Asthma
Asthma is typically reversible, triggered by allergens, exercise, or infection, and common in younger patients. Wheezing, cough, and chest tightness are classic. Bronchodilators and sometimes epinephrine or magnesium sulfate help.
COPD
COPD includes emphysema and chronic bronchitis and is usually seen in older smokers. Patients often have a barrel chest, pursed-lip breathing, and chronic cough. Their airway damage is largely irreversible, but exacerbations respond to bronchodilators and steroids.
Oxygen and Ventilation
Give enough oxygen to correct hypoxia, typically targeting 88 to 92 percent in COPD patients. Do not withhold oxygen from a hypoxic patient out of fear of suppressing respiratory drive. CPAP can prevent intubation in many exacerbations.