Chest
ReviewsStatus Asthmaticus in Children: A Review
Section snippets
Definition
Status asthmaticus is the condition of a patient in progressive respiratory failure due to asthma, in whom conventional forms of therapy have failed.1 The exact definition differs between authors. For practical clinical purposes, any patient not responding to initial doses of nebulized bronchodilating agents should be considered to have status asthmaticus.2
Epidemiology
About 10% of children in the United States have asthma.3 Asthma has become the most common chronic illness of childhood in the United States.4 Dramatic worldwide variations in asthma prevalence have been found, with the highest rates in the United Kingdom, Australia, and New Zealand, and the lowest prevalence in Eastern Europe, China, and India.5,6 Its prevalence is increasing, especially in children < 12 years of age.4,7 Diagnostic shift, ie, the use of “ asthma” for conditions previously
Risk Factors
The definition of criteria to identify children with potentially fatal asthma has proven to be difficult. Although several contributors to the mortality risk have been described, as many as one third of children who die from asthma may have only had mild asthma before, and were not previously classified as “high risk” by any available criteria. In their review of 51 pediatric deaths from asthma in Australia, Robertson et al10 found that only 39% had potentially preventable elements. Known
Pathophysiology
Asthma is characterized by reversible, diffuse lower-airway obstruction, caused by airway inflammation and edema, bronchial smooth-muscle spasm, and mucous plugging. During the last 2 decades, chronic airway inflammation, rather than smooth-muscle contraction alone, has been recognized as playing the key role in the pathogenesis of asthma.29,30 Lymphocytic and eosinophilic submucosal infiltrates, seen on tracheal and bronchial biopsy specimens from adult asthmatic patients, appear to correlate
General
The child with status asthmaticus usually presents with cough and wheezing, and exhibits signs of dyspnea, increased work of breathing, and anxiety. However, the sick asthmatic child may also present in respiratory failure or even frank cardiopulmonary arrest. The degree of wheezing does not correlate well with severity of disease.80 The clinician should be reassured by the noisy chest in a child with severe asthma, as sufficient airflow is present to cause turbulence and vibration, and thus
General
Any child in status asthmaticus requires cardiorespiratory monitoring. A comfortable and supportive environment should be provided, ideally with a parent or family member present. While hypoxemia and anxiety will lead to agitation and restlessness, sedatives are contraindicated in the nonintubated asthmatic patient.
Oxygen
All patients with asthma have ventilation/perfusion mismatch and thus require humidified oxygen. High-flow supplemental oxygen is best delivered via a partial or nonrebreather mask.
Summary
Severe asthma in children is increasing in prevalence and mortality. Even in the very-sick-appearing asthmatic child, an aggressive treatment trial of β-agonists, anticholinergics, and corticosteroids is warranted. Intubation and mechanical ventilation carry a significant risk of worsening bronchospasm and hyperinflation, barotrauma, and cardiovascular depression. It should be delayed as long as possible, but mechanical ventilation is indicated for respiratory failure or a rapid decrease in
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