Rates of asthma are increasing in adults and children. In some pediatric institutions, asthma is the most common admitting diagnosis. At University of Chicago Children's Hospital (UCCH), at the University of Chicago Hospitals, the use of helium-oxygen mixtures (heliox) has been explored for treatment of children in status asthmaticus. Helium has a low density, and therefore has an increased flow rate which results in less airway resistance, decreased work of breathing, minimized airway collapse, and less hyperinflation. Little research on heliox and asthma has been done with children. A small study of children with status asthmaticus at the University of Chicago Children's Hospital found heliox resulted in improved peak flow readings and reductions in dyspnea and pulsus paradoxus. Nursing care of the child receiving heliox includes the use of appropriate delivery devices; monitoring temperature and other potential side effects; educating the child and family; and regularly assessing the following: pulse oximetry readings, heart and respiratory rates, blood pressure, and pulsus paradoxus.