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Sunday, September 15, 2013

Asthma

Asthma is a common chronic disease worldwide and affects approximately 24 million persons in the United States. It is the most common chronic disease in childhood, affecting an estimated 7 million children. The pathophysiology of asthma is complex and involves airway inflammation, intermittent airflow obstruction, and bronchial hyperresponsiveness.

Essential update: Bronchial thermoplasty provides relief for asthmatics

According to a recent study of 136 asthma patients in the UK, 46 (34%) of whom were eligible for the treatment, bronchial thermoplasty may be an effective treatment option for difficult-to-treat asthma and may help reduce maintenance treatment and healthcare utilization. Bronchial thermoplasty uses a catheter tipped with a wire probe to deliver thermal energy to the airway wall to reduce the mass of airway smooth muscle.
Results of the study showed that the treatment lowered the need for reliever medication and improved overall symptoms. Mean dose of inhaled corticosteroids was equivalent to 2300 μg beclomethasone dipropionate and 41% of the patients received maintenance oral corticosteroids. Five patients had ≥1 admission to the high dependency or intensive therapy unit of the hospital, and nearly half had ≥1 admission to the hospital. Ten patients initiated treatment with omalizumab.

Signs and symptoms

Signs and symptoms of asthma include the following:
  • Wheezing
  • Coughing
  • Shortness of breath
  • Chest tightness/pain
Other nonspecific symptoms in infants or young children may be a history of recurrent bronchitis, bronchiolitis, or pneumonia; a persistent cough with colds; and/or recurrent croup or chest rattling.
See for more detail.

Diagnosis

Updated guidelines from the National Asthma Education and Prevention Program highlight the importance of correctly diagnosing asthma, by establishing the followin:
  • Episodic symptoms of airflow obstruction are present
  • Airflow obstruction or symptoms are at least partially reversible
  • Exclusion of alternative diagnoses
Spirometry with postbronchodilator response should be obtained as the primary test to establish the asthma diagnosis. Pulse oximetry measurement is desirable in all patients with acute asthma to exclude hypoxemia. The chest radiograph remains the initial imaging evaluation in most individuals with symptoms of asthma, but in most patients with asthma, chest radiography findings are normal or may indicate hyperinflation. Exercise spirometry is the standard method for assessing patients with exercise-induced bronchospasm.
See for more detail.

Management

For all but the most severely affected patients, the ultimate goal is to prevent symptoms, minimize morbidity from acute episodes, and prevent functional and psychological morbidity to provide a healthy (or near healthy) lifestyle appropriate to the age of child.
Pharmacologic treatment
Pharmacologic management includes the use of relief and control agents. Control agents include inhaled corticosteroids, inhaled cromolyn (Intal) or nedocromil (Tilade), long-acting bronchodilators, theophylline (Theo-24, Theochron, Uniphyl), leukotriene modifiers, and anti-IgE antibodies. Relief medications include short-acting bronchodilators, systemic corticosteroids, and ipratropium (Atrovent).
The pharmacologic treatment of asthma is based on stepwise therapy. Asthma medications should be added or deleted as the frequency and severity of the patient's symptoms change.
Allergen avoidance
Environmental exposures and irritants can play a strong role in symptom exacerbations. The use of skin testing or in vitro testing to assess sensitivity to perennial indoor allergens is important. Once the offending allergens are identified, counsel patients on how to avoid them. Efforts should focus on the home, where specific triggers include dust mites, animals, cockroaches, mold, and pollen.