 This is a randomized clinical trial studying the effect of nebulized budesonide Pulmicort in acutely ill adults presenting to the Emergency Department with severe asthma. Budesonide is an inhaled steroid FDA approved for the treatment of pediatric chronic asthma. ED entry criteria include hyporesponsiveness to nebulized beta-agonists and an FEV150 predicted. The trial will evaluate the efficacy of multiple doses of nebulized budesonide as an adjunct to a highly regimented standardized treatment protocol; standard care consists of bronchodilators beta-agonistsanticholinergics, systemic steroids, and intravenous magnesium sulfate if the FEV125 predicted. The primary efficacy endpoint will be the FEV1 4 hours after administration of the study intervention. An additional safety and efficacy endpoint will take place at 5 hours after study intervention. The treatments will be coupled with a protocol-defined assessment regimen, with endpoints measured before each treatment and on ED disposition at 5 hours after study intervention. 