Inhalational anesthetics in acute severe asthma

Acute severe asthma is characterized by a state of airway inflammation and increased bronchiolar smooth-muscle tone that leads to increased resistance to expiration and lung hyperinflation. Despite the better knowledge of its pathophysiology, the incidence and severity of asthma in the last twenty years is increased worldwide, although with significant age and geographic variation. As a result, the number of patients requiring more intensive medical therapy has also increased. In the most severe cases, often referred to as near-fatal asthma, the institution of mechanical ventilation may be required. Volatile anesthetics have bronchodilator effects on the bronchial smooth muscle. The use of inhalational anesthetic agents for treatment of severe status asthmaticus has been documented in case reports, case series and small uncontrolled studies. Their use may be considered in any mechanically ventilated patients whose severe bronchospasm failed to respond to maximal medical treatment. In the present review article, we aim to provide a brief description of the physio-pathological and clinical features of acute severe asthma, and of the principles of treatment, focusing our attention on the use of the inhalational anesthetics in severe patients requiring mechanical ventilation and not responding to conventional therapy.