Asthma is a very common pulmonary problem affecting between three and five percent of the population. Fortunately, fatal asthma is a rare complication, though it often involves young people in the prime of their lives. The definition of asthma is reversible airway obstruction and involves inflammation and narrowing of the airways. Patients experience shortness of breath and feel as if they are breathing through a straw. Allergies, exercise, infections, and stress may cause an acute worsening of their condition.
Fortunately, the overwhelming majority of asthmatics experience mild symptoms that are easily treated with medications which open up the airway and reduce inflammation in those structures. A certain subset however, have more severe narrowing of the airways and must be treated more aggressively and monitored more carefully with serial pulmonary function testing.
Patients with severe asthma require more medication, have more frequent visits to the emergency room, and may actually require mechanical ventilation for acute respiratory failure. These patients constitute a high-risk group for a fatal outcome and generally have certain risk factors, such as steroid dependence, prior need for mechanical ventilation, a high number of medications, and frequent episodes of acute respiratory failure. Aggressive treatment in this group prevents accumulation of dried secretions in the airways as well as severe life threatening airway obstruction. Once this process occurs, these patients are faced with a significant increase “work of breathing” which eventually leads to respiratory muscle fatigue.
Asthmatics who eventually go on to develop acute respiratory failure experience a gradual drop in blood oxygen and eventually, an elevated arterial carbon dioxide level during the time when most of their strength is devoted to breathing. As oxygen continues to drop and pressure inside the chest rises due to an increased respiratory effort, the heartbeat may become irregular which can result in a fatal cardiac arrhythmia if the problem is not solved immediately.
Early treatment of asthma actually prevents the accumulation of dried secretions in the airways, as well as the narrowing of those structures. As that process progresses however, treatment becomes increasingly difficult, which may eventually place these patients at high risk for a fatal outcome. Appropriate management therefore, involves aggressive treatment at an early stage in order to prevent these patients from progressing to a stage where they eventually become at high risk for a fatal outcome.
© June 2006. James F. Lineback, MD, FCCP. All Rights Reserved. Excerpt from monthly Newsletter.