A new index for early prediction of hospitalization in patients with acute asthma

doi:10.1016/S0735-6757(97)90039-5

The American Journal of Emergency Medicine

Volume 15, Issue 1, January 1997, Pages 8-13

https://doi.org/10.1016/S0735-6757(97)90039-5 Get rights and content

Abstract

Data from studies using the factor analysis technique have shown that asthma appears to be multidimensional and that most of the subjective and objective measures utilized in the assessment of asthma patients represent a much smaller number of underlying dimensions. Additionally, several investigators have emphasized that evaluation of acute asthma is an ongoing process, as the degree and time course of the response to therapy vary considerably between patients. The aim of this study was to examine the usefulness of the most common clinical and objective measures in the evaluation of acute asthma in the emergency department (ED) for predicting the outcome of acute episodes in adults. In an effort to identify variables that can predict the outcome of patients with acute asthma, 184 adults (age 32.4 ± 11.6 [mean ± SD]) (analysis sample) who presented to an ED were studied. The inclusion criteria were: (1) age between 18 and 50 years; (2) a peak expiratory flow rate (PEFR) or forced expiratory volume in the first second (FEV₁) below 50% of predicted; and (3) no history of chronic cough or cardiac, hepatic, renal, or other medical disease. All patients were treated with salbutamol delivered with metered-dose inhaler (MDI) into a spacer device in 4 puffs actuated at 10-minute intervals and 500 mg of intravenous hydrocortisone. The multivariate statistical technique of discriminant analysis was utilized to develop the index, and after this, a new sample (n = 91), the validation sample, was studied to validate the index. In the analysis sample 163 patients (89%) were discharged (relapse rate within 7 days = 10%) and 21 (11%) were hospitalized (mean duration of hospital stay = 5.75 ± 2.81 days). The discriminant analysis identified three independent variables that make the greatest contribution in discriminating between the two groups studied: PEFR variation over baseline, PEFR as percent of predicted, and accessory muscle use, all measured at 30 minutes after the beginning of treatment. A multifactorial index using these three variables presented a sensitivity of 0.86, a specificity of 0.96, a positive predictive value of 0.75, and a negative predictive value of 0.98. The validation sample index sensitivity, specificity, and positive and negative predictive values were 0.83, 0.97, 0.83, and 0.97, respectively. In conclusion, a predictive index has been developed for evaluating patients with asthma who present to an ED. This simple and brief three-item index can facilitate an early decision (30 minutes of treatment) to hospitalize patients with severe asthma.

References (34)

WA Whitelaw
Asthma deaths
Chest
(1991)
E Kerem et al.
Predicting the need for hospitalization in children with acute asthma
Chest
(1990)
WC Bailey et al.
Asthma severity: A factor analytic investigation
Am J Med
(1992)
G Rodrigo et al.
Assessment of the patient with acute asthma in the emergency room: A factor analytic study
Chest
(1993)
AS Rebuck et al.
Assessment and management of severe asthma
Am J Med
(1971)
ER McFadden
Clinical physiologic correlates in asthma
J Allergy Clin Immunol
(1986)
G Rodrigo et al.
Comparison of salbutamol delivered by nebulizer or metered-dose inhaler with a pear-shaped spacer in acute asthma
Curr Ther Res
(1993)
C Rodrigo et al.
Treatment of acute asthma: Lack of therapeutic benefit and increase of the toxicity from aminophylline given in addition to high doses of salbutamol delivered by metered dose inhaler with a spacer
Chest
(1994)
CE Metz
Basic principles of ROC analysis
Semin Nucl Med
(1978)
SB Fiel et al.
Efficacy of short-term corticosteroid therapy in outpatient treatment of acute bronchial asthma
Am J Med
(1983)

R Jackson et al.

International trends in asthma mortality: 1970–1985

Chest

(1988)

Centers for Disease Control

Asthma—United States, 1980–1987

MMWR Mortal Morbid Wkly Rep

(1990)

R Beasley et al.

Asthma mortality and inhaled beta agonist therapy

Aust N Z J Med

(1991)

W Spitzer et al.

The use of β-agonists and the risk of death and near death from asthma

N Engl J Med

(1992)

AS Rebuck et al.

Evaluation of the severity of the acute asthmatic attack

Chest

(1982)

JI Peters et al.

Current concepts in managing status asthmaticus

J Respir Dis

(1992)

MA Fischl et al.

An index predicting relapse and need for hospitalization in patients with acute bronchial asthma

N Engl J Med

(1981)

Cited by (50)

Early Prediction of Intensive Care Admission in Emergency Department Patients With Asthma
2022, Journal of Emergency Medicine
Emergency physicians must choose whether patients with asthma are admitted to a hospital ward or a higher level of care, such as an intermediate care unit (IMC) or intensive care unit (ICU).
This study aimed to determine which variables, available early during emergency department (ED) visits, are associated with IMC/ICU admission.
In this retrospective chart review (records from 2015-2018), two trained abstractors, blinded to study hypothesis, abstracted data on predictor variables and disposition (ward vs. IMC/ICU). Predictor variables were defined explicitly and abstracted from the periods of ED arrival and after treatment with 7.5 mg nebulized albuterol. Distress was defined as tripod positioning or speaking in broken sentences. “Arrival” and “after treatment” scoring systems were derived based on adjusted odds ratios (aOR) for predictor variables. We performed analyses using SAS^Ⓡ, version 9.4 (SAS Institute).
Among 273 patients, 105 required admission to an IMC/ICU. At presentation, distress (aOR 2.1, 95% confidence interval [CI] 1.1–3.9), room air SpO₂ ≥95% (aOR 0.29, 95% CI 0.14–0.62), respiratory rate > 20 breaths/min (aOR 1.9, 95% CI 1.0–3.3), and retractions (aOR 1.9, 95% CI 1.1–3.3) were associated with IMC/ICU admission. After initial bronchodilator therapy, heart rate > 120 beats/min (aOR 7.1, 95% CI 2.0–25), room air SpO₂ ≥ 95% (aOR 0.15, 95% CI 0.07–0.34), and noninvasive ventilation (aOR 6.5, 95% CI 2.5–17) were associated with IMC/ICU admission. Both scoring systems stratified risk of IMC/ICU admission into low-risk (9–10%) and high-risk (70–100%) groups.
Combinations of predictor variables, available early in a patient's stay, stratify risk of admission to an IMC/ICU bed.
Assessment of acute asthma severity in the ED: Are heart and respiratory rates relevant?
2015, American Journal of Emergency Medicine
Assessment of acute asthma severity in the emergency department (ED) determines the appropriate initial therapy. The aim of this study was to evaluate the usefulness of heart and respiratory rates as determinants of severity of asthma exacerbations.
It was a pooled analysis of individual patient data from different controlled clinical trials performed over a 9-year period. The sample was characterized by patients with a diagnosis of asthma, age 18 to 50 years, and a forced expiratory volume in the first second (FEV₁) or a peak expiratory flow less than or equal to 50% of predicted at ED presentation.
One thousand one hundred ninety-two severe acute asthmatics (age 33.9 ± 10.3 years and FEV₁ = 27.4% ± 9.7%) were enrolled. Two-thirds of patients were categorized as having severe acute asthma (FEV₁, 31%-50% of predicted) and the remaining third as life-threatening asthma (FEV₁, ≤ 30% of predicted). There were no relationships between the intensity of airway obstruction as measured by the FEV₁ and the degree of tachycardia (r = 0.05, P > .1) or tachypnea (r = 0.06, P > .1). Only 22% and 19% of the patients, respectively, met the heart rate and respiratory rate requirements for acute severe asthma (≥ 120/min and ≥ 25/min, respectively). In contrast to FEV₁ and arterial oxygen saturation, baseline heart and respiratory rates did not predict admissions of patients at the end of treatment.
This pooled analysis suggests a poor performance of heart and respiratory rates as determinants of acute asthma severity in the ED.
Predicting hospitalization in children with acute asthma
2013, Journal of Emergency Medicine
Citation Excerpt :
In our study, we found that an MPIS ≥ 5 at the 1st hour had a sensitivity and PPV of 42.4% and 41%, respectively, whereas the sensitivity and PPV of moderate/severe attack severity according to the GINA guideline were found to be 44.2% and 38.2%, respectively. Predictive values in our study were not as high as in recent studies (23,29,30,34). Approximately 60% of the patients determined as moderate/severe at the 1st hour were discharged, whereas 14% of the mild attack patients were hospitalized.
Acute asthma is one of the most common medical emergencies in children. Appropriate assessment/treatment and early identification of factors that predict hospitalization are critical for the effective utilization of emergency services.
To identify risk factors that predict hospitalization and to compare the concordance of the Modified Pulmonary Index Score (MPIS) with the Global Initiative for Asthma (GINA) guideline criteria in terms of attack severity.
The study population was composed of children aged 5–18 years who presented to the Emergency Departments (ED) of the tertiary reference centers of the country within a period of 3 months. Patients were evaluated at the initial presentation and the 1^st and 4^th hours.
Of the 304 patients (median age: 8.0 years [interquartile range: 6.5–9.7]), 51.3% and 19.4% required oral corticosteroids (OCS) and hospitalization, respectively. Attack severity and MPIS were found as predicting factors for hospitalization, but none of the demographic characteristics collected predicted OCS use or hospitalization. Hospitalization status at the 1^st hour with moderate/severe attack severity showed a sensitivity of 44.1%, specificity of 82.9%, positive predictive value of 38.2%, and negative predictive value of 86.0%; for MPIS ≥ 5, these values were 42.4%, 85.3%, 41.0%, and 86.0%, respectively. Concordance in prediction of hospitalization between the MPIS and the GINA guideline was found to be moderate at the 1^st hour (κ = 0.577).
Attack severity is a predictive factor for hospitalization in children with acute asthma. Determining attack severity with MPIS and a cut-off value ≥ 5 at the 1^st hour may help physicians in EDs. Having fewer variables and the ability to calculate a numeric value with MPIS makes it an easy and useful tool in clinical practice.
Risk stratification for hospitalization in acute asthma: The CHOP classification tree
2010, American Journal of Emergency Medicine
Simple risk stratification rules are limited in acute asthma. We developed and externally validated a classification tree for asthma hospitalization.
Data were obtained from 2 large, multicenter studies on acute asthma, the National Emergency Department Safety Study and the Multicenter Airway Research Collaboration cohorts. Both studies involved emergency department (ED) patients aged 18 to 54 years presenting to the ED with acute asthma. Clinical information was obtained from medical record review. The Classification and Regression Tree method was used to generate a simple decision tree. The tree was derived in the National Emergency Department Safety Study cohort and then was validated in the Multicenter Airway Research Collaboration cohort.
There were 1825 patients in the derivation cohort and 1335 in the validation cohort. Admission rates were 18% and 21% in the derivation and validation cohorts, respectively.
The Classification and Regression Tree method identified 4 important variables (CHOP): change [C] in peak expiratory flow severity category, ever hospitalization [H] for asthma, oxygen [O] saturation on room air, and initial peak expiratory flow [P]. In a simple 3-step process, the decision rule risk-stratified patients into 7 groups, with a risk of admission ranging from 9% to 48%. The classification tree performed satisfactorily on discrimination in both the derivation and validation cohorts, with an area under the receiver operating characteristic curve of 0.72 and 0.65, respectively.
We developed and externally validated a novel classification tree for hospitalization among ED patients with acute asthma. Use of this explicit risk stratification rule may aid decision making in the emergency care of acute asthma.
The ALERTA-2 Guideline. Latin America and Spain: Recommendations for the prevention and treatment of asthma exacerbations
2010, Archivos de Bronconeumologia
Severe acute asthma: Its management in emergency visits and intensive care
2006, Medicina Intensiva
Todos los pacientes asmáticos tienen riesgo de sufrir una crisis de asma aguda en el curso de su vida, que puede eventualmente llegar a ser fatal. Las hospitalizaciones y su atención a nivel de los servicios de emergencia/cuidado crítico constituyen un aspecto fundamental en la asistencia del asmático, donde se invierte un porcentaje muy importante de los aportes económicos que la sociedad hace en su conjunto, siendo por lo tanto de particular importancia establecer planes de prevención, educación y racionalización terapéutica a nivel de la asistencia primaria que estabilicen la enfermedad y disminuyan las agudizaciones. La severidad de las exacerbaciones puede variar entre una crisis leve hasta un asma potencialmente-fatal o fatal, estando la mortalidad fundamentalmente vinculada a una inadecuada valoración de la severidad del paciente, lo que trae como consecuencia un tratamiento inadecuado en la emergencia y un retraso en su ingreso hospitalario. En esta revisión exploraremos aspectos como la epidemiología, costes, fisiopatología, mortalidad y el manejo del paciente asmático adulto en la emergencia y en el cuidado intensivo, en particular lo relativo a la ventilación mecánica no invasiva y a las formas convencionales de la asistencia respiratoria mecánica, con las actuales modificaciones en su estrategia operativa.
All patients with asthma are at risk of suffering an acute asthma attack over their lifetime, and these may finally be fatal. Hospitalizations and emergency department visits and intensive care account for a large proportion of the health-care cost burden of asthma. Thus, it is especially important to establish plans for prevention, education and therapeutic rationalization of primary care that establishes the disease and decreases its worsening. The severity of the exacerbations may vary from a mild to life threatening. The mortality is basically linked to inadequate assessment of the patient's severity. This leads to inadequate treatment in the emergency and delay in the patient's hospitalization. This review describes the epidemiology, costs, pathophysiology, mortality and management of adult acute asthma patients in the emergency department and intensive care, especially that related to non-invasive mechanical ventilation and conventional forms of mechanical respiratory care, with the current changes in its operational strategy.

View all citing articles on Scopus

View full text

Original contributionA new index for early prediction of hospitalization in patients with acute asthma

Abstract

Chest

Chest

Am J Med

Chest

Am J Med

J Allergy Clin Immunol

Curr Ther Res

Chest

Semin Nucl Med

Am J Med

International trends in asthma mortality: 1970–1985

Chest

Asthma—United States, 1980–1987

MMWR Mortal Morbid Wkly Rep

Asthma mortality and inhaled beta agonist therapy

Aust N Z J Med

The use of β-agonists and the risk of death and near death from asthma

N Engl J Med

Evaluation of the severity of the acute asthmatic attack

Chest

Current concepts in managing status asthmaticus

J Respir Dis

An index predicting relapse and need for hospitalization in patients with acute bronchial asthma

N Engl J Med

Original contribution
A new index for early prediction of hospitalization in patients with acute asthma