In children with mild acute asthma, is albuterol (Salbutamol) delivered by a metered-dose inhaler (MDI) with a spacer (standard low dose or higher, weight-adjusted dose) as effective as albuterol delivered by a nebulizer?

Randomized, blinded, controlled trial in a hospital emergency department in Canada.

Participants were 90 children aged 5 to 17 years (mean: 9.2 years; mean baseline forced expiratory volume in 1 second [FEV₁]: 62.8%) who presented with acute asthma exacerbation between 8 AM and 10 PM, could reliably perform pulmonary function testing, and had a baseline FEV₁ of 50% to 79% of the predicted value. Exclusion criteria included the first wheezing episode, the use of albuterol within 4 hours, concurrent cardiopulmonary disease, and hypersensitivity to albuterol.

Thirty children were allocated to a standard low dose of albuterol by MDI with a clear plastic 140-mL spacer device with a mouthpiece (2 puffs, 100 μg per puff); 30 children were allocated to a higher, weight-adjusted dose of albuterol by MDI with a space (6-10 puffs [>100 μg per puff], depending on weight). The MDIs were shaken between each puff, and the children took five to six normal breaths through the mouthpiece between each puff. Thirty children were allocated to albuterol (0.15 mg/kg) by jet nebulizer with a tight-fitting mask. Albuterol mixed with 3 mL of normal saline solution was given by the nebulizer with an oxygen flow of 6 to 8 L/min over 15 to 20 minutes. To ensure patient blinding, each child used two MDIs and a nebulizer (the allocated treatment dose and two placebo doses).

Primary outcome was percentage of predicted FEV₁ measured with a handled spirometer. Secondary outcomes included respiratory rate, heart rate, oxygen saturation (room air), and scores for accessory muscle, wheezing, and dyspnea. Outcomes were assessed before treatment and 30, 60, and 90 minutes after treatment.

Analysis was by intention to treat. The three groups had similar mean changes from baseline to 90 minutes for FEV₁ (P=0.12), respiratory rate (P=0.98), oxygen saturation, and scores for accessory muscle (P=0.58), wheezing (P=0.73), and dyspnea (P=0.39). Children in the nebulizer group had a higher mean increase in heart rate than children in the two MDI groups (increase of 12.9 beats per minute vs 3.4 for high-dose MDI and 2.6 for low-dose MID; P=0.005). In children with mild acute asthma, a standard low dose of albuterol by MDI with a spacer was a effective as higher, weight-adjusted doses delivered by MDI with a spacer or low doses delivered by a nebulizer.