Effectiveness of the Aeroneb in Acute Severe Asthma

* Patients presenting with acute severe asthma exacerbations to the emergency room will be screened by the PI, co-investigator or research coordinator to determine their eligibility based on the inclusion and exclusion criteria. * Clinically indicated treatment must not be delayed for a research-related reason so patients will still be eligible for enrollment after receiving initial bronchodilator therapy as long as their PEFR remains \<50% of predicted and enrollment occurs within 90 minutes of the ER arrival time. * The initial part of the consent process will cover the essential elements of the informed consent in a concise manner to ensure a timely process * Eligible patients will be randomized using the concealed envelope method to either the intervention arm or the control arm. The randomization should take place within 90 minutes of ER arrival, however, every effort will be made to enroll the patient as soon as possible; patients will be enrolled as long as their PEFR is less than 50% of predicted regardless of the number of bronchodilator treatments they received prior to randomization. * The assignment will be blinded to the recording investigator and the treating physician but not to the patient or the nurse or respiratory therapist who is administering the nebulization. In order to avoid any delay in administering the treatments, the sets of Aeroneb nebulizer and small volume jet nebulizer will be stored in identical boxes and will be readily available in the ER. In order to blind the treating physician and the recording investigator, a sign "treatment in progress" will be displayed at the outdoor of the ER room when the patient is getting the bronchodilator treatment. The nebulizer devices will be placed in the box between the bronchodilator treatment sessions. The physician and the recording investigator will be asked if possible to see the patients only when the sign is taken off the outdoor. * Once assigned, all the bronchodilator treatments in the ER will be administered using the nebulizer device assigned to that patient. * The Peak flow and FEV1 will be measured using Spirometer (micro I). Both values will be obtained through the same exhalation maneuver. * Patient will be treated and managed according to the asthma ER adult protocol or as directed by the ER physician who is in charge of patient's care * After the study procedures have been performed and the subject is determined to be in stable condition and have the capacity to make medical decisions, the investigator will approach the subject again and review all the elements of the ICF again with the subject. The collected data will be used only if the subject signs both parts of the informed consent. * Within two weeks of the subject participation, the research team will conduct a phone interview with the subject to obtain their feedback on the study procedures and mainly on the informed consent process. The phone interview questionnaire is included in the supplement