Epidemiology, pathophysiology and clinical aspects of acute severe asthma in children.

Therapy for asthma is being prescribed more frequently. However, asthma mor tality remains high in many countries. Fatal outcome is not always related to inadequate follow-up. In this article we report that children with mild to moderate symptoms may present a fatal attack. Many factors are responsib le for such an outcome: asphyxia +++ due to ventilation/perfusion mismatch and/or bronchospasm, cardiac failure, cardiac arrhythmia, intrinsic positiv e expiratory pressure, or metabolic disturbances (hypokaliemia, for example ). Such problems can occur in predisposed patients: it has been shown that the chemosensitivity to hypoxia and the perception of dyspnoea are altered in certain patients with near-fatal asthma. It is very important to identif y children at risk of severe asthma and to organize care so as to optimize the management of such children. (C) 1999 Elsevier, Paris.