Performance of the Acute Asthma Intensity Research Score (AAIRS) for acute asthma research protocols

Prospective Observational Study of Clinical Outcomes After Intravenous Magnesium for Moderate and Severe Acute Asthma Exacerbations in Children

BACKGROUND

There is limited knowledge regarding whether intravenous magnesium (IV-Mg) improves outcomes in children with acute asthma exacerbations.

OBJECTIVE

To examine whether IV-Mg improves outcomes in children with moderate and severe exacerbations.

METHODS

We performed a secondary analysis using data from a prospective observational cohort of children aged 5 to 17 years with moderate and severe exacerbations. Standardized treatment included systemic corticosteroid and inhaled albuterol, with consideration of IV-Mg (75 mg/kg) for patients with insufficient response after 20 minutes. Propensity score (PS) models were used to examine associations of IV-Mg treatment with change in the validated Acute Asthma Intensity Research Score, hospitalization rate, and time to spacing of inhaled albuterol of 4 hours or more among hospitalized participants.

RESULTS

Among 301 children, median (interquartile range) age was 8.1 (6.4-10.2) years, 170 were Black (57%), 201 were male (67%), and 84 received IV-Mg (28%). In a PS covariate-adjusted multivariable linear regression model, IV-Mg treatment was associated with a 2-hour increase in the Acute Asthma Intensity Research Score (β-coefficient = 0.98; 95% confidence interval [CI], 0.20-1.77), indicating increased exacerbation severity. Three additional PS-based models yielded similar results. Participants receiving IV-Mg had 5.8-fold (95% CI, 2.8-11.9) and 6.8-fold (95% CI, 3.6-12.9) greater odds of hospitalization in PS-based multivariable regression models. Among hospitalized participants, there was no difference in time to albuterol of every 4 hours or more in a PS covariate-adjusted Cox proportional hazards model (hazard ratio = 1.2; 95% CI, 0.8-1.8).

CONCLUSIONS

Among children with moderate and severe exacerbations, IV-Mg is associated with increased exacerbation severity, increased risk for hospitalization, and no acceleration in exacerbation resolution among hospitalized participants.

Nebulized albuterol delivery is associated with decreased skeletal muscle strength in comparison with metered-dose inhaler delivery among children with acute asthma exacerbations

OBJECTIVE

Albuterol is a β2-agonist and causes an intracellular shift of potassium from the interstitium. Whole-body hypokalemia is known to cause skeletal muscle weakness, but whether this occurs as a result of hypokalemia from the intracellular shift during albuterol treatment is unknown. We sought to determine if albuterol total dose or route of administration (nebulization and/or metered-dose inhaler) is associated with skeletal muscle weakness.

METHODS

This was a prospective observational study using convenience sampling. Skeletal muscle strength was measured before and after 1 hour of albuterol treatment using a hand-grip dynamometer in participants aged 5-17 years with acute asthma exacerbation in the emergency department. We examined associations of albuterol dose and route of administration with changes in grip strength.

RESULTS

Among 50 participants, 10 received continuous albuterol by nebulizer and 40 received albuterol by metered-dose inhaler. The median (interquartile range) in change of grip was -7.8% (interquartile range, -23.3, +5.1) for those treated with a nebulizer and +2.4% (interquartile range, -5%, +12.7%) for those treated with a metered-dose inhaler (P = 0.036 for the difference). In a multiple linear regression model adjusted for the pretreatment Acute Asthma Intensity Research Score and age, participants treated with a nebulizer had a 12.9% decrease in skeletal muscle strength compared with those treated with a metered-dose inhaler.

CONCLUSION

Higher doses of albuterol administered via nebulization result in decreased skeletal muscle strength in patients with acute asthma; whereas, albuterol administration via metered-dose inhalers showed no effect on skeletal muscle strength.

Validation of the Hospital Asthma Severity Score (HASS) in children ages 2-18 years old

INTRODUCTION

The Hospital Asthma Severity Score (HASS) was developed to communicate inpatient asthma severity between providers. The purpose of this prospective study was to validate the HASS against the Pediatric Respiratory Assessment Measure (PRAM) and spirometry for assessment of inpatient asthma exacerbation severity in patients 2-18 years old, at a single point-in-time.

METHODS

This study was registered with clinicaltrials.gov (NCT02782065). Children admitted to a tertiary care, free-standing children's hospital were assessed for asthma severity using the HASS, PRAM, and pulmonary function by spirometry. Inter-rater agreement of HASS and PRAM scores was assessed between two blinded clinician raters. Spirometry results were obtained by a certified pulmonary laboratory technician and correlated with HASS and PRAM scores.

RESULTS

The sample included 58 subjects. Allowing for a one-point difference in continuous HASS and PRAM scores, inter-rater agreement was 79% for the HASS and 60% for the PRAM. When the scores were categorized as mild, moderate, and severe, inter-rater agreement was 62% for the HASS and 93% for the PRAM (p < .0001). Additionally, intra-rater agreement between HASS and PRAM severity categories was 71% for Rater 1 and 64% for Rater 2. A weak correlation was noted between both the HASS and FEV₁ (r = -0.31; p = 0.11), and PRAM and FEV₁ (r = -0.30; p = 0.11) for the 29 subjects with acceptable spirometry results.

CONCLUSIONS

The HASS and PRAM have acceptable inter-rater and intra-rater agreement. These results support validation of the HASS for managing hospitalized patients during asthma exacerbations.

Pediatric acute asthma scoring systems: a systematic review and survey of UK practice

BACKGROUND

Acute exacerbations of asthma are common in children. Multiple asthma severity scores exist, but current emergency department (ED) use of severity scores is not known.

METHODS

A systematic review was undertaken to identify the parameters collected in pediatric asthma severity scores. A survey of Paediatric Emergency Research in the United Kingdom and Ireland (PERUKI) sites was undertaken to ascertain routinely collected asthma data and information about severity scores. Included studies examined severity of asthma exacerbation in children 5-18 years of age with extractable severity parameters.

RESULTS

Sixteen articles were eligible, containing 17 asthma severity scores. The severity scores assessed combinations of 15 different parameters (median, 6; range, 2-8). The most common parameters considered were expiratory wheeze (15/17), inspiratory wheeze (13/17), respiratory rate (10/17), and general accessory muscle use (9/17). Fifty-nine PERUKI centers responded to the questionnaire. Twenty centers (33.1%) currently assess severity, but few use a published score. The most commonly recorded routine data required for severity scores were oxygen saturations (59/59, 100%), heart rate, and respiratory rate (58/59, 98.3% for both). Among well-validated scores like the Pulmonary Index Score (PIS), Pediatric Asthma Severity Score (PASS), Childhood Asthma Score (CAS), and the Pediatric Respiratory Assessment Measure (PRAM), only 6/59 (10.2%), 3/59 (5.1%), 1/59 (1.7%), and 0 (0%) of units respectively routinely collect the data required to calculate them.

CONCLUSION

Standardized published pediatric asthma severity scores are infrequently used. Improved routine data collection focusing on the key parameters common to multiple scores could improve this, facilitating research and audit of pediatric acute asthma.

The effectiveness of magnesium sulfate for status asthmaticus outside the intensive care setting

AIM

Magnesium is an adjunctive therapy used in patients with status asthmaticus who do not respond to conventional therapy. The optimal time from initiation of therapy, to determination of response and administration of magnesium has not yet been resolved. Our objective was to determine if magnesium administered in the non-intensive care setting can decrease duration of continuous albuterol and hospital length of stay.

METHODS

We performed a retrospective cohort analysis of children ages 2-18 years admitted to the pediatric unit on continuous albuterol between January 2014 and December 2015 in a tertiary care children's hospital. Cohorts were matched on respiratory assessment score (RAS) obtained at a similar duration of albuterol therapy and evaluated for the total duration of continuous albuterol, length of stay (LOS), and adverse events.

RESULTS

Thirty-three patients who received magnesium were matched to 33 patients with the same RAS at a similar duration of continuous albuterol therapy who did not receive magnesium. Those who received magnesium had longer duration on continuous albuterol (34 vs 18 h; P = 0.001; 95% confidence interval [CI] 4-20; effect size 0.41) and longer LOS (72 vs 49 h; P = 0.037; 95% confidence interval [CI] 1-33; effect size 0.26) than those who did not receive magnesium.

CONCLUSION

Children requiring continuous albuterol for status asthmaticus can be administered magnesium sulfate outside the PICU with a low incidence of adverse events; however, among a RAS matched cohort, those who received magnesium did not experience shorter time on continuous albuterol, or hospital length of stay.

Adapting an Evidence-Based Pediatric Acute Asthma Exacerbation Severity Assessment Tool for Pediatric Primary Care

INTRODUCTION

The purposes of this project were (a) to examine criteria derived from evidence-based pediatric acute asthma exacerbation assessment tools, asthma scores, and the acute asthma prediction rule validated and used in the emergency department and (b) to adapt these criteria for pediatric primary care.

METHOD

The three stages of the project included (a) identification of criteria in a literature review, (b) validation of the criteria by an expert panel, and (c) adaptation of the criteria in the design of an assessment tool.

RESULTS

The criteria were validated and adapted in the design of The Pediatric Acute Asthma Exacerbation Severity Assessment and Disposition Decision-Making Tool for Pediatric Primary Care.

DISCUSSION

The adaptation of criteria derived from the evidence and validated by an expert panel will inform and guide clinicians in assessing severity and support decision making in determining disposition of pediatric patients presenting with an acute asthma exacerbation in primary care.

Clinical Utility of the Modified Pulmonary Index Score as an Objective Assessment Tool for Acute Asthma Exacerbation in Children

Introduction:

The Modified Pulmonary Index Score (MPIS) was developed as an objective assessment tool for acute asthma exacerbation in children. Although it is considered reliable, there are no known studies of its clinical utility. The objective of this study was to evaluate the validity of the MPIS for children with acute asthma in a clinical setting.

Methods:

In this retrospective study conducted between July 2009 and June 2011 using electronic medical records at the emergency department of a single pediatric medical center in Tokyo, Japan, the MPIS was recorded for patients with acute asthma at initial assessment and after treatment with an inhaled beta-agonist. We evaluated the responsiveness and predictive validity of the MPIS using disposition as an outcome.

Results:

A total of 2242 patients were assessed using the MPIS (median age, 3 years; 71.2% patients were 5 years or younger). The mean (SD) MPIS at initial assessment was 7.1 (3.6) and was significantly higher for the admission group than for the non-admission group (9.9 [2.9] vs. 5.9 [3.1]; P < 0.001). The receiver operator characteristic curve of the initial MPIS for hospital admission demonstrated moderate predictive ability (area under the curve, 0.83). An MPIS reduction of 3 or more indicated a clinically significant change when the MPIS at initial assessment was between 6 and 10 (risk ratio for admission [95% CI], 0.41 [0.28–0.60]; P < 0.001).

Conclusion:

The MPIS demonstrated good concurrent validity, predictive validity, and responsiveness in a wide range of clinical settings.

Clinical respiratory scales: which one should we use?

INTRODUCTION

There are countless clinical respiratory scales for acute dyspnoea. Most healthcare professionals choose one based on previous personal experience or following local practice, unaware of the implications of their choice. The lack of critical comparisons between those different tools has been a widespread problem that only recently has begun to be addressed via score validation studies. Here we try to assess and compare the quality criteria of measurement properties of acute dyspnoea scores. Areas covered: A literature review was conducted by searching the PubMed database. Forty-five documents were deemed eligible as they reported the use or building of clinical scales, using at least two parameters, and applied these to an acute episode of respiratory dyspnoea. Our primary focus was the description of the validity, reliability and utility of 41 suitable scoring instruments. Differences in sample selection, study design, rater profiles and potential methodological shortcomings were also addressed. Expert commentary: All acute dyspnoea scores lack complete validation. In particular, the areas of measurement error and interpretability have not been addressed correctly by any of the tools reviewed. Frequent modification of pre-existing scores (in items composition and/or name), differences in study design and discrepancies in reviewed sources also hinder the search for an adequate tool.

Direct concurrent comparison of multiple pediatric acute asthma scoring instruments

OBJECTIVE

Appropriate delivery of Emergency Department (ED) treatment to children with acute asthma requires clinician assessment of acute asthma severity. Various clinical scoring instruments exist to standardize assessment of acute asthma severity in the ED, but their selection remains arbitrary due to few published direct comparisons of their properties. Our objective was to test the feasibility of directly comparing properties of multiple scoring instruments in a pediatric ED.

METHODS

Using a novel approach supported by a composite data collection form, clinicians categorized elements of five scoring instruments before and after initial treatment for 48 patients 2-18 years of age with acute asthma seen at the ED of a tertiary care pediatric hospital ED from August to December 2014. Scoring instruments were compared for inter-rater reliability between clinician types and their ability to predict hospitalization.

RESULTS

Inter-rater reliability between clinician types was not different between instruments at any point and was lower (weighted kappa range 0.21-0.55) than values reported elsewhere. Predictive ability of most instruments for hospitalization was higher after treatment than before treatment (p < 0.05) and may vary between instruments after treatment (p = 0.054).

CONCLUSIONS

We demonstrate the feasibility of comparing multiple clinical scoring instruments simultaneously in ED clinical practice. Scoring instruments had higher predictive ability for hospitalization after treatment than before treatment and may differ in their predictive ability after initial treatment. Definitive conclusions about the best instrument or meaningful comparison between instruments will require a study with a larger sample size.

The asthma prediction rule to decrease hospitalizations for children with asthma

PURPOSE OF REVIEW

The aim of the present review was to discuss the challenges around clinical decision-making for hospitalization of children with acute asthma exacerbations and the development, internal validation, and future potential of the asthma prediction rule (APR) to provide meaningful clinical decision-support that might decrease unnecessary hospitalizations.

RECENT FINDINGS

The APR was developed and internally validated using predictor variables available before treatment in the emergency department, and performed well to predict 'need-for-hospitalization.' Oxygen saturation on room air and expiratory phase prolongation were most strongly associated with need-for-hospitalization.

SUMMARY

Research on prediction rules in pediatric asthma is rare. We developed and internally validated the APR using clinically intuitive predictor variables that are available at the bedside. Before incorporation into electronic decision-support the APR must undergo external validation and an impact analysis to determine if use of this tool will change clinician behavior and improve patient outcomes.

Pediatric acute asthma exacerbations: Evaluation and management from emergency department to intensive care unit

OBJECTIVE

The goal of this report is to review available modalities for assessing and managing acute asthma exacerbations in pediatric patients, including some that are not included in current expert panel guidelines. While it is not our purpose to provide a comprehensive review of the National Asthma Education and Prevention Program (NAEPP) guidelines, we review NAEPP-recommended treatments to provide the full range of treatments available for managing exacerbations with an emphasis on the continuum of care between the ER and ICU.

DATA SOURCES

We searched PubMed using the following search terms in different combinations: asthma, children, pediatric, exacerbation, epidemiology, pathophysiology, guidelines, treatment, management, oxygen, albuterol, β2-agonist, anticholinergic, theophylline, corticosteroid, magnesium, heliox, BiPAP, ventilation, mechanical ventilation, non-invasive mechanical ventilation and respiratory failure. We attempted to weigh the evidence using the hierarchy in which meta-analyses of randomized controlled trials (RCTs) provide the strongest evidence, followed by individual RCTs, followed by observational studies. We also reviewed the NAEPP and Global Initiative for Asthma expert panel guidelines.

RESULTS AND CONCLUSIONS

Asthma is the most common chronic disease of childhood, and acute exacerbations are a significant burden to patients and to public health. Optimal assessment and management of exacerbations, including appropriate escalation of interventions, are essential to minimize morbidity and prevent mortality. While inhaled albuterol and systemic corticosteroids are the mainstay of exacerbation management, escalation may include interventions discussed in this review.

Pulse Oximeter Plethysmograph Estimate of Pulsus Paradoxus as a Measure of Acute Asthma Exacerbation Severity and Response to Treatment

OBJECTIVES

Pulsus paradoxus is one of the few objective bedside measures of acute asthma exacerbation severity but is difficult to measure in tachypneic and tachycardic patients and in noisy clinical environments. Our primary objective was to examine whether pulse oximeter plethysmograph estimate of pulsus paradoxus (PEP) is associated with physiologic and symptom measures of acute exacerbation severity (airway resistance by impulse oscillometry [%IOS] and the Acute Asthma Intensity Research Score [AAIRS]). Secondary objectives were to validate the previous association of PEP with percent predicted forced expiratory volume in 1 second (%FEV1 ) and to examine associations of change of PEP with change of these outcomes after 2 hours of treatment.

METHODS

This was a secondary analysis of data from a prospective observational study of patients aged 5-17 years with acute asthma exacerbations. The predictor variable, PEP, was measured using a dedicated pulse oximeter and waveform analysis program. Outcome measures included the AAIRS, %IOS, and %FEV1 at baseline and after 2 hours of treatment. We examined associations of PEP with %IOS and the AAIRS at baseline using multiple linear regression models adjusted for age, sex, and race. As secondary analyses we similarly examined the association of PEP with %FEV1 at baseline and change of PEP with change of %IOS, the AAIRS, and %FEV1 after 2 hours of treatment using multiple linear regression models adjusted for the baseline value of the outcome measure and the AAIRS.

RESULTS

Among 684 participants (61% males; 61% African American) there were associations of baseline PEP with %IOS, the AAIRS, and %FEV1 (p < 0.001). Change of PEP after 2 hours of treatment was associated with change of %FEV1 (p < 0.001) and change of the AAIRS (p = 0.01) but not with change of %IOS (p = 0.60).

CONCLUSIONS

PEP demonstrates criterion validity in predicting baseline %IOS, the AAIRS, and %FEV1 , and responsiveness to change of the AAIRS and %FEV1 . Data contained in the oximeter plethysmograph waveform might be utilized as a continuous, objective measure of acute asthma exacerbation severity and real-time response to treatment.

Development and internal validation of a pediatric acute asthma prediction rule for hospitalization

BACKGROUND

Clinicians have difficulty predicting need for hospitalization of children with acute asthma exacerbations.

OBJECTIVE

The objective of this study was to develop and internally validate a multivariable asthma prediction rule (APR) to inform hospitalization decision making in children aged 5-17 years with acute asthma exacerbations.

METHODS

Between April 2008 and February 2013 we enrolled a prospective cohort of patients aged 5-17 years with asthma who presented to our pediatric emergency department with acute exacerbations. Predictors for APR modeling included 15 demographic characteristics, asthma chronic control measures, and pulmonary examination findings in participants at the time of triage and before treatment. The primary outcome variable for APR modeling was need for hospitalization (length of stay >24 h for those admitted to hospital or relapse for those discharged). A secondary outcome was the hospitalization decision of the clinical team. We used penalized maximum likelihood multiple logistic regression modeling to examine the adjusted association of each predictor variable with the outcome. Backward step-down variable selection techniques were used to yield reduced-form models.

RESULTS

Data from 928 of 933 participants were used for prediction rule modeling, with median [interquartile range] age 8.8 [6.9, 11.2] years, 61% male, and 59% African-American race. Both full (penalized) and reduced-form models for each outcome calibrated well, with bootstrap-corrected c-indices of 0.74 and 0.73 for need for hospitalization and 0.81 in each case for hospitalization decision.

CONCLUSION

The APR predicts the need for hospitalization of children with acute asthma exacerbations using predictor variables available at the time of presentation to an emergency department.