Asthma, Acute

Prevalence in USA: 25 million people; nearly 5% for persons age 5-34 y

Increased prevalence and severity in African Americans, adult females, and atopic individuals

Risk related to degree of preop control of symptoms and optimization of medication regimen

Morbidity due to bronchospasm and laryngospasm

Bronchospasm

Hyperinflation of lungs

Medication side effects (e.g., β-agonists causing tachycardia and hypokalemia)

Adrenal insufficiency (chronic corticosteroid use)

Characterized by chronic bronchial wall inflammation, reversible expiratory airflow obstruction, airway hyperreactivity, wheezing, dyspnea, and cough.

Type I exacerbation: “slow-onset, late arrival,” slow and progressive obstruction.

• Inadequate asthma control, treatment, and/or compliance; preventable with better preoperative control (e.g., adding an inhaled corticosteroid).

• Often overusing bronchodilators, maximally relaxed smooth muscle, inflammation undertreated, and airway edema present.

• Additional beta-2 agonists not helpful, present with secretions and mucous plugging and eosinophilic infiltration; slower response to treatment.

• Majority of asthma fatalities.

Type II exacerbation: “Sudden-onset, fatal asthma,” rapid and in response to an allergen.

• Little airway inflammation, predominantly neutrophilic infiltration.

• Reaction is typically in response to a specific allergen.

• Rapidly respond to bronchodilators.

• Respiratory arrest, acidemia, and altered mental status more likely than with type I.

• More likely to improve with appropriate treatment