Bronchiolitis in Infants Placebo Versus Epinephrine and Dexamethasone Study

Two doses of oral dexamethasone, 0.6 mg/kg (maximum single dose 10 mg). One at the time of emergency department enrolment immediately prior to first nebulized treatment and one at approximately 24 hour later

Two nebulized treatments of 3 mL 1:1000 epinephrine 30 minutes apart (+/- 15 minutes) at the time of emergency department enrolment

Two doses of oral placebo, 0.6 mL/kg (maximum single dose 10 mL). One at the time of emergency department enrolment immediately prior to nebulized treatment and one at approximately 24 hour later . Oral placebo at Canadian sites is composed of OraBlendTM and in New Zealand and Australian sites will be a compounded solution.

Two nebulized treatments of 3 mL of normal saline 30 minutes apart (+/- 15 minutes) at the time of emergency department enrolment

Two doses of Epinephrine given by MDI plus spacer at 625 mcg (5 actuations of 125mcg) 30 minutes apart (+/- 15 minutes) at the time of emergency department enrolment.

Two doses of inhaled placebo given by MDI plus spacer, 30 minutes apart (+/- 15 minutes) at the time of emergency department enrolment.