Background Pediatric patients with croup are frequently admitted if they require two doses of racemic epinephrine(RE)in the emergency department(ED).We aimed to identify factors associated with the need for additional therapy(> 2 RE doses)among pediatric patients with croup.Methods We performed a single-center retrospective study of consecutive patients admitted from the ED with a diagnosis of croup between January 1,2011 and December 31,2015.Primary outcome was need for > 2 doses of RE.Secondary out-comes included time to third RE and 72-hour return visits.We performed logistic regression to identify factors associated with use of > 2 RE doses during hospitalization,and survival analysis to identify time to dosing of 3rd RE from 2nd RE.Results Of 353 included admissions [250(70.8%)males,median age 1.48,interquartile range 0.97-2.51 years],106/353(30.0%)required > 2 RE.In univariate logistic regression,only recent use of steroids within 1 day prior to presentation(4.18,1.48-11.83; P=0.007)was associated with need for>2 RE.Survival from third RE was 0.74(95%CI 0.69-0.78),which was similar to the survival at 12 hours(0.70,95%CI 0.65-0.75).Return visits occurred in 19(5.4%)patients,of whom 12/19(63.2%)were given RE.Conclusions Patients hospitalized for croup with recent use of steroids prior to ED presentation have a greater need for > 2 RE during hospitalization.The majority who require inpatient RE will do so within 8-12 hours.These data provide informa-tion for risk stratification and duration of monitoring for patients hospitalized with croup.