A few years ago, we studied the effects of high and cumulative doses of salbutamol and IB in the treatment of patients with acute severe asthma (ie, FEV1 <50% of predicted; n = 180).7
In a double-blind, randomized, controlled trial, we compared a regimen of salbutamol alone to salbutamol combined with IB (both drugs were administered through a metered-dose inhaler and spacer at rate of 4 puffs every 10 min). One hundred thirty patients (72% of total sample) had an FEV1 ≤ 30% of predicted. After 3 h of treatment, subjects who had received IB had an overall 20.5% greater improvement in peak expiratory flow and a 48.1% greater improvement in FEV1 compared with control subjects. The patients who were the most likely to benefit from the combined treatment were those with more severe obstruction (ie, FEV1 ≤ 30% of predicted). At the end of the protocol (3 h), there was a statistical reduction in the hospital admission rate. In Table 1
, we compared the FEV1 values from our study,7
(only patients with FEV1 ≤ 30% of predicted) with those of the Silverman et al,1
at arrival (0 min) and at the end of the protocol (our study, 180 min; Silverman et al, 240 min). The data showed the following: (1) similar baseline values in the two studies; (2) patients in our study who had received salbutamol and IB had significant FEV1 improvements at the end of the protocol in the three subgroups of patients, and, on the contrary, only patients with the lowest initial FEV1 (ie, < 20% of predicted) who had been treated with magnesium presented a significant improvement in pulmonary function; and (3) the ratio between the mean final differences of both studies favors our study in all subgroups studied.