Risk factors for an intensive care unit admission in children with asthma

Features of children with critical asthma hospitalized in a pediatric intensive care unit: Results from the ICU-3A study

INTRODUCTION

Despite improvements in long-term asthma treatment, an increasing number of children are being hospitalized in pediatric intensive care units (PICU) for asthma. The main objective of this study was to describe a recent cohort of children hospitalized in PICU for asthma to identify risk factors associated with a need for respiratory support, and multiple PICU stays.

METHODS

We conducted a retrospective cohort study in three PICUs in Paris (intensive care units 3A Study), using medical files of children hospitalized for asthma between February 2019 and October 2020. Need for respiratory support was defined by the need for high-flow nasal cannula or mechanical ventilation (MV) (either noninvasive [NIV] or invasive [IMV]).

RESULTS

During the study period, 252 stays corresponding to 234 patients were analyzed. MV was required in 17.5% of stays, for significantly younger patients (2.37 vs. 4.18 years, p = 0.002). On multivariate analysis, a higher risk of progression to a need for respiratory support was found for children requiring magnesium sulfate or oxygen therapy ≥6 L/mn before PICU admission (RR 4.48; CI95% [1.85-10.89]; p = 0.001, and RR 2.86; CI95% [1.13-7.22]; p = 0.03, respectively), and those with atelectasis detected on chest radiography (RR 3.38; CI95% [1.43-8.00]; p < 0.01). Multiple PICU stays were associated with greater social deprivation (RR for French Deprivation Index 1.25; CI95% [1.03-1.51]; p = 0.03).

CONCLUSION

Children experiencing social deprivation are at greater risk of multiple PICU stays for severe asthma. After transfer to PICU, children with chest radiograph detected atelectasis on admission are at higher risk of needing respiratory support.

Severe asthma in children: Description of a large multidisciplinary clinical cohort

BACKGROUND

Children with severe asthma have substantial morbidity and healthcare utilization. Pediatric severe asthma is a heterogeneous disease, and a multidisciplinary approach can improve the diagnosis and management of these children.

METHODS

We reviewed the electronic health records for patients seen in the Severe Asthma Clinic (SAC) at UPMC Children's Hospital of Pittsburgh between August 2012 and October 2019.

RESULTS

Of the 110 patients in whom we extracted data, 46% were female, 48% were Black/African American, and 41% had ≥1 admission to the pediatric intensive care unit (PICU) for asthma. Compared to patients without a PICU admission, those with ≥1 PICU admission were more likely to be non-White (64.4% vs. 41.5%, p = 0.031) and more atopic (eosinophil count geometric mean = 673 vs. 319 cells/mm3 , p = 0.002; total IgE geometric mean = 754 vs. 303 KU/L, p = 0.003), and to have lower pre-bronchodilator FEV1 (58.6% [±18.1%] vs. 69.9% [±18.7%], p = 0.002) and elevated FeNO (60% vs. 22%, p = 0.02). In this cohort, 84% of patients were prescribed high-dose ICS/LABA and 36% were on biologics. Following enrollment in the SAC, severe exacerbations decreased from 3.2/year to 2.2/year (p < 0.0001); compared to the year before joining the SAC, in the following year the group had 106 fewer severe exacerbations.

CONCLUSIONS

This large cohort of children with severe asthma had a high level of morbidity and healthcare utilization. Patients with a history of PICU admissions for asthma were more likely to be nonwhite and highly atopic, and to have lower lung function. Our data support a positive impact of a multidisciplinary clinic on patients with severe childhood asthma.

Severe acute asthma at the pediatric intensive care unit: can we link the clinical phenotypes to immunological endotypes?

INTRODUCTION

The clinical phenotype of severe acute asthma at the pediatric intensive care unit (PICU) is highly heterogeneous. However, current treatment is still based on a 'one-size-fits-all approach'.

AREAS COVERED

We aim to give a comprehensive description of the clinical characteristics of pediatric patients with severe acute asthma admitted to the PICU and available immunological biomarkers, providing the first steps toward precision medicine for this patient population. A literature search was performed using PubMed for relevant studies on severe acute (pediatric) asthma.

EXPERT OPINION

Omics technologies should be used to investigate the relationship between cellular molecules and pathways, and their clinical phenotypes. Inflammatory phenotypes might guide bedside decisions regarding the use of corticosteroids, neutrophil modifiers and/or type of beta-agonist. A next step toward precision medicine should be inclusion of these patients in clinical trials on biologics.

Racial, ethnic, and socioeconomic disparities in paediatric critical care in the USA

In an era of tremendous medical advancements, it is important to characterise and address inequities in the provision of health care and in outcomes. There is a large body of evidence describing such disparities by race or ethnicity and socioeconomic position in critically ill adults; however, this important issue has received less attention in children and adolescents (aged ≤21 years). This Review presents a summary of the available evidence on disparities in outcomes in paediatric critical illness in the USA as a result of racism and socioeconomic privilege. The majority of evidence of racial and socioeconomic disparities in paediatric critical care originates from the USA and is retrospective, with only one prospective intervention-based study. Although there is mixed evidence of disparities by race or ethnicity and socioeconomic position in general paediatric intensive care unit admissions and outcomes in the USA, there are striking trends within some disease processes. Notably, there is evidence of disparities in management and outcomes for out-of-hospital cardiac arrest, asthma, severe trauma, sepsis, and oncology, and in families' perceptions of care. Furthermore, there is clear evidence that critical care research is limited by under-enrolment of participants from minority race or ethnicity groups. We advocate for rigorous research standards and increases in the recruitment and enrolment of a diverse range of participants in paediatric critical care research to better understand the disparities observed, including the effects of racism and poverty. A clearer understanding of when, where, and how such disparities affect patients will better enable the development of effective strategies to inform practice, interventions, and policy.

Effect of Obesity on Asthma Severity in Urban School Children of Kanpur, India: An Analytical Cross-Sectional Study

The prevalence of both Obesity and Asthma is increasing worldwide. Various epidemiological data has linked obesity with the development and severity of asthma in children. The aim of this study was to assess if any relationship exists between obesity and asthma in children. The study population included school children aged 5 to 18 years. A total of 320 asthma cases and 300 controls were included in our study. Association analysis of obesity and asthma based on epidemiological basis was measured. Out of 320 cases, 61 children were found to have moderate persistent asthma. Out of 61 moderate persistent asthma cases, 50 children were selected randomly and divided into two groups. Group I included 25 obese moderate persistent asthmatics and Group II included 25 non-obese moderate persistent asthmatics. Forced expiratory volume in one second (FEV₁), Forced vital capacity (FVC), Forced expiratory flow (FEF_25-75%), Peak expiratory flow (PEF) were measured with spirometry and Peak expiratory flow meter. Statistical analysis was done by Odds ratio and p value. Out of 320 cases, 97 were obese and 223 were non-obese. Out of 300 controls, 46 were obese and 254 were non-obese. Exposure rate for cases and controls were 30.31% and 15.33% respectively. Odds ratio was 2.40. χ² value was 19.56 with p value < 0.05.FEV₁, FVC, FEF_{25-75%, PEF} for Group-1 were 66.3 ± 9.9, 63.5 ± 4.2, 54.2 ± 5.7, 67.4 ± 8.4 respectively and FEV₁, FVC, FEF_25-75%, PEF for Group-2 were 74.07 ± 3.5, 77.4 ± 7.2, 60.1 ± 2.1, 71.6 ± 2.4 respectively and p values were < 0.001, < 0.001, < 0.001, < 0.05 respectively which is statistically significant. Children who are obese are more likely to develop severe asthma than those who were not obese.

Development and validation of a risk score to identify children at risk of life-threatening asthma

OBJECTIVE

To develop and validate a prediction risk score for identification of children at risk of developing life-threatening asthma (LTA).

METHODS

Our study utilized existing medical records and retrospective analysis to develop and validate a risk score. The study population included children aged 2-17 years, admitted with a primary diagnosis of asthma, to Sydney Children's Hospital between 2011-2016. Children admitted in the intensive care unit with asthma at risk of LTA (cases) and those admitted into general ward (comparison group), were randomly divided into a derivation and a validation cohort. Candidate predictors from derivation cohort were selected through multivariable regression, which were used to estimate each child's risk of developing LTA in the validation cohort. Predictive performance of the risk score was evaluated by the area under the receiver operating characteristic curve (AUROC) and Hosmer-Lemeshow goodness-of-fit test.

RESULTS

The study population comprised of 1171 children; 586 in the derivation and 585 in the validation cohort. Four independent candidate variables from derivation cohort (age at admission, socioeconomic status, a family history of asthma/atopy and previous asthma hospitalizations) were retained in the predictive model (AUROC 0.759; 95% CI, 0.694-0.823), with a sensitivity of 78.5% and specificity of 46.6%.

CONCLUSIONS

Our risk algorithm based on routinely collected clinical data may be used to develop a user-friendly risk score for early identification and monitoring of children at risk of developing LTA.

Factors Associated with Failure of Intermittent Nebulization with Short-Acting Beta-Agonists in Children with Severe Asthma Exacerbation

Purpose

Intermittent nebulization of short-acting beta-agonists (SABA) is the initial treatment of choice for children with asthma exacerbation. However, children with severe asthma exacerbation (SAE) may not show an adequate response and need aggressive stepwise therapy. We aimed to explore factors associated with a poor response to intermittent nebulized SABA in children with SAE.

Methods

A retrospective cohort study of children with SAE diagnosed according to the definition of the British Guidelines on the Management of Asthma, who were admitted at Hat Yai Hospital from January 1, 2015, to December 31, 2017. All children were treated with intermittent SABA nebulization. Treatment failure was defined as children needing escalated therapy. Logistic regression with confounding score adjustment was used to explore the predictors of treatment failure.

Results

One hundred thirty-three children were included in the analysis, 59 were in the failure group and 74 were in the success group. After adjusting for potential confounders, they were significantly associated with a previous history of intubation (adjusted OR 6.46, 95% CI 1.13 to 36.79, p=0.036), receiving <3 doses of nebulized salbutamol in the emergency room (ER, aOR 3.21, 95% CI 1.15 to 9.02, p=0.027), ER measured oxygen saturation (SpO₂) <92% (adjusted OR 3.02, 95% CI 1.18 to 7.75, p=0.022), and exacerbation triggered by pneumonia (adjusted OR 2.67, 95% CI 1.19 to 6.00, p=0.017).

Conclusion

We identified four prognostic factors of treatment failure in children with SAE: a previous history of intubation; receiving <3 doses of nebulized salbutamol in the ER, SpO₂ at ER <92%; and exacerbation triggered by pneumonia. Further prospective studies are required to confirm our findings before clinical implementation.

Risk factors for intensive care admission in children with severe acute asthma in the Netherlands: a prospective multicentre study

Rationale

Severe acute asthma (SAA) can be fatal, but is often preventable. We previously observed in a retrospective cohort study, a three-fold increase in SAA paediatric intensive care (PICU) admissions between 2003 and 2013 in the Netherlands, with a significant increase during those years of numbers of children without treatment of inhaled corticosteroids (ICS).

Objectives

To determine whether steroid-naïve children are at higher risk of PICU admission among those hospitalised for SAA. Furthermore, we included the secondary risk factors tobacco smoke exposure, allergic sensitisation, previous admissions and viral infections.

Methods

A prospective, nationwide multicentre study of children with SAA (2–18 years) admitted to all Dutch PICUs and four general wards between 2016 and 2018. Potential risk factors for PICU admission were assessed using logistic regression analyses.

Measurements and main results

110 PICU and 111 general ward patients were included. The proportion of steroid-naïve children did not differ significantly between PICU and ward patients. PICU children were significantly older and more exposed to tobacco smoke, with symptoms >1 week prior to admission. Viral susceptibility was not a significant risk factor for PICU admission.

Conclusions

Children with SAA admitted to a PICU were comparable to those admitted to a general ward with respect to ICS treatment prior to admission. Preventable risk factors for PICU admission were >7 days of symptoms without adjustment of therapy and exposure to tobacco smoke. Physicians who treat children with asthma must be aware of these risk factors.

Preventable risk factors for PICU admission among those with severe acute asthma are >7 days of symptoms without adjustment of therapy and environmental exposure to tobacco smoke, underlining the importance of smoking cessation of caregivershttps://bit.ly/3ezPzxT

The impact of social determinants of health on laryngotracheal stenosis development and outcomes

OBJECTIVES

The social determinants of health affect a wide range of health outcomes and risks. To date, there have been no studies evaluating the impact of social determinants of health on laryngotracheal stenosis (LTS). We sought to describe the social determinants in a cohort of LTS patients and explore their association with treatment outcome.

METHODS

Subjects diagnosed with LTS undergoing surgical procedures between 2013 and 2018 were identified. Matched controls were identified from intensive care unit (ICU) patients who underwent intubation for greater than 24 hours. Medical comorbidities, stenosis characteristics, and patient demographics were abstracted from the clinical record. Tracheostomy at last follow-up was recorded from the medical record and phone calls. Socioeconomic data was obtained from the American Community Survey.

RESULTS

One hundred twenty-two cases met inclusion criteria. Cases had significantly lower education compared to Tennessee (P = .009) but similar education rates as ICU controls. Cases had significantly higher body mass index (odds ratio [OR]: 1.04, P = .035), duration of intubation (OR: 1.21, P < .001), and tobacco use (OR: 1.21, P = .006) in adjusted analysis when compared to controls. Tracheostomy dependence within the case cohort was significantly associated with public insurance (OR: 1.33, P = .016) and chronic obstructive pulmonary disease (OR: 1.34, P = .018) in adjusted analysis.

CONCLUSION

Intubation practices, medical comorbidities and social determinants of health may influence the development of LTS and tracheostomy dependence after treatment. Identification of at-risk populations in ICUs may allow for prevention of tracheostomy dependence through the use of early tracheostomy and specialized follow-up.

LEVEL OF EVIDENCE

Level 3, retrospective review comparing cases and controls Laryngoscope, 130:1000-1006, 2020.

Management of severe asthma exacerbation: guidelines from the Société Française de Médecine d'Urgence, the Société de Réanimation de Langue Française and the French Group for Pediatric Intensive Care and Emergencies

BACKGROUND

The French Emergency Medicine Society, the French Intensive Care Society and the Pediatric Intensive Care and Emergency Medicine French-Speaking Group edited guidelines on severe asthma exacerbation (SAE) in adult and pediatric patients.

RESULTS

The guidelines were related to 5 areas: diagnosis, pharmacological treatment, oxygen therapy and ventilation, patients triage, specific considerations regarding pregnant women. The literature analysis and formulation of the guidelines were conducted according to the Grade of Recommendation Assessment, Development and Evaluation methodology. An extensive literature research was conducted based on publications indexed in PubMed™ and Cochrane™ databases. Of the 21 formalized guidelines, 4 had a high level of evidence (GRADE 1+/-) and 7 a low level of evidence (GRADE 2+/-). The GRADE method was inapplicable to 10 guidelines, which resulted in expert opinions. A strong agreement was reached for all guidelines.

CONCLUSION

The conjunct work of 36 experts from 3 scientific societies resulted in 21 formalized recommendations to help improving the emergency and intensive care management of adult and pediatric patients with SAE.

Respiratory pathogens and clinical outcomes in children with an asthma exacerbation: A systematic review

BACKGROUND

In asthmatic children, respiratory pathogens are identified in 60%-80% of asthma exacerbations, contributing to a significant burden of illness. The role of pathogens in the clinical evolution of exacerbations is unknown.

OBJECTIVE

We systematically reviewed the association between the presence of pathogens and clinical outcomes in children with an asthma exacerbation.

METHOD

PubMed, EMBASE, BIOSIS, and the Cochrane Central Register of Controlled Trials were searched up to October 2016 for studies reporting on respiratory pathogen exposure and clinical outcome. The Risk of Bias in Non-Randomized Studies of Interventions tool was used for quality assessment.

RESULTS

Twenty-eight observational studies (N = 4,224 children) reported on 112 different associations between exposure to any pathogen (n = 45), human rhinovirus (HRV; n = 34), atypical bacteria (n = 21), specific virus (n = 11), or bacteria (n = 1) and outcomes of exacerbation severity (n = 26), health care use (n = 38), treatment response (n = 19), and morbidity (n = 29). Restricting the analysis only to comparisons with a low to moderate risk of bias, we observed an association between HRV and higher exacerbation severity on presentation (regression p = .016) and between the presence of any pathogen and emergency department treatment failure (odds ratio [OR] = 1.57; 95% CI 1.04% to 2.37%). High-quality evidence for effect on morbidity or health care use is lacking.

CONCLUSIONS

Further research on the role of pathogen-treatment interaction and outcomes is required to inform the need for point-of-care, real-time testing for pathogens. Studies with a sufficiently large sample size that address selection bias, correctly adjust for confounding, and rigorously report core patient-centred outcomes are necessary to improve knowledge.

Characteristics of inner-city children with life-threatening asthma

BACKGROUND

Intensive care unit (ICU) admission is a risk factor for fatal asthma. Little is known about risk factors for pediatric ICU admissions for asthma.

OBJECTIVE

To examine characteristics of underserved minority children with prior ICU admissions for asthma.

METHODS

Baseline survey data, salivary cotinine levels, and allergen specific IgE serologic test results were obtained from children with uncontrolled asthma enrolled in a randomized clinical trial of a behavioral education environmental control intervention. Characteristics of children with and without prior ICU admission were compared using χ² and t tests. Logistic regression assessed significance of higher odds of prior ICU admission comparing factor-level categories.

RESULTS

Patients included 222 primarily African American (93.7%), male (56%), Medicaid-insured (92.8%) children with a mean (SD) age of 6.4 (2.7) years with uncontrolled asthma. Most (57.9%) had detectable cotinine levels, 82.6% were sensitized to more than 1 environmental allergen, and 27.9% had prior ICU admissions. Prior ICU patients were more likely to be very poor (<$10,000 per year) and sensitized to more than 1 allergen tested (most importantly mouse) (P < .05). Allergen sensitization in the groups did not differ for cockroach, cat, dog, Alternaria, Aspergillus, dust mite, grass, or tree. Although more ICU patients received combination controller therapy, they also overused albuterol. Only 27.4% of ICU patients received specialty care in the previous 2 years, which was not significantly different from non-ICU patients.

CONCLUSION

Children with high mortality risk, including history of ICU admission, were twice as likely to live in extreme poverty, have atopy (particularly mouse allergen), use combination controller therapy, and overuse albuterol.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01981564.

[Treatment with high-flow oxygen therapy in asthma exacerbations in a paediatric hospital ward: Experience from 2012 to 2016]

OBJECTIVE

To assess the experience with oxygen therapy with a high flow nasal cannula (HFNC) in hospital on patients with asthmatic exacerbation (AE) in a paediatric ward, and to assess the clinical outcome according with the initial oxygen flow (15lpm or <15lpm).

METHODS

This was a retrospective study of children aged 4 to 15 years with AE admitted to a paediatric ward in a tertiary level hospital between 2012 and 2016. Two groups of patients were compared; Group 1: patients treated with HFNC, and Group 2: patients treated with conventional oxygen therapy. A logistic regression model was constructed in order to identify predictive variables of HFNC. The clinical outcome of the patients was also compared according to the initial flow of HFNC (15lpm VS <15lpm).

RESULTS

The study included a total of 536 patients with AE, 40 (7.5%) of whom required HFNC. The median age was 5 (4-6) years. Heart rate (HR), respiratory rate (RR) and Pulmonary Score (PS) significantly decreased at 3-6hours after starting HFNC in Group 1. In the multivariate analysis, patients with high Pulmonary Score values and greater number of previous admissions required HFNC more frequently. Patients treated with an initial flow of 15lpm were admitted less frequently to the PICU than those with an initial flow less than 15lpm (13% vs 47%, p=.05).

CONCLUSION

HFNC seems to be a useful therapy for asthma exacerbation in paediatric wards. Severity of Pulmonary Score and the number of previous admissions could enable a risk group that needs HFNC to be identified.

Children with severe acute asthma admitted to Dutch PICUs: A changing landscape

The number of children requiring pediatric intensive care unit (PICU) admission for severe acute asthma (SAA) around the world has increased.

OBJECTIVES

We investigated whether this trend in SAA PICU admissions is present in the Netherlands.

METHODS

A multicenter retrospective cohort study across all tertiary care PICUs in the Netherlands. Inclusion criteria were children (2-18 years) hospitalized for SAA between 2003 and 2013. Data included demographic data, asthma diagnosis, treatment, and mortality.

RESULTS

In the 11-year study period 590 children (660 admissions) were admitted to a PICU with a threefold increase in the number of admissions per year over time. The severity of SAA seemed unchanged, based on the first blood gas, length of stay and mortality rate (0.6%). More children received highflow nasal cannula (P < 0.001) and fewer children needed invasive ventilation (P < 0.001). In 58% of the patients the maximal intravenous (IV) salbutamol infusion rate during PICU admission was 1 mcg/kg/min. However, the number of patients treated with IV salbutamol in the referring hospitals increased significantly over time (P = 0.005). The proportion of steroid-naïve patients increased from 35% to 54% (P = 0.004), with a significant increase in both age groups (2-4 years [P = 0.026] and 5-17 years [P = 0.036]).

CONCLUSIONS

The number of children requiring PICU admission for SAA in the Netherlands has increased. We speculate that this threefold increase is explained by an increasing number of steroid-naïve children, in conjunction with a lowered threshold for PICU admission, possibly caused by earlier use of salbutamol IV in the referring hospitals.

Frequency of health service use in the year prior to asthma death

OBJECTIVE

High frequency health service use (HSU) is associated with poorly controlled asthma, and is a recognized risk factor for near-fatal or fatal asthma. The objective of this study was to describe the frequency of HSU in the year prior to asthma death.

METHODS

Individuals aged 0-99 years who died from asthma from April 1996 to December 2011 in Ontario, Canada were identified as cases. Cases were matched to 4-5 live asthma controls by age, sex, rural/urban residence, socioeconomic status, duration of asthma and a co-diagnosis of COPD. HSU records in the year prior to death [hospitalization, emergency department (ED) and outpatient visits] were assembled. The association of prior HSU and asthma death was measured by conditional logistic regression models.

RESULTS

From 1996 to 2011, 1503 individuals died from asthma. While the majority of cases did not have increased HSU as defined in the study, compared to matched live asthma controls, the cases were 8-fold more likely to have been hospitalized two or more times (OR = 7.60; 95% CI: 4.90, 11.77), 13-fold more likely to have had three or more ED visits (OR = 13.28; 95% CI: 7.55, 23.34) and 4-fold more likely to have had five or more physician visits for asthma (OR = 4.41; 95% CI: 3.58, 5.42).

CONCLUSIONS

Frequency of HSU in the year prior was substantially higher in those died from asthma. Specifically, more than one asthma hospital admission, three ED visits or five physician visits increased the asthma mortality risk substantially and exponentially.

Medical and Social Determinants of Health Associated with Intensive Care Admission for Asthma in Children

RATIONALE

Risk factors for severe asthma exacerbations in children requiring admission to the intensive care unit (ICU) may occur in variety of medical, environmental, economic, and socioeconomic domains.

OBJECTIVES

We sought to characterize medical and sociodemographic risk factors among children who required admission to the intensive care unit for asthma.

METHODS

Data were obtained from the Greater Cincinnati Asthma Risk Study, a population-based, prospective, observational cohort of children admitted for treatment of acute asthma or bronchodilator-responsive wheezing. Data collected on 774 children included race, socioeconomic status, allergen sensitization, environmental exposures, psychosocial strain, and financial hardship. Analyses compared children admitted to the ICU to those admitted to a medical inpatient unit.

MEASUREMENTS AND MAIN RESULTS

One hundred sixty-one (20.9%) children required admission to intensive care. There was no difference in sex, race, insurance status, caregiver educational level, income, financial strain, psychological distress, or marital status between the ICU and non-ICU cohorts. Risk for medication nonadherence assessed by parent report was not different between groups. Although previous hospital admission or emergency department visit history did not differ between the groups, prior ICU admission was more common among those admitted to the ICU at the index admission (27 vs. 16%, P = 0.002). Children requiring intensive care admission were more likely to be sensitized to multiple aeroallergens. Exposure to cigarette smoke (measured as salivary cotinine), although a risk factor for hospital admission, was negatively associated with risk of ICU admission.

CONCLUSIONS

Social and economic risk factors typically predictive of increased asthma morbidity, including exposure to tobacco smoke, were not associated with ICU admission among a population of children admitted to the hospital for treatment of acute asthma. Intrinsic disease factors, including allergic sensitization, may be more important predictors of ICU admission.

Assessment of asthma severity and control

BACKGROUND

Asthma is a disease of great variability. Untreated asthma can have lifelong implications in terms of lung growth as well as residual lung function throughout life. Close attention to establishing severity of the disease and level of control established in each patient through treatment are important to achieving the best results.

METHODS

Available English-language literature was reviewed. Citations were included based on the quality of the original paper and relevance to the specific aims of this primer.

RESULTS

Assessing intrinsic severity of the patient's disease at the first encounter using impairment measures of short-acting beta agonist use, nighttime awakenings, interference of disease with normal activity, and pulmonary function testing, as well as measures of patient risk of acute exacerbations is vitally important. At subsequent patient encounters, adjusting therapy based on both impairment and risk components of control will improve long-term outcomes.

CONCLUSION

Any practitioner undertaking to care for asthma patients should be conversant with the degrees of disease severity and levels of disease control on therapy. Application of these principles will maximize patient benefit from asthma care.

Need for intensive care in patients admitted for asthma: Red flags from the social history

BACKGROUND AND OBJECTIVE

Asthma deaths in Australia are associated with illicit substance abuse, mental health problems and social issues. However, a large proportion of these deaths occurs out of hospital and is difficult to avert by the time the individuals seek medical attention. We hypothesized that these characteristics may also increase the risk for a patient to require intensive care admission when they present to emergency departments.

METHODS

We studied consecutive patients admitted to a tertiary metropolitan hospital with a primary diagnosis of asthma between January 2010 and January 2014. Clinical and demographical data were obtained from chart review. The patient's postcode was used as a surrogate for socioeconomic status.

RESULTS

There were 482 asthma patients admitted during the study period, of which 39 required intensive care. Ten patients admitted to intensive care (26%) used illicit drugs compared with 29 (7%) of those admitted to the ward (adjusted odds ratio: 3.6, P = 0.012). For illicit users, nonadherence to preventer therapy was associated with an even higher risk of intensive care unit admission. Socioeconomic index was lower in the group requiring intensive care admission. The frequency of psychiatric diagnoses was similar in both groups.

CONCLUSION

Among patients admitted to hospital for asthma, illicit substance abuse is a strong independent risk factor for intensive care requirement. Preventer therapy nonadherence further increases this risk. Lower socioeconomic status is also associated with increased risk. These historical features should be actively sought on admission and may serve as useful 'red flags' to prompt consideration of intensive monitoring.

In Utero exposure to genistein enhanced intranasal house dust mite allergen-induced respiratory sensitization in young adult B6C3F1 mice

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental immunotoxic effects are increasing. To understand how in utero GEN exposure may modulate postnatal respiratory sensitization, we conducted a time course study using a common household allergen (house dust mites: HDM; 10μg/mouse) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20mg/kg bw). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly doses of HDM extracts, and they were euthanized at day 3 following the final HDM exposure at four different time points (postnatal day (PND) 80, 120, 160, and 200). In utero GEN combined with postnatal HDM exposures (GEN+HDM) increased total IgE production in both young female and male B6C3F1 offspring (e.g., PND 80 in females and PND 120 in males). Increased antigen-specific IgG1, IgG2a and IgG2b levels were also observed at various time points in both female and male offspring. In addition, increases in macrophage number in bronchoalveolar lavage fluid of both female and male GEN+HDM offspring at PND 80 and PND 120, respectively, were observed when compared to the vehicle group. For T cells, an increase over the vehicle in female GEN+HDM offspring was observed at PND 80. Due to similar patterns of increases, it seems likely that GEN+HDM-induced increases in total IgE and macrophages are related. Overall, in utero GEN plus later-life HDM exposures exert increases in total IgE and HDM-specific IgG production as well as macrophage recruitments to the lung in young adult mice.

Contributing factors to the development of childhood asthma: working toward risk minimization

Asthma is the most common chronic disease in childhood, and considerable research has been undertaken to find ways to prevent its development and reduce its prevalence. For such interventions to be successful, risk factors for asthma emergence should be identified and clearly defined. Data are robust for some of them, including atopy, viral infections and exposure to airborne irritants, whereas it is less conclusive for others, such as aeroallergen exposure and bacterial infections. Several interventions for asthma prevention, including avoidance and pharmacotherapy, have been attempted. However, most of them have furnished equivocal results. Various issues hinder the establishment of risk factors for asthma development and reduce the effectiveness of interventions, including the complexity of the disease and the fluidity of the developing systems in childhood. In this review, we revisit the evidence on pediatric asthma risk factors and prevention and discuss issues that perplex this field.

Factors associated with asthma control in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Effective control of asthma is the primary goal of its treatment. Despite an improved understanding of asthma pathogenesis and accessibility of novel therapies, the rate of uncontrolled asthma remains high.

OBJECTIVE

To find potential factors associated with asthma control in patients with aspirin-exacerbated respiratory disease (AERD).

METHODS

Clinical data were collected from a specifically structured questionnaire. Demographics, a history of upper airway symptoms, asthma course, exacerbations expressed as emergency department (ED) visits/hospitalizations, and asthma treatment were considered. Spirometry, skin prick tests, total IgE concentration, and blood eosinophil count were evaluated. Asthma control was assessed through the Asthma Control Test (ACT).

RESULTS

Out of 201 AERD patients, 41 (20.4%), 69 (34.3%), and 91 (45.3%) had controlled, partially controlled, and uncontrolled asthma, respectively. A multivariate ordered logistic regression analysis revealed that hospitalizations for asthma in the previous 12 months (OR 2.88; 95%CI, 1.11-7.46), ED visits for asthma throughout its duration (OR 1.05; 95%CI, 1.004-1.10), and total IgE concentration (OR 1.28; 95%CI, 1.02-1.60) were positively associated with poor asthma control, whereas FEV1 values (OR 0.98; 95%CI, 0.96-0.99) and medical care at a referential specialty clinic (OR 0.50; 95%CI, 0.27-0.95) were positively associated with good asthma control.

CONCLUSIONS

The prevalence of uncontrolled asthma in AERD patients is high and similar to that observed in different asthmatic populations. Owing both to the specificity and complexity of the disease, AERD patients should stay under regular care of well experienced referential medical centers to ensure that this asthma phenotype is dealt with effectively.

Management of status asthmaticus in children

Recent literature on paediatric status asthmaticus (PSA) confirms an increasing percentage of admissions to paediatric intensive care units. PSA is a medical emergency that can be fatal and needs careful and prompt intervention. The severity of PSA is mainly determined by clinical judgement of signs and symptoms. Peak flow measurements and serial lung function measurements are not reliable in PSA. Validated clinically useful instruments are lacking. The three main factors that are involved in the pathophysiology of PSA, bronchoconstriction, mucus plugging and airway inflammation need to be addressed to optimise treatment. Initial therapies include supplementation of oxygen, repetitive administration of rapid acting β2-agonists, inhaled anticholinergics in combination with systemic glucocorticosteroids and intravenous magnesium sulphate. Additional treatment modalities may include methylxanthines, DNase, ketamine, sodium bicarbonate, heliox, epinephrine, non-invasive respiratory support, mechanical ventilation and inhalational anaesthetics.

Acute asthma exacerbations in childhood: risk factors, prevention and treatment

Asthma is a heterogeneous disease more appropriately seen as a syndrome rather than a single pathologic entity. Although it can remain quiescent for extended time periods, the inflammatory and remodeling processes affect the bronchial milieu and predispose to acute and occasionally severe clinical manifestations. The complexity underlying these episodes is enhanced during childhood, an era of ongoing alterations and maturation of key biological systems. In this review, the authors focus on such sudden-onset events, emphasizing on their diversity on the basis of the numerous asthma phenotypes.

Managing the paediatric patient with an acute asthma exacerbation

Children with acute asthma exacerbations frequently present to an emergency department with signs of respiratory distress. The most severe episodes are potentially life-threatening. Effective treatment depends on the accurate and rapid assessment of disease severity at presentation. This statement addresses the assessment, management and disposition of paediatric patients with a known diagnosis of asthma who present with an acute asthma exacerbation, especially preschoolers at high risk for persistent asthma. Guidance includes the assessment of asthma severity, treatment considerations, proper discharge planning, follow-up, and prescription for inhaled corticosteroids to prevent exacerbation and decrease chronic morbidity.

Pediatric asthma: natural history, assessment, and treatment

Wheezing and childhood asthma are not synonymous but rather comprise a heterogeneous group of conditions that have different outcomes over the course of childhood. Most infants who wheeze have a transient condition associated with diminished airway function at birth and have no increased risk of asthma later in life. However, children with persistent wheezing throughout childhood and frequent exacerbations represent the main challenge today. Studying the natural history of asthma is important for the understanding and accurate prediction of the clinical course of different phenotypes. To date, a great improvement has been achieved in reducing the frequency of asthma symptoms. However, neither decreased environmental exposure nor controller treatment, as recommended by the recent National Asthma Education And Prevention Program, can halt the progression of asthma in childhood or the development of persistent wheezing phenotype. This review focuses on the recent studies that led to the current understanding of asthma phenotypes in childhood and the recommended treatments.

Predictors of symptoms are different from predictors of severe exacerbations from asthma in children

BACKGROUND

Asthma therapy is typically prescribed and titrated based on patient or parent self-report of symptoms. No longitudinal studies have assessed the relationship between symptoms and severe asthma exacerbations in children. The goal of our study was (1) to assess the association of asthma symptoms with severe asthma exacerbations and (2) to compare predictors of persistent asthma symptoms and predictors of severe asthma exacerbations.

METHODS

The Childhood Asthma Management Program was a multicenter clinical trial of 1,041 children randomized to receive budesonide, nedocromil, or placebo (as-needed β-agonist). We conducted a post hoc analysis of diary cards that were completed by subjects on a daily basis to categorize subjects as having persistent vs intermittent symptoms. We defined a severe asthma exacerbation as an episode requiring ≥ 3 days use of oral corticosteroids, hospitalization, or ED visit due to asthma based on self-report at study visits every 4 months.

RESULTS

While accounting for longitudinal measures, having persistent symptoms from asthma was significantly associated with having severe asthma exacerbations. Predictors of having persistent symptoms compared with intermittent symptoms included not being treated with inhaled corticosteroids, lower FEV(1)/FVC ratio, and a lower natural logarithm of provocative concentration of methacholine producing a 20% decline in FEV(1) (lnPC(20)). Predictors of having one or more severe asthma exacerbations included younger age, history of hospitalization or ED visit in the prior year, ≥ 3 days use of oral corticosteroids in the prior 3 months, lower FEV(1)/FVC ratio, lower lnPC(20), and higher logarithm to the base 10 eosinophil count; treatment with inhaled corticosteroids was predictive of having no severe asthma exacerbations.

CONCLUSIONS

Patients with persistent symptoms from asthma were more likely to experience severe asthma exacerbations. Nevertheless, demographic and laboratory predictors of having persistent symptoms are different from predictors of severe asthma exacerbations. Although symptoms and exacerbations are closely related, their predictors are different. The current focus of the National Asthma Education and Prevention Program guidelines on the two separate domains of asthma control, impairment and risk, are supported by our analysis.

Factors associated with the development of severe asthma exacerbations in children

BACKGROUND

Asthma exacerbations are one of the most common causes of hospitalization in children and account for approximately 10,000 intensive care unit (ICU) admissions per year in the United States. Despite the prevalence of this disease in children, the factors associated with the development of these severe exacerbations are largely unknown.

METHODS

A retrospective case-control study was conducted involving all eligible children admitted to the hospital with asthma for a 1-year period. Potential associated factors and outcomes of children admitted to the ICU with a severe exacerbation (cases) were compared to those of children with acute asthma admitted to the ward (controls).

RESULTS

A total of 188 children were hospitalized with asthma during the study period, 57 (30%) of whom required admission to the ICU. There were no differences in age, gender, or race between cases and controls. Children admitted to the ICU were significantly more likely to have an allergy or irritant-triggered exacerbation than children admitted to the ward (OR 3.9; 95% CI 1.9-8.2; p = .0003). Additionally, children in the ICU had a significantly shorter duration of illness before being admitted to the hospital compared to those admitted to the ward (1.7 ± 2.3 vs. 3.4 ± 4.8 days; p = .002).

CONCLUSIONS

In this retrospective review, severe asthma exacerbations in children are associated with a more rapid onset of symptoms and are more likely to be associated with allergens or irritants, supporting the importance of atopy in this population.

Multicenter study of chronic asthma severity among emergency department patients with acute asthma

OBJECTIVE

The initiation of controller therapy for asthma depends on chronic asthma severity. To facilitate initiation of inhaled corticosteroids (ICSs), the preferred controller therapy, in the emergency department (ED), the objective of the study was to describe chronic asthma severity, as defined by the national asthma guidelines, among children presenting to the ED with acute asthma.

METHODS

Investigators at 14 U.S. sites prospectively enrolled consecutive children 2–17 years presenting to the ED with acute asthma. Three factors (daytime symptoms, nighttime symptoms, and medication usage) were used to categorize children into four chronic asthma severity groups: intermittent, mild persistent, moderate persistent or severe persistent.

RESULTS

This multistate cohort of 311 children had a mean age of 7.7 years, was 51% Black, and 89% had a primary care provider (PCP). Regarding chronic severity, 18% were intermittent and 82% persistent: 37% mild persistent, 24% moderate persistent, and 20% severe persistent. Chronic severity groups did not differ by demographics or PCP status. Patients with persistent asthma were more likely to report moderate-severe asthma symptoms (58% versus 19%; p < .001), poor asthma control (2% versus 18%; p = .002), and more ED visits (median, 2 versus 1; p < .001) in the past year. The groups did not differ in acute asthma severity, ED treatment, or admission rate. Rate of discharge prescription for ICSs was low, albeit higher among children with persistent asthma (24% versus 4%; p = .003).

CONCLUSIONS

The high prevalence of persistent asthma among ED patients exceeds the prevalence reported previously, and supports ED initiation of ICS, as recommended by national guidelines.

Management of severe asthma in children

Children who are referred to specialist care with asthma that does not respond to treatment (problematic severe asthma) are a heterogeneous group, with substantial morbidity. The evidence base for management is sparse, and is mostly based on data from studies in children with mild and moderate asthma and on extrapolation of data from studies in adults with severe asthma. In many children with severe asthma, the diagnosis is wrong or adherence to treatment is poor. The first step is a detailed diagnostic assessment to exclude an alternative diagnosis ("not asthma at all"), followed by a multidisciplinary approach to exclude comorbidities ("asthma plus") and to assess whether the child has difficult asthma (improves when the basic management needs, such as adherence and inhaler technique, are corrected) or true, therapy-resistant asthma (still symptomatic even when the basic management needs are resolved). In particular, environmental causes of secondary steroid resistance should be identified. An individualised treatment plan should be devised depending on the clinical and pathophysiological characterisation. Licensed therapeutic approaches include high-dose inhaled steroids, the Symbicort maintenance and reliever (SMART) regimen (with budesonide and formoterol fumarate), and anti-IgE therapy. Unlicensed treatments include methotrexate, azathioprine, ciclosporin, and subcutaneous terbutaline infusions. Paediatric data are needed on cytokine-specific monoclonal antibody therapies and bronchial thermoplasty. However, despite the interest in innovative approaches, getting the basics right in children with apparently severe asthma will remain the foundation of management for the foreseeable future.

Consistently very poorly controlled asthma, as defined by the impairment domain of the Expert Panel Report 3 guidelines, increases risk for future severe asthma exacerbations in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

BACKGROUND

Identification of patients at risk for asthma exacerbations can assist physicians in addressing disease management and improve asthma-related health outcomes.

OBJECTIVE

We sought to evaluate whether level of impairment, as defined by the 2007 asthma guidelines, predicts risk for future asthma exacerbations.

METHODS

The study included children aged 6 to 11 years (n = 82) and adolescent/adult patients aged 12 years and older (n = 725) from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study with data representing all components of the impairment domain of the asthma guidelines at baseline, month 12, and month 24. Patients were categorized into 2 cohorts: (1) consistently very poorly controlled (VPC) asthma from baseline through 2 years of follow-up and (2) improved from VPC asthma at baseline (including patients who improved to not well-controlled or well-controlled asthma), with improvement maintained through 2 years of follow-up. Odds ratios (ORs) and 95% CIs for risk of asthma exacerbations at month 30 were generated by using multivariable logistic regression by age group.

RESULTS

After adjustment, children with consistently VPC asthma over the 2-year period demonstrated a 6-fold increased risk of hospitalization, emergency department visit, or corticosteroid burst (OR, 6.4; 95% CI, 1.2-34.5) compared with the improved group. Adolescent/adult patients with consistently VPC asthma were more likely to have a corticosteroid burst (OR, 2.8; 95% CI, 1.7-4.8) or have a hospitalization, emergency department visit, or corticosteroid burst (OR, 3.2; 95% CI, 1.9-5.3).

CONCLUSIONS

Consistently VPC asthma, as defined by the impairment domain of the 2007 asthma guidelines, is strongly predictive of future asthma exacerbations.

Asthma morbidity among inner-city adolescents receiving guidelines-based therapy: role of predictors in the setting of high adherence

BACKGROUND

With the expanding effort to provide guidelines-based therapy to adolescents with asthma, attention must be directed to evaluating which factors predict future asthma control when guidelines-based management is applied.

OBJECTIVE

We evaluated the role of fraction of exhaled nitric oxide in parts per billion, markers of allergic sensitization, airway inflammation, and measures of asthma severity in determining future risk of asthma symptoms and exacerbations in adolescents and young adults participating in the Asthma Control Evaluation study.

METHODS

Five hundred forty-six inner-city residents, ages 12 through 20 years, with persistent asthma were extensively evaluated at study entry for predictors of future symptoms and exacerbations over the subsequent 46 weeks, during which guidelines-based, optimal asthma management was offered. Baseline measurements included fraction of exhaled nitric oxide in parts per billion, total IgE, allergen-specific IgE, allergen skin test reactivity, asthma symptoms, lung function, peripheral blood eosinophils, and, for a subset, airway hyperresponsiveness and sputum eosinophils.

RESULTS

The baseline characteristics we examined accounted for only a small portion of the variance for future maximum symptom days and exacerbations--11.4% and 12.6%, respectively. Future exacerbations were somewhat predicted by asthma symptoms, albuterol use, previous exacerbations, and lung function, whereas maximum symptom days were predicted, also to a modest extent, by symptoms, albuterol use, and previous exacerbations, but not lung function.

CONCLUSION

Our findings demonstrate that the usual predictors of future disease activity have little predictive power when applied to a highly adherent population with persistent asthma that is receiving guidelines-based care. Thus, new predictors need to be identified that will be able to measure the continued fluctuation of disease that persists in highly adherent, well-treated populations such as the one studied.

The natural history of fatal childhood asthma--a case from the Isle of Wight Birth Cohort

Subjects with severe and unstable asthma are at high risk of fatal asthma attack. We describe a case of fatal childhood asthma in an 11-year old girl whose asthma was apparently stable with supranormal lung function and identify additional characteristics that should be considered as increasing the risk for fatal asthma. This opportunity was provided by this girl's participation in the Isle of Wight Whole Population Birth Cohort Study. Prospectively collected data identified her as an early-onset persistent wheezer with significant allergic comorbidity. She was highly atopic with multiple allergen sensitization and a total IgE exceeding 5000 Ku/L (normal range: 0-180 ku/l) at 10 years. Additionally at that age, whilst possessing normal lung function (FEV(1) 2.15 Litres; 110% predicted), she was found to have marked bronchial hyper-responsiveness (PC(20) Methacholine 1.71 mg/ml). At the age of 11 years, despite apparent clinical stability and use of regular controller asthma therapy, she suffered a fatal acute asthma attack that may have been related to acute allergen exposure. This report provides further insight into factors associated with fatal childhood asthma. We propose that highly atopic children with early onset persistent asthma are at a higher risk of fatal asthma even if their asthma is apparently stable and lung function is normal. Marked bronchial hyper-responsiveness provides a clue and should be assessed if there is concern.

[Is asthma still a life-threatening disease?]

After a substantial augmentation in the mid-1980s, mortality from asthma stabilized in France as in the other industrialized countries, probably because of ever more appropriate health care utilization and treatment. In 2004, there were 1099 death in metropolitan France with a principal cause listed as asthma (last published data), for a crude rate of 1.8 deaths per 100,000 inhabitants. Despite the fact that fewer people are dying of asthma, several studies show an excess of all-cause mortality among people with asthma compared with people without asthma. The prevalence of severe asthma does not appear to have diminished, and clinical data show that severe asthma remains potentially fatal, because of resistant phenotypes, among other reasons. Other investigations are necessary to determine the trends in the prevalence of severe asthma and to understand the nonrespiratory mortality of asthma patients. Vigilance and surveillance of severe asthma must be maintained.

FCER2: a pharmacogenetic basis for severe exacerbations in children with asthma

BACKGROUND

Although inhaled corticosteroids (ICSs) generally protect against severe exacerbations in asthma, they may result in elevated IgE levels, which are associated with exacerbations.

OBJECTIVE

To determine whether variation in the low-affinity IgE receptor gene, FCER2, is associated with severe exacerbations defined as emergency department visits and/or hospitalizations in patients with asthma on ICSs.

METHODS

We resequenced, then genotyped 10 FCER2 single nucleotide polymorphisms (SNPs) in 311 children randomized to inhaled budesonide as part of the Childhood Asthma Management Program. We evaluated the association of FCER2 variants with IgE levels and presence or absence of severe exacerbations over the 4-year clinical trial. We also evaluated differences in cellular expression of the novel FCER2 SNP, T2206C.

RESULTS

In white subjects, 3 FCER2 SNPs were significantly associated (P < .05) with elevated 4-year IgE level; each was also associated with increased severe exacerbations. Final multivariable models demonstrated associations between T2206C and severe exacerbations in both white and African American children (hazard ratio, 3.95; 95% CI, 1.64-9.51; and hazard ratio, 3.08; 95% CI, 1.00-9.47), despite ICS use. Interaction models supported a true gene-environment effect in white subjects (interaction P = .004). T2206C was also associated with decreased FCER2 expression (P = .02).

CONCLUSION

FCER2 predicts the likelihood of treatment protocol success in asthma. The associations of T2206C with IgE level, severe exacerbations, and FCER2 expression may provide a mechanistic basis for the observed findings.

CLINICAL IMPLICATIONS

Genetic variation in FCER2 may help form a prognostic model for ICS response in asthma.

Does current asthma control predict future health care use among black preschool-aged inner-city children?

OBJECTIVES

Factors predictive of future asthma must be identified among young inner-city children, who suffer disproportionately from asthma. We investigated whether current asthma control predicts future asthma-related health care use among inner-city preschool-aged children with asthma.

METHODS

A total of 150 inner-city preschool-aged children with asthma were followed prospectively for 6 months. At baseline, symptom frequency and reliever-medication use were assessed to classify children into National Asthma Education and Prevention Program-derived control categories. Long-term controller-medication use was also assessed, as well as asthma-related health care use at baseline and at 3 and 6 months.

RESULTS

The mean age was 4.4 years, 92% were black, and 39% reported long-term controller use. At baseline, 37% were classified as having mild-intermittent, 17% had mild-persistent, 21% had moderate-persistent, and 25% had severe-persistent asthma control. Significant changes in asthma control were observed over time, including 46% of children originally categorized with mild-intermittent asthma who had worsened asthma control by 3 months. Asthma control significantly predicted future health care use 3 months later but not 6 months later. Multivariate analyses showed that, once control status was known, reported use of long-term controller medication added little additional predictive value.

CONCLUSIONS

Among inner-city preschool-aged children, significant fluctuations in asthma control occur as early as 3 months after assessment. Poor control but not long-term controller-medication use is an independent predictor of future asthma-related health care use at 3 months but is not significantly predictive of 6-month outcomes. Therefore, clinicians caring for inner-city children with asthma should consider reassessing asthma control at least every 3 months to identify those at highest future risk and to provide early interventions.

[Characteristics of mild asthma: clinical signs and medication use. Position statement of the Mild Asthma Working Group (174)]

OBJECTIVE

To update on the state of knowledge in mild asthma (intermittent and persistent mild asthma, according to the GINA classification) review the literature, and the position statement of the French Mild Asthma Working Group.

METHODS

The French Mild Asthma Working Group (11 lung specialists, 4 paediatricians, 1 pharmacologist, and 1 general practitioner) selected, analysed, and summarised the literature on the descriptive epidemiology, physiopathology, clinical signs, and management of mild asthma. The position of the working group on the descriptive epidemiology (causal factors excluded) and the nature of the bronchial inflammation has been presented in a previous article. The present article focuses on the clinical features of mild asthma and the use of medication for it.

RESULTS

Mild asthma was more frequent, more symptomatic, and less well controlled in children than in adults. Its generally benign evolution may in some (<10%) cases be complicated by severe episodes. Patients with mild persistent asthma require controller medication every day: permanent low-dose inhaled corticosteroid monotherapy is the reference foundation treatment for persistent mild asthma.

CONCLUSIONS

The present findings should help clinicians and guide them in their approach to managing this condition.

Risk factors leading to hospital admission in Iranian asthmatic children

BACKGROUND

Asthma is one of the most common chronic diseases in the world, leading to an increased rate of hospitalization. We performed this study to better understand the factors leading to admission among asthmatic children.

METHODS

We performed a study among asthmatic children in a referral hospital for asthma and allergy in Tehran. Sixty-three cases were selected from asthmatic children admitted to the emergency room (ER) who still had an indication for ward or intensive care unit admission after primary treatment. Our control group was the asthmatic children discharged after primary treatment and patients who were referred to the asthma and allergy clinic (63 patients). Data were obtained by structured questionnaires filled out during clinical interviews.

RESULTS

There was a significant difference in mean age (5 years for cases vs. 6 years for controls; p = 0.049), personal and familial allergic history (69.8 and 57.1% for cases vs. 34.9 and 36.5% for controls; p < 0.01 and p = 0.02, respectively), history of recent respiratory infections (79.4% for cases vs. 49.2% for controls; p < 0.01), hospitalization history due to asthma (57.1% for cases vs. 23.8% for controls; p < 0.01) and regular use of inhaled corticosteroid (66.7% for cases vs. 33.3% for controls; p < 0.01).

CONCLUSIONS

Our findings confirm most previous observations, suggesting that recent respiratory infections, hospitalization, personal or familial allergy, disease severity and lower ages are important factors leading to hospitalization. We also found that regular clinical follow-up, regular use of inhaled corticosteroids, higher IgE levels and O2 saturation may lower the probability of hospitalization during asthmatic attacks.

Pediatric asthma admissions: chronic severity and acute exacerbations

Factors resulting in intensive care unit (ICU) admissions for asthma exacerbations remain largely unclear. We compared ICU and general pediatric ward admissions for asthma exacerbations. Charts of 56 (2- to 18-year-old) patients admitted consecutively to the ICU during a 1-year period for asthma exacerbations were compared with charts of 56 age-, sex-, race-, and era-matched patients admitted to a general pediatric ward. Few patients in both groups received oral steroids before admission. Children with different chronic asthma severities had comparable severities of acute exacerbation. In conclusion, acute asthma exacerbations dissociate in severity from chronic asthma and are under-treated with systemic corticosteroids.

Mild asthma: an expert review on epidemiology, clinical characteristics and treatment recommendations

This review is the synthesis of a working group on mild asthma. Mild asthma includes intermittent and persistent mild asthma according to the Global Initiative for Asthma (GINA) classification, and affects between 50% and 75% of asthmatic patients. Mild asthma is more frequent, more symptomatic, and less well controlled in children than in adults. Cohort studies from childhood to adulthood show that asthma severity usually remains stable over time. Nevertheless, mild asthma can lead to severe exacerbations, with a frequency ranging from 0.12 to 0.77 per patient-year. Severe exacerbations in mild asthma represent 30-40% of asthma exacerbations requiring emergency consultation. In mild asthma, inflammation and structural remodelling are constant, of varying intensity, but nonspecific. Therapy with inhaled corticosteroids (ICS) decreases bronchial inflammation, but has only a slight effect on structural remodelling, and, when stopped, inflammation immediately recurs. Permanent low-dose ICS therapy is the reference treatment for persistent mild asthma. Effectiveness is to be reassessed at 3 months, and if it is insufficient the patient is no longer considered mildly asthmatic, and treatment has to be stepped up. As mild asthma is the most frequent form of the disease, diagnosis and management require physicians' particular attention.

Predictors of early hospital readmission for asthma among inner-city children

Factors associated with early asthma readmission have not been fully studied. To identify predictors of early readmission, we performed a matched case-control study of children discharged with primary diagnosis of asthma. Cases were readmitted with asthma within 30 days of discharge. Controls were not readmitted. Conditional logistic regression analysis was used. History of asthma hospitalization within the past 12 months was an independent predictor of early readmission (OR 1.89, p = 0.021). Modifiable factors such as medical treatment and management during and upon discharge from the index admission did not predict early asthma readmission.