. Furthermore, aeroallergens and respiratory viruses may be responsible for asthma ED peaks outside the winter period. Socioeconomic status may influence asthma ED presentation rates between regions. This knowledge can guide ongoing management and assist public health policy response.

Outdoor pollen is a trigger of child and adolescent asthma emergency department presentations: A systematic review and meta-analysis.

In the context of increased asthma exacerbations associated with climatic changes such as thunderstorm asthma, interest in establishing the link between pollen exposure and asthma hospital admissions has intensified. Here, we systematically reviewed and performed a meta-analysis of studies on pollen and emergency department (ED) attendance. A search for studies with appropriate search strategy in MEDLINE, EMBASE, Web of Science and CINAHL was conducted. Each study was assessed for quality and risk of bias. The available evidence was summarized both qualitatively and meta-analysed using random-effects models when moderate heterogeneity was observed. Fourteen studies were included. The pollen taxa investigated differed between studies, allowing meta-analysis only of the effect of grass pollen. A statistically significant increase in the percentage change in the mean number of asthma ED presentations (MPC) (pooled results from 3 studies) was observed for an increase in 10 grass pollen grains per cubic metre of exposure 1.88% (95% CI=0.94%, 2.82%). Time series studies showed positive correlations between pollen concentrations and ED presentations. Age-stratified studies found strongest associations in children aged 5-17years old. Exposure to ambient grass pollen is an important trigger for childhood asthma exacerbations requiring ED attendance. As pollen exposure is increasingly a problem especially in relation to thunderstorm asthma, studies with uniform measures of pollen and similar analytical methods are necessary to fully understand its impact on human health.

MP12: Acute asthma presentations to emergency departments in Alberta: an epidemiological analysis of presentations

Introduction: Asthma is a chronic condition and exacerbations are a common reason for emergency department (ED) presentations across Canada. The objective of this study was to characterize and describe acute asthma presentations over a five-year period. Methods: Administrative health data for Alberta from 2011-2015 was obtained from the National Ambulatory Care Reporting System (NACRS) for all adult (>17 years) acute asthma (ICD-10-CA: J45) ED presentations. All presentations to an Alberta ED with a primary or secondary diagnosis of acute asthma were eligible for inclusion. Presentations with a Canadian Triage and Acuity Scale (CTAS) score of 1 were excluded. Data from NACRS were linked with a provincial diagnostic imaging database. Data are reported as means and standard deviation (SD), medians and interquartile range (IQR) or proportions, as appropriate. Results: From 2011-2015, a total of 51,269 (~10,000/year) acute asthma presentations were made by 34,481 patients (~0.3 presentations per patient per year). The median age was 35 years (IQR: 25, 49 years) and more patients were female (57.2%). Few patients arrived to the ED by ambulance (6.5%) and the most frequent CTAS score was 3 (43.5%). The majority of these patients (77%) had a primary diagnosis of asthma in the ED. Differences were explored between those with a primary asthma diagnosis and those with a secondary diagnosis (e.g., ambulance arrival, length of stay, hospital admission, etc.). Although differences were statistically significant, no clinically relevant differences were identified. Patients with asthma most frequently had a co-diagnosis of acute upper respiratory infection (6.2%); other co-diagnoses included bronchitis (4.7%), pneumonia (3.7%), heart failure (0.18%), pulmonary embolism (0.15%), and pneumothorax (0.03%). For 39.3% of patients, ED management included chest x-ray. The majority of patients were discharged from the ED (92.2%) following a median length of stay of 2.2 hours (IQR: 1.2, 3.8 hours). Conclusion: Acute asthma remains an important ED presentation in Alberta and the absolute frequency of presentations has remained relatively stable over the past five years. Frequency of chest x-ray ordering is high and represents a target for future interventions to reduce ionizing radiation exposure, improve patient flow and reduce healthcare costs.

LO80: Chest radiograph ordering for acute asthma presentations to emergency departments in Alberta: regional, site, and physician level variation

Introduction: Most acute asthma presentations to the emergency department (ED) are uncomplicated and do not require chest radiographs (CXR). Evidence suggests that the proportion of acute asthma patients receiving CXRs in the ED is high and varies substantially within and across sites and studies. This study explored CXR ordering and variation in acute asthma presentations to Alberta’s EDs. Methods: Administrative health data for Alberta was obtained from the National Ambulatory Care Reporting System (NACRS) for all adult (>17 years) acute asthma (ICD-10-CA: J45) ED visits from 2011-2015. Patients with a primary or secondary diagnosis of asthma were included, provided they had a Canadian Triage and Acuity Scale score of 2-5. NACRS data were linked with Alberta Health Services’ (AHS) diagnostic imaging database. Preliminary analysis on variation in imaging at the zone, ED site, and physician level was completed using SAS (v.9.4). Physicians who saw less than an average of 10 asthma patients per year were excluded. Results: Overall, 51,511 acute asthma ED presentations occurred (~10,000/year). The average proportion of CXRs among presentations was 39.5% (2011-2015) with an average annual increase of 6.7%. From 2011-2015, CXR ordering varied across the five AHS zones (variation [V]: 25%; range: 26.0%-51.0%). Substantial variation was observed across ED sites V: 60%; range: 5.9-66.4%) and physicians (V: 89%; range: 1.4-90.6%). The mean CXR ordering among physicians was 44%. Conclusion: From 2011-2015, CXR use among acute asthma ED presentations has increased. Substantial variation in CXR use suggests that evidence-based interventions are needed to improve imaging appropriateness.

The role of seasonal grass pollen on childhood asthma emergency department presentations

Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations. To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season. A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma. A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m(3) , the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001). This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m(3) , independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.

The Role of Seasonal Grass Pollen on Childhood Asthma Emergency Department Presentations

Identifying high grass pollen days is important for asthma management programs that issue warnings to patients who are at an increased risk of an asthma attack due to grass pollen exposure. We sought to examine the association between increasing ambient concentrations of grass pollen and asthma Emergency Department (ED) presentations in children during the 2003 grass pollen season in Melbourne, Victoria; and whether there was any added influence from thunderstorms. A short time series ecological study was conducted of ED presentations for asthma in children in Melbourne, Victoria and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine the dose-response associations between daily grass pollen levels and mean daily ED attendances for asthma among children. A smoothed plot suggested a dose-response association - as ambient grass pollen increased to about 19 grains/m3 the same day risk of childhood ED presentations also increased (p < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, p < 0.001). This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and increasing levels of ambient grass pollen below 20 grains/m3, independent of thunderstorm-associated asthma. Lower levels of pollen may contribute to asthma symptoms, so the limits of the pollen season may need to be reviewed and this in turn could affect the timing of immunotherapy.

Air pollution and childhood asthma emergency hospital admissions: Estimating intra-city regional variations

In recent years childhood asthma has increased. Although the precipitants of childhood asthma are yet to be established possible contributing factors are local ambient air pollutants. This study aims to assess associations of regional ambient air pollutants on emergency department childhood asthma presentations across four regions of the city of Melbourne, Australia. Daily emergency department (ED) presentations for asthma in children were studied for the years 2000 and 2001. Estimates of local air pollutant levels were obtained using simulation modelling techniques. Generalized Additive Models were used to examine associations between combined local levels of air pollutants and childhood asthma ED presentations adjusting for seasonal variation, day of week effects, and meteorological variables. There was consistent associations between childhood ED asthma presentations and regional concentration of PM10, with a strongest association of RR = 1.17 (95% CI 1.05 to 1.31) in the central district of Melbourne. NO2 and Ozone was associated with increased childhood asthma ED presentations in the Western districts. This study suggests that regional concentrations of PM10 may have a significant effect on childhood asthma morbidity. In addition, ozone may play a role however, its effect may vary by geographical region.