Outcomes/side effects	Albuterol (n = 64)	Levalbuterol (n = 65)
Median change in pulse rate*
After first nebulization	+8 bpm	+9 bpm
After third nebulization†	+21 bpm	+22 bpm
After fifth nebulization‡	+18 bpm	+18 bpm
Median change in respiratory rate*
After first nebulization	–2	–2
After third nebulization†	–4	–4
After fifth nebulization‡	–4	–5
Median change in pulse oximetry*
After first nebulization	+1	+1
After third nebulization†	+1	+1
After fifth nebulization‡	–1	+1
Side effects
Tremulousness	21 (33%)	24 (37%)
Nausea and vomiting	11 (17%)	5 (8%)
Headache	4 (6%)	8 (12%)
Lightheadedness	3 (5%)	9 (14%)
Decreased potassium levels (< 3.0 mEq per L [< 3.0 mmol per L])	3 (5%)	3 (5%)
Other§	1 (2%)	1 (2%)