Clinical scores for acute asthma in pre-school children. A review of the literature

Pulse oximetry respiratory monitoring for assessment of acute childhood wheeze

OBJECTIVE

There is a lack of objective measures to assess children with acute wheezing episodes. Increased respiratory rate (RR) and pulsus paradoxus (PP) are recognised markers, but poorly recorded in practice. We examined whether they can be reliably assessed from a pulse oximeter plethysmogram ('pleth') trace and predict clinical outcome.

PATIENTS AND METHODS

We studied 44 children aged 1-7 years attending hospital with acute wheeze, following initial 'burst' bronchodilator therapy (BT), and used custom software to measure RR and assess PP from oximeter pleth traces. Traces were examined for quality, and the accuracy of the RR measurement was validated against simultaneous respiratory inductive plethysmography (RIP). RR and PP at 1 hour after BT were compared with clinical outcomes.

RESULTS

RR from pleth and RIP showed excellent agreement, with a mean difference (RIP minus pleth) of -0.5 breaths per minute (limits of agreement -3.4 to +2.3). 52% of 1 min epochs contained 10 s or more of pleth artefact. At 1 hour after BT, children who subsequently required intravenous bronchodilators had significantly higher RR (median (IQR) 63 (62-66) vs 43 (37-51) breaths per minute) than those who did not, but their heart rate and oxygen saturation were similar. Children with RR ≥55 per minute spent longer in hospital: median (IQR) 30 (22-45) vs 10 (7-21) hours. All children who subsequently required hospital admission had PP-analogous pleth waveforms 1 hour after BT.

CONCLUSION

RR can be reliably measured and PP detected from the pulse oximeter pleth trace in children with acute wheeze and both markers predict clinical outcome.

TRIAL REGISTRATION NUMBER

UKCRN15742.

Development of a pediatric asthma predictive index for hospitalization

BACKGROUND

Variation in emergency department (ED) management for asthma exacerbation leads to disparities in care. Current asthma severity scores are insufficient to be used for hospitalization decisions.

OBJECTIVE

To develop and internally validate an asthma predictive index for hospitalization (APIH) to guide practitioners in their admission decision for children with asthma exacerbations.

METHODS

Data were collected from 12,066 children between 5 and 18 years old diagnosed with asthma exacerbation in the ED. Epidemiologic findings, number of inhaled corticosteroid canisters, short-acting β-blocker canisters, oral steroids, coexisting atopy, family history of atopy, insurance, and prior asthma ED visits or hospitalizations were compared between patients hospitalized and discharged. We used univariate analysis and multivariate analysis to determine the best predictor variables for hospitalization. Our study internally validated the prediction index to estimate future performance of the prediction rule.

RESULTS

The highest risk factors associated with asthma hospitalization from the ED are oxygen saturation less than 94%, respiratory rate greater than 31/min, history of pneumonia, and asthma ED visits in past 12 months. With a reduced predictive model that combined these risk factors, the odds ratio was 44.9 (95% CI, 32.8-61.4), which is extremely significant. Our C index of discrimination of 0.77 was similar to the validation C index of 0.78, which confirms a solid prediction model.

CONCLUSION

We have developed and internally validated a pediatric hospitalization prediction index for acute asthma exacerbation in the ED. Further studies are needed to externally validate the APIH before its implementation into clinical practice.

The clinical respiratory score predicts paediatric critical care disposition in children with respiratory distress presenting to the emergency department

Background

Respiratory distress is a common presenting complaint in children brought to the Emergency Department (ED). The Clinical Respiratory Score (CRS) has shown promise as a screen for severe illness in High Income Countries. We aimed to validate the admission CRS in children presenting to the ED of a Low-to Middle Income Country.

Methods

Children (1 month to 16 years) presenting with respiratory distress to the ED of the Aga Khan University Hospital, Karachi, Pakistan, between November 2015 to March 2016, were enrolled. The CRS was measured at initial presentation, prior to any management and 2 h after treatment was started. The predictive value for admission to the paediatric critical care units for a variety of cut offs for CRS at presentation were derived.

Results

A total of 112 children (70% male) of median age 12 months (IQR 2, 34.5 months) were enrolled. Patients with severe CRS (score 8–12) at presentation were more likely to be admitted to paediatric critical care (90% vs. 23% with mild-moderate CRS; OR: 5.7; 95% CI: 2.2–15.3, p < 0.001). The sensitivity and specificity of CRS > 3 in predicting outcome were 94% (95% CI 79.8–99.3) and 40% (95% CI 35–45), respectively, with a positive likelihood ratio of 1.6 (95% CI 1.31–1.98) and negative predictive value of 94% (95% CI 81–98).

Conclusion

An admission CRS of > 3 in the ED of a Low-to Middle Income Country had excellent predictive value for disease severity, and it should be considered for incorporation into ED triage protocols.

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.

Initial Asthma Severity Assessment Tools as Predictors of Hospitalization

BACKGROUND

Assessment tools to classify and prioritize patients, such as systems of triage, and indicators of severity, such as clinical respiratory scores, are helpful in guiding the flow of asthmatic patients in the emergency department.

OBJECTIVE

Our aim was to assess the performance of the Pediatric Assessment Triangle (PAT), triage level (TL), Pulmonary Score (PS), and initial O₂ saturation (O₂ sat), in predicting hospitalization in pediatric acute asthma exacerbations.

STUDY DESIGN

Retrospective study evaluating PAT, TL, and PS at presentation, and initial O₂ sat of asthmatic children in the pediatric emergency department (PED). The primary outcome measure was the rate of hospitalization. Secondary outcomes were length of stay (LOS) in the PED and admission to the pediatric intensive care unit (PICU).

RESULTS

PAT, TL, PS, and initial O₂ sat were recorded in 14,953 asthmatic children. Multivariate analysis yielded the following results: Abnormal PAT and more severe TLs (I-II) were independent risk factors for hospitalization (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.4-1.8; OR 3.4, 95% CI 2.6-4.3, respectively) and longer LOS (OR 1.5, 95% CI 1.3-1.7; OR 2.6, 95% CI 2-3.3, respectively). PS > 3 showed a strong association with hospitalization (OR 8.1, 95% CI 7-9.4), PICU admission (OR 9.6, 95% CI 3-30.9) and longer LOS (OR 6.2, 95% CI 5.6-6.9). O₂ sat < 94% was an independent predictor of admission (OR 5.2, 95% CI 4.6-5.9), PICU admission (OR 4.6, 95% CI 4.5-4.6), and longer LOS (OR 4.6, 95% CI 4.1-5.2).

CONCLUSIONS

PAT, TL, PS, and initial O₂ sat are good predictors of hospitalization in pediatric acute asthma exacerbations.

Clinical Scores for Dyspnoea Severity in Children: A Prospective Validation Study

BACKGROUND

In acute dyspnoeic children, assessment of dyspnoea severity and treatment response is frequently based on clinical dyspnoea scores. Our study aim was to validate five commonly used paediatric dyspnoea scores.

METHODS

Fifty children aged 0-8 years with acute dyspnoea were clinically assessed before and after bronchodilator treatment, a subset of 27 children were videotaped and assessed twice by nine observers. The observers scored clinical signs necessary to calculate the Asthma Score (AS), Asthma Severity Score (ASS), Clinical Asthma Evaluation Score 2 (CAES-2), Pediatric Respiratory Assessment Measure (PRAM) and respiratory rate, accessory muscle use, decreased breath sounds (RAD).

RESULTS

A total of 1120 observations were used to assess fourteen measurement properties within domains of validity, reliability and utility. All five dyspnoea scores showed overall poor results, scoring insufficiently on more than half of the quality criteria for measurement properties. The AS and PRAM were the most valid with good values on six and moderate values on three properties. Poor results were mainly due to insufficient measurement properties in the validity and reliability domains whereas utility properties were moderate to good in all scores.

CONCLUSION

This study shows that commonly used dyspnoea scores show insufficient validity and reliability to allow for clinical use without caution.

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.

Validity of bronchiolitis outcome measures

BACKGROUND

The Respiratory Distress Assessment Instrument (RDAI) and Respiratory Assessment Change Score (RACS) are frequently used in bronchiolitis clinical trials, but evidence is limited on their measurement properties. We investigated their validity, reliability, and responsiveness.

METHODS

We included data from up to 1765 infants with bronchiolitis enrolled in 2 studies conducted in pediatric emergency departments. We assessed RDAI construct validity by testing hypotheses of associations with physiologic measures (respiratory rate, oxygen saturation) and with constructs related to hospitalization, using correlation coefficients, and multivariable analysis. RDAI/RACS responsiveness was evaluated by using anchors of change based on these constructs; measures of responsiveness included the area under the curve. RDAI test-retest agreement and interrater reliability were evaluated by using limits of agreement and intraclass correlation coefficients.

RESULTS

Baseline RDAI scores were weakly correlated with respiratory rate (r = 0.38, P < .001), and scores increased in lower oxygen saturation categories (P < .001). Higher RDAI scores were associated with hospitalization (odds ratio: 1.36; 95% confidence interval: 1.26-1.47); scores differed between participants who were discharged, admitted, or stayed in the emergency department (P < .001). Our hypotheses were met, but the magnitude of associations was below our predefined thresholds. RDAI test-retest limits of agreement were -3.80 to 3.64 (20% of the range), whereas interrater reliability was good (intraclass correlation coefficient = 0.93). Formulated hypotheses for responsiveness were confirmed, with moderate responsiveness (area under the curve: RDAI, 0.64-0.70; RACS, 0.72).

CONCLUSIONS

RDAI has poor to moderate construct validity, with good discriminative properties but considerable test-retest measurement error. The RDAI and RACS are responsive measures of respiratory distress in bronchiolitis but do not encompass all determinants of disease severity.

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.

Modified pulmonary index score was sufficiently reliable to assess the severity of acute asthma exacerbations in children

BACKGROUND

The Modified Pulmonary Index Score (MPIS) was developed as an indicator of the severity of acute asthma in children. The objective of this study is to evaluate the reliability and validity of the MPIS for children with acute asthma, including those five years or younger in age.

METHODS

We evaluated the inter-rater reliability and internal consistency of the MPIS by having at least two trained physicians and a nurse-each of whom was blinded to the others' scores-simultaneously examine inpatients with asthma exacerbation and rate them according to the MPIS. We also evaluated the intraclass correlation coefficient (ICC), kappa, Cronbach's α and correlations between the MPIS and other indicators associated with asthma severity.

RESULTS

A total of 25 children (median age, five years; 13 patients were five years or younger in age) were enrolled in this study. The MPIS showed excellent inter-rater reliability (all ages: ICC = 0.95, 95% CI = 0.94-0.97; five years or younger: ICC = 0.93, 95% CI = 0.89-0.96) and good internal consistency (all ages: Cronbach's α = 0.87; five years or younger: Cronbach's α = 0.85). The MPIS showed good correlation with a visual analogue scale assessed by the physicians.

CONCLUSIONS

The MPIS was a sufficiently reliable assessment tool for children with acute asthma, including those five years or younger in age.

Systematic review: insufficient validation of clinical scores for the assessment of acute dyspnoea in wheezing children

BACKGROUND

A reliable, valid, and easy-to-use assessment of the degree of wheeze-associated dyspnoea is important to provide individualised treatment for children with acute asthma, wheeze or bronchiolitis.

OBJECTIVE

To assess validity, reliability, and utility of all available paediatric dyspnoea scores.

METHODS

Systematic review. We searched Pubmed, Cochrane library, National Guideline Clearinghouse, Embase and Cinahl for eligible studies. We included studies describing the development or use of a score, assessing two or more clinical symptoms and signs, for the assessment of severity of dyspnoea in an acute episode of acute asthma, wheeze or bronchiolitis in children aged 0-18 years. We assessed validity, reliability and utility of the retrieved dyspnoea scores using 15 quality criteria.

RESULTS

We selected 60 articles describing 36 dyspnoea scores. Fourteen scores were judged unsuitable for clinical use, because of insufficient face validity, use of items unsuitable for children, difficult scoring system or because complex auscultative skills are needed, leaving 22 possibly useful scores. The median number of quality criteria that could be assessed was 7 (range 6-11). The median number of positively rated quality criteria was 3 (range 1-5). Although most scores were easy to use, important deficits were noted in all scores across the three methodological quality domains, in particular relating to reliability and responsiveness.

CONCLUSION

None of the many dyspnoea scores has been sufficiently validated to allow for clinically meaningful use in children with acute dyspnoea or wheeze. Proper validation of existing scores is warranted to allow paediatric professionals to make a well balanced decision on the use of the dyspnoea score most suitable for their specific purpose.

Severe acute asthma exacerbation in children: a stepwise approach for escalating therapy in a pediatric intensive care unit

OBJECTIVES

An increasing prevalence of pediatric asthma has led to increasing burdens of critical illness in children with severe acute asthma exacerbations, often leading to respiratory distress, progressive hypoxia, and respiratory failure. We review the definitions, epidemiology, pathophysiology, and clinical manifestations of severe acute asthma, with a view to developing an evidence-based, stepwise approach for escalating therapy in these patients.

METHODS

Subject headings related to asthma, status asthmaticus, critical asthma, and drug therapy were used in a MEDLINE search (1980-2012), supplemented by a manual search of personal files, references cited in the reviewed articles, and treatment algorithms developed within Le Bonheur Children's Hospital.

RESULTS

Patients with asthma require continuous monitoring of their cardiorespiratory status via noninvasive or invasive devices, with serial clinical examinations, objective scoring of asthma severity (using an objective pediatric asthma score), and appropriate diagnostic tests. All patients are treated with β-agonists, ipratropium, and steroids (intravenous preferable over oral preparations). Patients with worsening clinical status should be progressively treated with continuous β-agonists, intravenous magnesium, helium-oxygen mixtures, intravenous terbutaline and/or aminophylline, coupled with high-flow oxygen and non-invasive ventilation to limit the work of breathing, hypoxemia, and possibly hypercarbia. Sedation with low-dose ketamine (with or without benzodiazepines) infusions may allow better toleration of non-invasive ventilation and may also prepare the patient for tracheal intubation and mechanical ventilation, if indicated by a worsening clinical status.

CONCLUSIONS

Severe asthma can be a devastating illness in children, but most patients can be managed by using serial objective assessments and the stepwise clinical approach outlined herein. Following multidisciplinary education and training, this approach was successfully implemented in a tertiary-care, metropolitan children's hospital.

Pediatric status asthmaticus

Status asthmaticus is a frequent cause of admission to a pediatric intensive care unit. Prompt assessment and aggressive treatment are critical. First-line or conventional treatment includes supplemental oxygen, aerosolized albuterol, and corticosteroids. There are several second-line treatments available; however, few comparative studies have been performed and in the absence of good evidence-based treatments, the use of these therapies is highly variable and dependent on local practice and provider preference. In this article the pathophysiology and treatment of status asthmaticus is discussed, and the literature regarding second-line treatments is critically assessed to apply an evidence basis to the treatment of this severe disease.

Portable spirometry during acute exacerbations of asthma in children

BACKGROUND

Spirometry is the gold standard for assessment of asthma and is objective and non-invasive. This is a pilot study to evaluate whether portable spirometry can be successfully performed by children in the pediatric emergency department for acute exacerbations of asthma.

METHODS

We enrolled children more than 6 years of age presenting to an urban pediatric emergency department with a history of asthma during an acute exacerbation. On arrival and after each bronchodilator treatment, vital signs and a clinical score were recorded. Portable spirometry was then performed. Attempts were continued until acceptable and reproducible measurements were obtained or until the patient was unable to perform further attempts. Outcomes included success at spirometry and correlation of spirometry with clinical signs.

RESULTS

Thirty-four subjects were enrolled with a median age of 12 years. Ninety-one percent of subjects completed at least one attempt at spirometry. Seventy-three percent of all spirometry attempts were reproducible. Portable spirometry demonstrated increased severity of the exacerbation in comparison to clinical signs and peak expiratory flow. Percent of predicted forced expiratory volume in 1 second, ratio of forced expiratory volume in 1 second to forced vital capacity, and peak expiratory flow are all poorly correlated with degree of wheezing, clinical score, respiratory rate, and oxygen saturation (r < 0.5).

CONCLUSION

Portable spirometry can be successfully performed by children with acute exacerbations of asthma in the emergency department and demonstrated greater degrees of airway obstruction than did clinical signs. Spirometry provides objective, non-invasive measurements of the severity of airway obstruction in the emergency department for children with acute exacerbations of asthma.

A tree-based decision model to support prediction of the severity of asthma exacerbations in children

This paper describes the development of a tree-based decision model to predict the severity of pediatric asthma exacerbations in the emergency department (ED) at 2 h following triage. The model was constructed from retrospective patient data abstracted from the ED charts. The original data was preprocessed to eliminate questionable patient records and to normalize values of age-dependent clinical attributes. The model uses attributes routinely collected in the ED and provides predictions even for incomplete observations. Its performance was verified on independent validating data (split-sample validation) where it demonstrated AUC (area under ROC curve) of 0.83, sensitivity of 84%, specificity of 71% and the Brier score of 0.18. The model is intended to supplement an asthma clinical practice guideline, however, it can be also used as a stand-alone decision tool.

Evaluation of the methodological quality of systematic reviews of health status measurement instruments

A systematic review of measurement properties of health-status instruments is a tool for evaluating the quality of instruments. Our aim was to appraise the quality of the review process, to describe how authors assess the methodological quality of primary studies of measurement properties, and to describe how authors evaluate results of the studies. Literature searches were performed in three databases. One hundred and forty-eight reviews were included. The purpose of included reviews was to identify health status instruments used in an evaluative application and to report on the measurement properties of these instruments. Two independent reviewers selected the articles and extracted the data. Reviews were often of low quality: 22% of the reviews used one database, the search strategy was often poorly described, and in many cases it was not reported whether article selection (75%) and data extraction (71%) was done by two independent reviewers. In 11 reviews the methodological quality of the primary studies was evaluated for all measurement properties, and of these 11 reviews only 7 evaluated the results. Methods to evaluate the quality of the primary studies and the results differed widely. The poor quality of reviews hampers evidence-based selection of instruments. Guidelines for conducting and reporting systematic reviews of measurement properties should be developed.

The Pediatric Respiratory Assessment Measure: a valid clinical score for assessing acute asthma severity from toddlers to teenagers

OBJECTIVE

To determine the performance characteristics of the Preschool Respiratory Assessment Measure (PRAM) in preschool and school-aged children with acute asthma.

STUDY DESIGN

In a prospective cohort study, we examined the validity, responsiveness, and reliability of the PRAM in children aged 2 to 17 years with acute asthma. The study involved more than 100 nurses and physicians who recorded the PRAM on triage, after initial bronchodilation, and at disposition. Predictive validity and responsiveness were examined using disposition as outcome.

RESULTS

The PRAM was recorded in 81% (n = 782) of patients at triage. The PRAM at triage and after initial bronchodilation showed a strong association with admission (r = 0.4 and 0.5, respectively; P < .0001), thus supporting its ability to distinguish across severity levels. The responsiveness coefficient of 0.7 indicated good ability to identify change after bronchodilation. The PRAM showed good internal consistency (Cronbach alpha = 0.71) and inter-rater reliability (r = 0.78) for all patients and across all age groups.

CONCLUSIONS

Good performance characteristics were observed in all age groups, making the PRAM an attractive score for assessing asthma severity and response to treatment.

Correlations between pulse oximetry and peak expiratory flow in acute asthma

Few studies are available concerning correlations between pulse oximetry and peak expiratory flow in children and adolescents with acute asthma. Although the Global Initiative for Asthma states that measurements of lung function and oximetry are critical for the assessment of patients, it is not clear if both methods should necessarily be included in their evaluation. Since there is a significant difference in cost between pulse oximetry equipment and peak expiratory flow devices, we determined whether clinical findings and peak expiratory flow measurements are sufficient to determine the severity of acute asthma. The present prospective observational study was carried out to determine if there is correlation between pulse oximetry and peak expiratory flow determination in 196 patients with acute asthma aged 4 to 15 years diagnosed according to the Global Initiative for Asthma criteria. Patients experiencing their first or second wheezing episode, with fever, related acute or chronic diseases, and unable to perform the peak expiratory flow maneuver were excluded. Measurements of peak expiratory flow and pulse oximetry were performed at admission and after 15 min of each inhaled salbutamol cycle. Correlations obtained by linear regression using the Pearson correlation coefficients (r) were 0.41 (P < 0.0001), 0.53 (P < 0.0001), 0.51 (P < 0.0001), and 0.61 (P < 0.0001) at admission and after the first, second and third cycles of salbutamol, respectively. These correlations showed that one measure cannot substitute the other (Pearson's coefficient <0.7), probably because they evaluate different aspects in the airways, suggesting that peak expiratory flow should not be used alone in the assessment of acute asthma in children and adolescents.

Effect of a clinical pathway on the hospitalisation rates of children with asthma: a prospective study

AIM

To determine the effect of implementing a clinical pathway, using evidence-based clinical practice guidelines, for the emergency care of children and adolescents with asthma.

METHODS

A prospective, before-after, controlled trial was conducted, which included patients aged 1-18 years who had acute exacerbations of asthma treated in a tertiary care paediatric emergency department. Data were collected for identical 2-month seasonal periods before and after implementation of the clinical pathway to determine hospitalisation rate and other outcomes. For 2 weeks after emergency visits, the rate at which patients returned to emergency care for worsening asthma was evaluated. A multidisciplinary panel, using national guidelines and a systematic review, developed the pathway.

RESULTS

267 patients were studied. The rate of hospitalisation was significantly lower in the post-implementation group (10/74; 13.5%) than in the pre-implementation control group (53/193; 27.5%; p = 0.02; number needed to treat 7.1). All reduction in hospitalisation occurred in children with moderate to severe asthma exacerbation. After implementation of the clinical pathway, the rate of administration of oral corticosteroids to patients with moderate or severe exacerbations increased from 71% to 92% (p = 0.01), and significantly more patients received beta2-agonists in the first hour (p = 0.02). No significant change in relapse to acute care occurred within 2 weeks (p = 0.19).

CONCLUSIONS

An evidence-based clinical pathway for children and adolescents with moderate to severe exacerbations of acute asthma markedly decreases their rate of hospitalisation without increased return to emergency care.

Current management of status asthmaticus in the pediatric ICU

Status asthmaticus (SA) in the pediatric ICU (PICU) can progress to a life-threatening emergency. The goal of management is to improve hypoxemia, improve bronchoconstriction, and decrease airway edema through the administration of continuous nebulized beta2 adrenergic agonist with intermittent anticholinergics, corticosteroids, and oxygen. Adjunctive therapies, such as magnesium, methylxanthines, intravenous beta-agonists, heliox, and noninvasive ventilation should be considered in the child who fails to respond to initial therapies. The restoration of adequate pulmonary functions, resolution of airway obstruction, and avoidance of mechanical ventilation should guide management. This article reviews the pathophysiology, assessment, and management of the child who has SA in the PICU to provide the critical care nurse with current information to facilitate optimal care.

Electromyographic monitoring of respiratory muscle activity in dyspneic infants and toddlers

The aim of this study was to investigate whether the changes that occurred in the clinical asthma score (CAS) correlated with the changes in the respiratory electromyographic (EMG) activity over the days during admission to hospital in dyspneic infants and toddlers. Sixteen infants and toddlers (9 males) were studied during admission and 7 days after discharge. The CAS was used to assess the severity of dyspnea and consists of five items: respiration rate, wheezing, retractions, observed dyspnea, and inspiration-to-expiration ratio. Each item was scaled 0, 1, or 2, with a maximum score of 10. Electrical activity from the diaphragm (di) and intercostal muscles (int) was derived from surface electrodes. The logarithm of the EMG-Activity-Ratio (log EMGAR; ratio of mean peak-to-bottom EMG activity during admission to the hospital, to that at baseline, 7 days after discharge) was used as EMG parameter. For assessing the association between the repeated observations of the CAS and the EMG measurements we used the quantity r2 obtained with analysis of covariance. On the day of admission the patients had a mean CAS of 5.9 +/- 1.2. On the day of discharge the mean CAS decreased significantly to 2.1 +/- 1.6, indicating that the CAS returned to normal values. In line with this observation, a significant decrease in the log EMGARdi and log EMGARint was observed during the stay in the hospital. Over all subjects the correlation coefficient (r) of log EMGARdi versus CAS was 0.71, log EMGARint versus CAS was 0.67, and the mean log EMGAR versus CAS was 0.75 (p < 0.01, for all values). The correlation coefficients of subjects of < or = 1 year seemed to be lower than those of subjects of > 1 year of age (p < 0.01) and female subjects showed higher correlation coefficients than males. This study showed a moderate, but significant, relationship between the changes that occurred in the CAS and the changes in respiratory EMG activity during admission to hospital in dyspneic infants and toddlers. Moreover, the correlation coefficients of the combined leads of the intercostals and diaphragm (mean log EMGAR) were higher than those of the separate leads. The EMG measurements would extend diagnostic possibilities and would provide an objective measure to evaluate the clinical course of the disease and the efficacy of therapy in infants and toddlers with recurrent wheezing disorders.

A modified pulmonary index score with predictive value for pediatric asthma exacerbations

BACKGROUND

Several clinical asthma scores have been derived from combinations of physical findings in pediatric asthmatic patients.

OBJECTIVE

To test the reproducibility and validity of one such score, the Modified Pulmonary Index Score (MPIS), and to evaluate its predictive value in children hospitalized for asthma.

METHODS

In the MPIS, 6 categories are evaluated: oxygen saturation, accessory muscle use, inspiratory to expiratory flow ratio, degree of wheezing, heart rate, and respiratory rate. For each of these 6 measurements or observations, a score of 0 to 3 is assigned. To evaluate the reproducibility of the MPIS, inpatients with status asthmaticus were examined by an attending physician, nurse, and respiratory therapist who were blinded to the other observers' scores. To evaluate the validity of the MPIS as a scale of severity of illness in asthmatic patients, the score at admission was compared with selected outcomes in the same patients.

RESULTS

A total of 30 patients participated in this study (mean +/- SD age, 7.6 +/- 5.5 years). Our finding revealed that the MPIS is highly reproducible with a high degree of interrater reliability across caregiver groups (physician to nurse: r = 0.98; 95% confidence interval [CI], >0.96; physician to respiratory therapist: r = 0.95; 95% CI, >0.92; nurse to respiratory therapist: r = 0.94; 95% CI, >0.90). The admission MPIS positively correlated with intensive care unit admission (P < .001), days of continuous albuterol therapy (P = .002), days of supplemental oxygen (P = .002), and length of hospital stay (P = .004).

CONCLUSIONS

The MPIS is a highly reproducible and valid indicator of severity of illness in children with asthma. To our knowledge, this is the first pediatric clinical asthma score demonstrated to be reproducible across groups of health care professionals who treat pediatric patients with asthma.

Asthma severity scores for preschoolers displayed weaknesses in reliability, validity, and responsiveness

OBJECTIVE

To evaluate the measurement properties of asthma severity scores for use in preschool children.

METHODS

A Medline search was used to identify published asthma severity scores for use in preschool children. The measurement properties of the scores (item development, reliability, validity, responsiveness, and usability) were evaluated using a published framework.

RESULTS

Ten asthma severity scores were identified, with 19 different clinical variables used as items. Interrater agreement was assessed by five scores. Only two scores--Clinical Asthma Score (CAS) and Respiratory Distress Assessment Index (RDAI)--reported good agreement based on weighted kappa-statistics (0.64-0.90). Construct validity was reported by the CAS, Clinical Asthma Evaluation Score (CAES), the Clinical Symptom Grading System (CSGS), and the Preschool Respiratory Assessment Measure (PRAM). Correlation coefficients between asthma severity scores and clinical measures (length of stay, drug dosing interval, O2 saturation, health professional assessment, PaO2, PaCO2) ranged from 0.47 to 0.70. Responsiveness was formally demonstrated for two scales (PRAM, CAS).

CONCLUSIONS

Most asthma severity scales for use in preschool children have been informally developed. Recently developed scores (CAS, PRAM) have more rigorously evaluated their measurement properties. Research is needed to directly compare the asthma severity scores developed for use in preschool children.

Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma

OBJECTIVES

To evaluate the reliability, validity, and responsiveness of a new clinical asthma score, the Pediatric Asthma Severity Score (PASS), in children aged 1 through 18 years in an acute clinical setting.

METHODS

This was a prospective cohort study of children treated for acute asthma at two urban pediatric emergency departments (EDs). A total of 852 patients were enrolled at one site and 369 at the second site. Clinical findings were assessed at the start of the ED visit, after one hour of treatment, and at the time of disposition. Peak expiratory flow rate (PEFR) (for patients aged 6 years and older) and pulse oximetry were also measured.

RESULTS

Composite scores including three, four, or five clinical findings were evaluated, and the three-item score (wheezing, prolonged expiration, and work of breathing) was selected as the PASS. Interobserver reliability for the PASS was good to excellent (kappa = 0.72 to 0.83). There was a significant correlation between PASS and PEFR (r = 0.27 to 0.37) and pulse oximetry (r = 0.29 to 0.41) at various time points. The PASS was able to discriminate between those patients who did and did not require hospitalization, with area under the receiver operating characteristic curve of 0.82. Finally, the PASS was shown to be responsive, with a 48% relative increase in score from start to end of treatment and an overall effect size of 0.62, indicating a moderate to large effect.

CONCLUSIONS

This clinical score, the PASS, based on three clinical findings, is a reliable and valid measure of asthma severity in children and shows both discriminative and responsive properties. The PASS may be a useful tool to assess acute asthma severity for clinical and research purposes.

Use of a respiratory clinical score among different providers

Respiratory assessment of children with asthma or bronchiolitis is problematic because both the components of the assessment and their relative importance vary among care providers. Use of a systematic standard assessment process and clinical score may reduce interobserver variation. Our objective was to determine observer agreement among physicians (MD), nurses (RN), and respiratory therapists (RT), using a standard respiratory clinical score. A clinical score was developed incorporating four physiologic parameters: respiratory rate, retractions, dyspnea, and auscultation. One hundred and sixty-five provider pairs (e.g., MD-MD, RN-RT) independently assessed a total of 55 patients admitted for asthma, bronchiolitis, or wheezing at an urban tertiary-care hospital. A weighted kappa statistic measured agreement beyond chance. Rater pairs had high observed agreement on total score of 82-88% and weighted kappas ranging from 0.52 (MD-RN; 95% CI, 0.19, 0.79) to 0.65 (RN-RN; 95% CI, 0.46, 0.87). Observed agreement on individual components of the score ranged from 58% (auscultation) to 74% (dyspnea), with unweighted kappas of 0.36 (respiratory rate; 95% CI, 0.26, 0.46) to 0.53 (dyspnea; 95% CI, 0.41, 0.65). In conclusion, this respiratory clinical score demonstrates good interobserver agreement between MDs, RNs, and RTs. Future research is needed to examine validity and responsiveness in clinical settings. By standardizing respiratory assessments, use of a clinical score may facilitate care coordination by physicians, nurses, and respiratory therapists and thereby improve care of children hospitalized with asthma and bronchiolitis.

Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma

OBJECTIVES

To evaluate the reliability, validity, and responsiveness of a new clinical asthma score, the Pediatric Asthma Severity Score (PASS), in children aged 1 through 18 years in an acute clinical setting.

METHODS

This was a prospective cohort study of children treated for acute asthma at two urban pediatric emergency departments (EDs). A total of 852 patients were enrolled at one site and 369 at the second site. Clinical findings were assessed at the start of the ED visit, after one hour of treatment, and at the time of disposition. Peak expiratory flow rate (PEFR) (for patients aged 6 years and older) and pulse oximetry were also measured.

RESULTS

Composite scores including three, four, or five clinical findings were evaluated, and the three-item score (wheezing, prolonged expiration, and work of breathing) was selected as the PASS. Interobserver reliability for the PASS was good to excellent (kappa = 0.72 to 0.83). There was a significant correlation between PASS and PEFR (r = 0.27 to 0.37) and pulse oximetry (r = 0.29 to 0.41) at various time points. The PASS was able to discriminate between those patients who did and did not require hospitalization, with area under the receiver operating characteristic curve of 0.82. Finally, the PASS was shown to be responsive, with a 48% relative increase in score from start to end of treatment and an overall effect size of 0.62, indicating a moderate to large effect.

CONCLUSIONS

This clinical score, the PASS, based on three clinical findings, is a reliable and valid measure of asthma severity in children and shows both discriminative and responsive properties. The PASS may be a useful tool to assess acute asthma severity for clinical and research purposes.

Near-fatal asthma: a population-based study of risk factors

BACKGROUND

The study of near-fatal asthma (NFA) may provide a means to further our understanding of fatal asthma. Studies of NFA often are derived from a single ICU rather than from a defined population. We therefore aimed to identify factors distinguishing NFA patients (cases) from those persons treated in an emergency department (ED) [ED control subjects] and in the community (community control subjects [CCs]).

METHODS

This was a population-based case-control study conducted over 20 months of 45 NFA patients (age range, 5 to 50 years), 197 ED control subjects treated in an ED, and 303 CCs, all of whom were residents of Alberta.

RESULTS

The age distribution was similar between NFA patients and control subjects, with the majority being < 22 years of age (NFA patients, 68.9%; ED control subjects, 71.3%; CCs, 60.7%). Those patients with NFA were significantly more likely to have received a diagnosis before 5 years of age (66.6%), compared to ED control subjects (39.6%) and CCs (28.7%). The NFA group was significantly more likely to report moderate-to-severe disease and more frequent symptoms than the other groups. Therapy with bronchodilators was used most frequently by the NFA group compared to the ED control subjects and CCs (p < 0.001), as was therapy with inhaled steroids (p < 0.001) and oral steroids (p < 0.001). NFA patients had higher scores for vulnerability and were most likely to admit to stress as an asthma trigger. All groups had high exposure to cigarette smoke and pets.

CONCLUSION

NFA patients have many modifiable risk factors and many similarities to ED control subjects and CCs with asthma. General measures to improve asthma control and awareness of risks are required in all groups.

Contemporary approach to the emergency department management of pediatric asthma

Asthma continues to be an enormous health problem and economic burden in US society. EDs probably will continue to provide a substantial amount of care for those affected by the disease. Pediatric asthma patients frequently are encountered in EDs. Emergency physicians must remain current in their approach to providing expert care while the management of acute asthma exacerbations continues to evolve, older therapies are challenged and new therapies are developed, tested, and implemented.

Inter-rater evaluation of a clinical scoring system in children with asthma

BACKGROUND

Many clinical scores that measure the degree of asthma are used without adequate evaluation of inter-rater reliability. When reliability is tested, most often the Cohen K statistic is used, which limits the comparative results of only two raters at a time.

OBJECTIVE

To evaluate inter-rater agreement of a clinical asthma score using a multi-rater K statistic.

METHODS

Four raters administered a clinical asthma score to 17 children with clinical asthma. Five items were evaluated: O2 requirement, inspiratory breath sounds, accessory muscle use, expiratory wheeze, and cerebral function. For each, a score of zero indicated a normal state; one, moderate impairment; two, severe impairment. A multi-rater kappa statistic was used as a measure of agreement among all four raters simultaneously. This was applied using hand calculations then cross-checked by using a standard statistical syntax, a component of the Statistical Package for Social Sciences (SPSS 9.0).

RESULTS

Application of the multi-rater K statistic revealed strong agreement among raters on oxygenation (K = 0.759), moderate agreement for expiratory wheeze and cerebral function (K = 0.698), and poor agreement for accessory muscle use (K = 0.528) and inspiratory breath sounds (K = 0.316).

CONCLUSIONS

The level of agreement varied by item with the least subjective item, O2 requirement, demonstrating the highest inter-rater correlation. A multi-rater kappa statistic can be applied to data obtained from a clinical scoring instrument either manually or by using statistical syntax provided by SPSS.

Provider adherence to a clinical practice guideline for acute asthma in a pediatric emergency department

Critics of the use of clinical practice guidelines (CPGs) in an emergency department (ED) setting believe that they are too cumbersome and time-consuming, but to the best of the authors' knowledge, potential barriers to CPG adherence in the ED have not been prospectively evaluated.

OBJECTIVES

To measure provider adherence to an ED CPG based on National Asthma Education and Prevention Program (NAEPP) recommendations, and to determine factors associated with provider nonadherence.

METHODS

Prospective, cohort study of children aged 1-18 years with the diagnosis of an acute exacerbation of asthma who were seen in a pediatric ED and requiring admission, as well as a random selection of children discharged to home following pediatric ED care. The following adherence parameters were assessed: at least three nebulized albuterol treatments in the first hour; early steroid administration (after the first nebulizer treatment); clinical assessments using pulse oximetry and peak expiratory flow (PEF) (for children >6 years old); and use of a clinical score to assess acute illness severity (Asthma Severity Score). Nonadherence was defined as any deviation of the above parameters.

RESULTS

Between July 1, 1998, and June 30, 1999, 369 patients were studied. Of these, 38% (139) were discharged to home, 38% (140) were admitted to the observation unit, and 24% (90) were admitted to the inpatient unit. Illness severities at initial presentation to the ED were: 24% (86) had mild exacerbations, 59% (212) had moderate exacerbations, and 17% (62) had severe exacerbations. Sixty-eight percent (95% CI = 63% to 73%) of the patients were managed with complete adherence to the CPG. Of the 32% with some form of nonadherence, most (63%) were children older than 6 years; in this group 64% (48/75) were nonadherent due to lack of PEF assessment. When PEF assessment was disregarded, an 83% (95% CI = 79% to 87%) adherence to the CPG was achieved. Other nonadherence factors included: lack of at least three nebulized albuterol treatments provided timely within the first hour (5%); delay in steroid administration (6%); lack of pulse oximeter use (0.5%); and failure to record clinical score to assess severity (1.1%). Patient age, illness severity (acute and chronic), first episode of wheezing, and high ED volume periods (evenings and weekends) did not worsen adherence.

CONCLUSIONS

Clinical practice guidelines can be used successfully in the pediatric ED and provide a more efficient management and treatment approach to acute exacerbations of childhood asthma. With a systematic and concise CPG, barriers to adherence in a pediatric ED appear to be minimal, with the exception of using PEF in the routine ED assessment.

Efficacy of IV theophylline in children with severe status asthmaticus

STUDY OBJECTIVE

To determine whether adding IV theophylline to an aggressive regimen of inhaled and IV beta-agonists, inhaled ipratropium, and IV methylprednisolone would enhance the recovery of children with severe status asthmaticus admitted to the pediatric ICU (PICU).

DESIGN

A prospective, randomized, controlled trial. Asthma scoring was performed by investigators not involved in treatment decisions and blinded to group assignment.

SETTING

The PICU of an urban, university-affiliated, tertiary-care children's hospital.

PATIENTS

Children with a diagnosis of status asthmaticus who were admitted to the PICU for < or = 2 h and who were in severe distress, as indicated by a modified Wood-Downes clinical asthma score (CAS) of > or = 5.

INTERVENTIONS

All subjects initially received continuous albuterol nebulizations; intermittent, inhaled ipratropium; and IV methylprednisolone. The theophylline group was also administered infusions of IV theophylline to achieve serum concentrations of 12 to 17 microg/mL. A CAS was tabulated twice daily.

MEASUREMENTS AND RESULTS

Forty-seven children (median age, 8.3 years; range, 13 months to 17 years) completed the study. Twenty-three children received theophylline. The baseline CASs of both groups were similar and included three subjects receiving mechanical ventilation in each group. All subjects receiving mechanical ventilation and theophylline were intubated before drug infusion. Among the 41 subjects who were not receiving mechanical ventilation, those receiving theophylline achieved a CAS of < or = 3 sooner than control subjects (18.6 +/- 2.7 h vs 31.1 +/- 4.5 h; p < 0.05). Theophylline had no effect on the length of PICU stay or the total incidence of side effects. Subjects receiving theophylline had more emesis (p < 0.05), and control patients had more tremor (p < 0.05).

CONCLUSIONS

Theophylline safely hastened the recovery of children in severe status asthmaticus who were also receiving albuterol, ipratropium, and methylprednisolone. The role of theophylline in the management of asthmatic children in impending respiratory failure should be reexamined.

Hospital admissions and readmissions for asthma in the age group 0-4 years

SUMMARY. Childhood rates for admission and readmission for asthma are highest under the age of 5 years. From a registration study in 0-4-year-olds, 100 patients (68 male) were admitted to hospital for asthma and followed for 1 year, yielding a total of 136 admissions. To examine factors that may play a role in admissions and readmissions, histories and laboratory tests for atopic status at initial presentation, and clinical data on admission were evaluated. Age groups 0-1 year (n = 54) and 2-4 years (n = 46) were analyzed separately, of whom 20 (37%) and 9 (20%) patients, respectively, had at least one readmission. In the age group 2-4 years, patients with antibodies against inhalant allergens, determined by radioallergosorbent test (RAST), had a significantly higher risk of readmission (RR = 1.54; 95% CI, 1.22-1.95). In the age group 0-1, year prevalence of sensitization to inhalant allergens was low (20% vs. 72% in age group 2-4 years) and constituted only a slight risk (P = 0.097) for readmission. A history of eczema showed a negative association in the age group 0-1 year. Treatment of the first admission did not differ between children only admitted once and those requiring readmission. In both age groups, clinical features at admission did not differ significantly between first and subsequent admissions, and neither did length of stay. Number of readmissions were higher in the age group 0-1 year than in the age group 2-4 years (27/81 (33%) vs. 9/55 (16%), P = 0.028), with no indication of a lower threshold for admission. In the age group 0-1 year, 60% of the readmissions occurred within 2 months of first hospitalization. Moreover, in the age group 0-1 year a trend was observed that inhaled steroids were prescribed less frequently on discharge following first admission in those children who were readmitted than in the children who had a first admission only (4/20 (20%) vs. 15/34 (44%), P = 0.073). More "aggressive" therapy with anti-inflammatory drugs and close medical follow-up after discharge seem to be indicated.

The Preschool Respiratory Assessment Measure (PRAM): a responsive index of acute asthma severity

OBJECTIVE

To elaborate and validate a Preschool Respiratory Assessment Measure (PRAM) that would accurately reflect the severity of airway obstruction and the response to treatment in young patients with asthma.

STUDY DESIGN

A prospective cohort study was performed in 217 children aged 3 to 6 years who presented to a pediatric emergency department with acute asthma. Respiratory resistance measured by forced oscillation served as a gold standard. Children were randomized to either the test group, in which multivariate analyses were performed to elaborate the PRAM, or the validation group, in which the characteristics of the PRAM were tested.

RESULTS

For the test group (N = 145), the best multivariate model contained 5 variables: wheezing, air entry, contraction of scalenes, suprasternal retraction, and oxygen saturation. In the validation group (N = 72), the PRAM correlated substantially with the change in resistance (r = 0.58) but modestly with the % predicted resistance measured before (r = 0.22) and after bronchodilation (r = 0.36). A change of 3 (95% CI: 2.2, 3.0) indicated a clinically important change.

CONCLUSIONS

PRAM appears to be a responsive but moderately discriminative tool for assessing acute asthma severity. This measure, designed for preschool-aged children, has been validated against a concurrent measure of lung function.

Validation of a pediatric asthma caregiver diary

BACKGROUND

Young children are generally not able to consistently and reliably perform tests of airway function, and normative values are not available. Reliable and valid measures of parental reporting of asthma symptoms and functioning are needed to determine the efficacy of asthma interventions.

OBJECTIVE

A pediatric asthma caregiver diary was developed and validated for use in interventional asthma studies.

METHODS

A 3-week prospective study of 125 caregiver parents and their children, aged 2 to 5 years, with persistent asthma was conducted. At baseline, children were classified as either stable (no change to anti-inflammatory therapy) or unstable (anti-inflammatory therapy added or increased).

RESULTS

A symptom scale and day without asthma symptoms (DWAS) were defined from pediatric asthma caregiver diary questions. The scale and DWAS statistically differentiated between the stable and unstable groups at week 1 and detected change between the 2 groups (P <.01). On average, caregivers reported low symptom scores. However, the frequency of DWAS was only 43% of days in the stable group and 22% in the unstable group.

CONCLUSION

The pediatric asthma caregiver diary scale and DWAS have acceptable measurement characteristics for use in clinical trials of children with asthma symptoms. The DWAS indicates an opportunity for improvement in asthma control in this population.

High-dose albuterol by metered-dose inhaler plus a spacer device versus nebulization in preschool children with recurrent wheezing: A double-blind, randomized equivalence trial

Inhaled albuterol is the most frequently used bronchodilator for acute wheezing, and nebulization is the standard mode of delivery in hospital setting. However, recent guidelines consider spacer devices as an easier to use, and cost-saving alternative and recommend the high-dose metered-dose inhaler bronchodilator.

OBJECTIVE

To demonstrate clinical equivalence between a spacer device and a nebulizer for albuterol administration.

DESIGN

Randomized, double-blind, parallel group equivalence trial.

SETTING

Pediatric emergency wards at 2 tertiary teaching hospitals.

PATIENTS

Sixty-four 12- to 60-month-old children with acute recurrent wheezing (32 per group).

INTERVENTIONS

Albuterol was administered through the spacer device (50 microg/kg) or through the nebulizer (150 microg/kg) and repeated 3 times at 20-minute intervals. Parents completed a questionnaire.

OUTCOME MEASURES

Pulmonary index, hospitalization, ease of use, acceptability, and pulse oximetry saturation.

RESULTS

The 90% confidence interval of the difference between treatment groups for the median absolute changes in pulmonary index values between T0 and T60 was [-1; +1] and was included in the equivalence interval [-1.5; +1.5]. Clinical improvement increased with time. Less than 10% of the children (3 in each group) required hospitalization (2 in each group attributable to treatment failure). Parents considered administration of albuterol using the spacer device easier (94%) and better accepted by their children (62%).

CONCLUSIONS

The efficacy of albuterol administered using the spacer device was equivalent to that of the nebulizer. Given its high tolerance, repeated 50-microg/kg doses of albuterol administered through the spacer device should be considered in hospital emergency departments as first-line therapy for wheezing.

Improved outcomes for hospitalized asthmatic children using a clinical pathway

BACKGROUND

Although asthma clinical pathways are used with increasing frequency, few controlled studies have evaluated the clinical and cost effectiveness of these pathways.

OBJECTIVE

To evaluate the effect of an inpatient asthma clinical pathway on cost and quality of care for children with asthma.

METHODS

One hundred forty-nine children were treated for status asthmaticus using an asthma clinical pathway in a children's hospital between September and December 1997. Thirty-four of 149 children treated with the clinical pathway were randomly selected. A retrospective cohort control group of non-pathway patients (N = 34) was matched with each pathway patient by age, race, gender, co-morbidities, asthma severity score, ICU admission, and time of year admitted. Differences between the two groups in length of stay, total costs, readmission rate, inpatient management, and discharge medications were compared.

RESULTS

Length of stay was significantly lower in the clinical pathway group compared with the control group (36 hours versus 71 hours, P < .001) and total costs decreased significantly ($1685 versus $2829, P < .001) as a result of the pathway. Asthmatic children on the clinical pathway were significantly more likely than the control group to complete asthma teaching while hospitalized (65% versus 18%, P < .001), to be discharged with a prescription for a controller medication (88% versus 53%, P < .01), and to have a peak flow meter (57% versus 23%, P < .05) and a spacer device (100% versus 71%, P < .001) for home use.

CONCLUSION

Implementation of this inpatient clinical pathway led to a decrease in length of stay and a reduction in total cost while improving quality of care for hospitalized asthmatic children.

An English and Spanish Pediatric Asthma Symptom Scale

BACKGROUND

Pediatric asthma survey measures have not been adequately tested in non-English-speaking populations.

OBJECTIVES

To test the reliability and validity of an English and Spanish symptom scale to measure asthma control in children.

SUBJECTS

Parents (54% Spanish-speaking; 61% not high school graduates) of 234 children seen in the emergency department for an asthma exacerbation.

MEASURES

Parent report of frequency and perceived severity of child asthma symptoms during the beginning and after resolution of the exacerbation.

RESULTS

An 8-item scale composed of reports of cough, wheezing, shortness of breath, asthma attacks, chest pain, night symptoms, and overall perceived severity had very good psychometric properties in both English and Spanish. The reliability (Cronbach's alpha) of the scale ranged from 0.81 to 0.87 for both languages and time frames. In both languages, the validity of the scale was supported by responsiveness to changes in clinical status (lower symptom score after resolution of the exacerbation, P < 0.001) and by moderate to strong correlations (P < 0.001) with other asthma morbidity measures (parent report of child bother: r = 0.59-0.65; school days lost: r = 0.38-0.67; and activity days lost: r = 0.41-0.59). There were no statistically significant differences in the reliability or construct validity of the summary symptom scale by language, although Spanish speakers reported a lower frequency of some symptoms than did English speakers.

CONCLUSIONS

A reliable and valid 8-item scale can be used to measure control of asthma symptoms in Spanish-speaking populations of low literacy. Additional research to evaluate language equivalency of asthma measures is necessary.

Validation of a predictive model for asthma admission in children: how accurate is it for predicting admissions?

We studied 364 index presentations to the Emergency Department of a children's hospital with a diagnosis of asthma. The admission rate for this group of children was about 31%. We developed a parsimonious multiple logistic regression model to predict asthma hospital admission based on asthma severity indicators. We then evaluated the model's predictive ability using two methods of cross-validation, using the same sample that was used for the predictive model, and using data from a split sample. The logistic regression model had a predictive accuracy of 90% (95% confidence interval 85-95%). The sensitivity and specificity were 86% and 88%, respectively. Cross-validation models confirmed that the predictive ability of the model was stable. In studies with limited sample sizes, it is possible to validate a model without setting aside a split sample for cross-validation.

Features that distinguish those who die from asthma from community controls with asthma

To evaluate risk factors for asthma mortality, an unmatched case-control study was undertaken in the Canadian prairie provinces of Alberta, Saskatchewan, and Manitoba. Those between the ages of 5 and 50 (inclusive) who died from an acute exacerbation of asthma were compared to a control group of people with asthma from the same geographical areas who were contacted using random-digit dialing. Because no deaths occurred among residents less than 15 years old, this analysis was limited to cases and controls between 15 and 50 years old. Of the 38 deaths that occurred between November 1992 and October 1995, data were obtained from next of kin for 35 (92.1%). Of the 210 potential controls that were identified, 142 returned completed questionnaires (67.6%). Cases were more likely than controls to have asthma reported to be severe, to have experienced nocturnal symptoms, to have had cardiopulmonary resuscitation (CPR)/intubation, and to have had more healthcare utilization in the previous year. Medication use was also more common among cases compared to controls. Specific asthma triggers were reported more often for cases than controls; weather changes, excitement, depression, and stress showed the greatest case control differences. Although a number of very strong risk factors for death from asthma were identified, death from asthma is so rare in this age group that it is not possible to label an individual as "likely" to die from asthma. Nonetheless, patients, caregivers, and health professionals should be aware of indicators that would suggest greater risk.

Respiratory resistance in the emergency department: a reproducible and responsive measure of asthma severity

OBJECTIVES

To determine, in preschool children with an acute asthma exacerbation, the responsiveness to change of respiratory resistance measurements obtained by the forced oscillation (Rfo) technique, and to identify the magnitude of change indicative of airway obstruction reversibility.

DESIGN/SETTING

A prospective observational study of 114 children, aged 3 to 17 years, untrained in the Rfo technique and treated for acute asthma in a tertiary-care pediatric emergency department (ED).

MEASUREMENTS

A physical examination followed by three measurements of respiratory resistance by forced oscillation were obtained at 8 Hz (Rfo8) and at 16 Hz (Rfo16). In cooperative children, routine spirometry that included FEV1 was also performed on the Custo Vit R (Custo Med; Munich, Germany). All measurements were obtained twice during the course of the ED treatment, before and after treatment with nebulized bronchodilators.

RESULTS

The Rfo8 and Rfo16 measurements were highly reproducible (reproducibility coefficients >0.85). Both the Rfo8 and Rfo16 were at least as responsive to change (responsiveness coefficients of 2.3 and 1.2, respectively) as was FEV1 (2.0) and the four clinical signs most sensitive to change (0.6 to 1.0). A 19% change in Rfo8 was suggestive of significant reversibility.

CONCLUSIONS

In the assessment of children aged > or =3 years with acute asthma exacerbation, the respiratory resistance measurements are highly reproducible and responsive to change, particularly when obtained at 8 Hz. A 19% change from baseline Rfo8 is suggestive of reversibility. This technique appears to be an attractive alternative in the evaluation of children who are too young or too sick to perform spirometry reproducibly.

Admission rates as an indicator of the prevalence of severe asthma in the community

BACKGROUND

A reliable indicator of the prevalence of severe asthma in the community is needed to monitor population-based asthma control strategies. We examined the potential use of asthma admissions to hospital as such an indicator.

METHODS

We recruited subjects from the Emergency Department (ED) of a children's hospital. The attending doctor completed the 'physician questionnaire' which included questions on the patient's asthma severity and interval severity/chronicity of asthma. The parent/guardian completed the 'parent questionnaire'. It included questions on demography, asthma knowledge and attitudes, asthma history and social support. We performed univariate and multiple logistic regression to determine predictors for hospital admission.

RESULTS

Interval severity of asthma, pre-treatment severity of wheeze and low post-treatment pulse oximetry best predicted whether children presenting with asthma were admitted. Demographic variables, factors associated with access to health services and factors related to the asthma history and management were not significant predictors of admission.

DISCUSSION

At the population level, it may be possible to utilise routine hospital admission rates as an indicator of the prevalence of severe asthma in the community, especially within the context of monitoring trends in asthma prevalence. Our study was conducted in a metropolitan tertiary paediatric hospital. The reliability of hospital admission rates as indicators of the prevalence of severe asthma in other hospital settings, in different population groups and over time remains to be established.