Rescue! Therapy and the paradox of the Barcalounger.

12 A ship sinks at sea. The occupants are left floating in the ocean aided only by their life preservers and buoyant pieces of debris. Fortunately, a CoastGuard cutter, attracted by an SOS sent from the sinking ship, arrives and saves the day. This is a rescue. Asthma is characterised by episodes of acutely worsening airflow, secondary to bronchospasm. An asthmatic, when exposed to a trigger, may develop acute bronchospasm, together with frightening and sometimes life-threatening symptoms. Rapid-acting bronchodilators, administered in a timely way, can reverse the bronchospasm, thus saving the day. This is termed "rescue" in asthma therapy. Acute episodes of asthma can be initiated by a variety of triggers ranging from cold air, cigarette smoke, dust, perfume and viral infections, to a variety of allergens including animal dander, insect and mite proteins, plant pollens and mould spores. An asthma attack can vary in severity, rate of onset and rate of resolution. Unexpected symptoms may be less dramatic and relatively mild and may commonly occur in some asthmatics. Unscheduled use of rapid-acting broncho-dilators taken for acute symptom relief for all these various episodes is termed "rescue". This use of rescue treatment has several utilities. Reserving the term rescue for severe "attacks" would require a definition of attacks, a daunting prospect. The concept also has mechanistic validity. The airway in the asthmatic with baseline conditions has its "normal" luminal diameter and airway tone. In response to a stimulus, airway tone acutely increases while airflow acutely decreases. Therefore, when the asthmatic experiences acute symptoms, an acute alteration in the airway diameter is present that can be acutely remedied. Moreover, the use of rescue medication has proved an important and robust parameter, both for assessing the efficacy of therapeutic agents designed to prevent worsening symptoms and in assessing overall asthma control. As a result, the availability and use of rescue medicines constitutes an important goal in current asthma treatment and patient education. Consistent with this, the proper use of rescue medicines is highlighted in current asthma guidelines [1]. Rescue medication use, therefore, is a routine parameter assessed in clinical trials. Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death in the USA, and will be the third leading cause of death worldwide by the year 2020 [2]. The most common cause of COPD is cigarette smoking, but as many as 20% of patients are lifelong nonsmokers [3]. COPD …