Nowadays more usually termed acute severe ASTHMA, this is a prolonged period of wheezing and shortness of breath with little or no respite between the spasms, usually lasting for more than 24 hours. The patient is seriously distressed and, untreated, the condition may lead to HYPOXIA and exhaustion. Continuous or very frequent use of nebulised BRONCHODILATORS, intravenous corticosteroid treatment, and other skilled medical care are urgently required, including availability of assisted or ARTIFICIAL VENTILATION OF THE LUNGS.