Comparison of Outcome Measures Pre- and Post-Treatment
Mean values for the study outcome measures recorded immediately prior to the study drug treatment and 30 minutes after treatment completion are summarized in Table 2. Average EF75 values improved with all study therapies, with statistically significant differences observed for saline placebo (3.9L/min ± 2.0 vs. 4.4L/min ± 2.4, p=0.04) and 1.25mg of albuterol (3.8L/min ± 1.7 vs. 4.5L/min ± 2.2, p<0.001). The differences for 2.5mg of albuterol approached but did fulfill the cutoff for significance (3.9L/min ± 1.9 vs. 4.2L/min ± 2.1, p=0.06). Among the secondary study outcomes, both dose levels of albuterol led to modest but statistically significant reduction in peak inspiratory pressure and increase in minute ventilation but were also associated with a small rise in average heart rate (Table 2). Of the 414 administered drug doses, 31 were associated with a greater than 20% post-treatment increase in heart rate. Stratified by drug therapy, 14% (19/132) of administered 2.5mg doses of albuterol were followed by a >20% rise in heart rate compared with 6% (8/144) of 1.25mg albuterol doses and 3% (4/138) of aerosolized saline treatments (p=0.001 for 3-way chi square comparison). All heart rate changes were self-limited and did not necessitate subsequent discontinuation of study drug therapy.