Chapter 13: Potentially (near) fatal asthma.

Potentially (near) fatal asthma (PFA) defines a subset of patients with asthma who are at increased risk for death from their disease. The diagnosis of PFA should motivate treating physicians, health professionals, and patients to be more aggressive in the monitoring, treatment, and control of this high-risk type of asthma. A diagnosis of PFA is made when any one of the following are present: (1) history of endotracheal intubation from asthma, (2) acute respiratory acidosis (pH < 7.35) or respiratory failure from acute severe asthma, (3) two or more episodes of acute pneumothorax or pneumomediastinum from asthma, (4) two or more episodes of acute severe asthma despite the use of long-term oral corticosteroids and other antiasthma medications. There are two predominant phenotypes of near fatal exacerbations, the "subacute" exacerbation and the "hyperacute" exacerbation. The best way to "treat" acute severe asthma is 3-7 days before it occurs (i.e., at the onset of symptoms or change in respiratory function) and to optimize control of asthma by decreasing the number of symptomatic days and days/nights requiring rescue therapy and increasing baseline respiratory status in "poor perceivers." PFA is treated with a multifaceted approach; physicians should appreciate limitations of pharmacotherapy including combination inhaled corticosteroid/long-acting beta-agonist products as well as addressing nonadherence, psychiatric, and socioeconomic issues that complicate care.