0071643192.pdf

■ Systemic corticosteroids

■ Oral and intravenous delivery equally effective

■ Decreases the need for hospitalization and subsequent relapse rate

■ Requires about 4 hours to take effect; so, administer early!

■ Discharged patients should continue oral therapy for 3–10 days.

■ Inhaled steroid therapy

■ Mainstay of outpatient treatmentfor controlling exacerbations

■ Beware the expense of treatment.

■ Antibioticsare generally unnecessary. Reserve for patients if an under-

lying bacterial pneumonia is suspected.

■ Magnesium sulfate is somewhat controversial but has been shown to

improve airflow obstruction in patients with severe exacerbations.

■ Helioxmay be helpful. Usually delivered in an 80% (helium)/20% (O 2 )

mixture. As the proportion of O 2 rises, this modality becomes less effective.

■ Assisted ventilation in severe cases of ventilatory failure

■ Noninvasive mechanical ventilation (BiPAP)may be helpful but not

as well established as in CHF and COPD.

■ Mechanical ventilation: Use low tidal volumes (<6 mL/kg) and low

RRs (6–8 bpm) that allow maximum time for expiration.

■ Beware of auto-PEEP and breath stacking leading to barotrauma as

asthma is primarily a disease of prolonged expiratory phase!

CHRONIC OBSTRUCTIVE PULMONARY DISEASE

This disease state is characterized by chronic airflow limitation that is no longer

fully reversible. COPD is usually progressive and results from chronic bron-

chitis and emphysema.

■ Chronic bronchitis is defined clinically as chronic productive cough for

3 consecutive months in 2 consecutive years.

■ Emphysemais defined pathologically as abnormal enlargement of the air-

spaces distal to the terminal bronchioles, with wall destruction.

■ The most important risk factor for developing COPD is cigarette smoking.

α 1 -Antitrypsin (AAT) deficiency is also a well-characterized genetic abnor-

mality that predisposes individuals to the development of early onset

COPD.

SYMPTOMS/EXAM

■ Symptoms are usually not present until the individual has smoked >1 pack

of cigarettes per day for 20 years.

■ The patient typically presents with chronic cough in the fourth or fifth

decade of life. Dyspnea usually occurs only with moderate exercise and

not until the sixth or seventh decade of life.

THORACIC AND RESPIRATORY

DISORDERS

TABLE 10.7. Treatment of Acute Asthma Exacerbations

ALLPATIENTS SELECTEDPATIENTS NOTUSEFUL/HARMFUL

Inhaled bronchodilators Antibiotics Theophylline

Corticosteroids O 2 -assisted ventilation Injected bronchodilators

Magnesium sulfate Mucolytic agents