Inclusion criteria:

1. Age 2-18 years
2. Prior diagnosis of asthma OR ED physician confirms this is an asthma exacerbation
3. For ages 2-17 years: LAR present at bedside for consent 

Exclusion criteria:

1. Cystic fibrosis or bronchopulmonary dysplasia
2. In law enforcement custody or wards of the state (i.e., DCF custody)
3. Known pregnancy
4. Critically ill (ESI triage level 1)
5. Intubated , on BiPAP, on CPAP, bag valve mask ventilation (“getting bagged”)