Susan frequently suffered from cough, wheezing and chest tightness. These symptoms were usually exacerbated by various environmental allergens, cold air, exercise or respiratory infections. She awakened with nighttime symptoms two to three times per week and had taken oral steroids several times over the last year for worsening symptoms. She was using high dose inhaled steroids daily to decrease airway inflammation and also using inhaled albuterol, a beta adrenergic medication, which relaxes the airway smooth muscle (muscle that controls airway diameter). She had a history of multiple hospitalizations for asthma, including one admission to the intensive care unit two years earlier. At that time, she had required mechanical ventilation (machine-assisted breathing) for several days.
Susan was markedly short of breath and could only speak in short sentences. She had a fever of 101 degrees, was breathing rapidly, and her heart rate was 150/minute. Her air passages were so constricted that she was no longer wheezing and I could barely hear any breath sounds at all. Her lips were a little blue and I measured her oxygen saturation to be only 84% (normally this value is greater than 90%). She was too short of breath for me to measure her peak flows (maximum force of air at outset of exhalation).
Over the next two hours she required multiple nebulized albuterol treatments (aerosolized asthma medications administered by face mask), oxygen by nasal cannula and high doses of intravenous steroids. To my dismay, she did not improve. She was becoming visibly tired, laboring with each breath. Blood was drawn from the radial artery in her wrist in order to measure its carbon dioxide and oxygen levels. I became concerned because her carbon dioxide level was elevated. This is an ominous sign in asthmatic patients, and often indicates the need for mechanical ventilation.
