Analysis of variance was used to compare quantitative variables at baseline and after the different treatments for each subject and to compare the percentage of change after each drug (S and IB). Paired t tests (two-tailed) were applied to compare the values after the additive treatment doses. A p value ^0.05 was considered to be significant.
Baseline characteristics of the patients as well as baseline pulmonary function measurements (PFTs), oxygen saturation, and heart rate are presented in Table 1. All patients had previous evidence of a positive response to inhaled S on at least 1 occasion in the previous 2 years. There was no difference in the average baseline PFT between the 2 days of the protocol.
There was a significant improvement in FEV\ and a decrease in Raw after inhalation of high doses of S during sequence A or IB during sequence В compared with baseline (Table 2). The improvement in midex-piratory flows was not statistically significant. Lung volume measurements (RV and FRC) were decreased by 10 and 5 percent vs 12 and 7 percent after S200 + S400 in sequence A compared to after IBW, in sequence B. However, these decreases were not significantly different from baseline. There was no significant further improvement in expiratory flows, lung volumes, and Raw when IB was given after high doses of S (sequence A) or when S was given after a high dose of IB (sequence B) (Table 2). The PFTs at 4 and 8 h from baseline showed a significant increase in FEVt (p<0.05) and a decrease in Raw (p<0.01) compared with baseline with either sequence. Expiratory flows and lung volume measurements were not significantly different from baseline. canadian family pharmacy online
The effect of bronchodilators on FE V! is shown in Figure 2. Both drugs induced a significant improvement when high doses were given, but there was no significant difference between the average percentage increase in FEV! of 13.9 ± 1.9 percent with S 200 + 400 \ig (90 min, sequence A) and 13.2 ± 1.0 percent with IB 80 |xg (45 min, sequence B). When one bronchodilator was added after the maximal dose of the other, the changes in FEVi were not significantly different from the initial improvement, both during sequence A and B. At 4 and 8 h after baseline measurements, FEVi was still significantly increased by 13.7 ±2.9 percent and 14.7 ±4.9 percent during sequence A vs 13.5 ±2.1 percent and 15.2 ±5.7 percent during sequence B.
The mean percentage decrease in Raw after S200+S400 was 25.6 ±3.9 percent (90 min), which was not significantly different from 28.2 ± 2.9 percent after IBso (45 min) (Fig 3). Thus, after the patients received the maximal dose of one bronchodilator, no further significant decrease in Raw was observed. At 4 and 8 h after baseline, Raw was reduced by 31.2 ±2.9 percent and 25.1 ±2.4 percent of baseline values during sequence A, vs 31.5 ±3.7 percent and 24.7± 5.8 percent during sequence B. Heart rate and oxygen saturation were not significantly different from baseline measurements throughout the protocol on either day. No subjective side effects were reported by any patient; in particular, no tremor or palpitations were noted. There was no significant correlation among age, baseline PFT, or Shwachman Kulczycki-score and response to p-adrenergic or anticholinergic bronchodilators.
Table 1—Baseline Characteristics of the Fatients
|Subject/Sex||Age,yr||Height,(cm)||Weight,kg||SK*||FEV„ % pred||FRC, % pred||Raw, % pred||SaOe,%||HR,bpm|
Table 2—Heart Bate, Oxygen Saturation, and Pulmonary Function Tests at Baseline and Following Inhalation of Salbutamol and Ipratropium Bromide (Mean±SE)
|HR,bpm||Sa02,%||FVC,L||FEV,,L||FEF50,Us||FEF25-75,Us||RV, L||FRC, L||Raw, cm H20/L/s|
|Sequence A Baseline||98±4||95±1||2.25 ±0.2||1.48±0.1||1.45±0.4||1.27±0.3||2.11 ±0.5||2.77 ±0.6||4.04 ±0.2|
|S*o||101 ±4||95± 1||2.30 ±0.2||1.64 ±0.1||1.74±0.4||1.49 ±0.3||2.03 ±0.5||2.83 ±0.6||3.16 ±0.2*|
|S400||102 ±5||95± 1||2.34 ±0.2||1.67±0.1t||1.75 ±0.4||1.52 ±0.3||2.04 ±0.5||2.81 ±0.6||2.98 ±0.2*|
|IB»||106 ±4||95± 1||2.35 ±0.2||1.70±0.1t||1.75 ±0.4||1.56±0.4||2.00 ±0.5||2.77 ±0.6||2.70 ±0.1*|
|4 h||103 ±5||94± 1||2.45 ±0.2||1.68±0.1t||1.75±0.4||1.52 ±0.4||1.88±0.4||2.66 ±0.5||2.75±0.1*|
|8 h||101 ±4||95 ± 1||2.41 ±0.2||1.69 ±0. It||1.73 ±0.4||1.51 ±0.3||1.91 ±0.5||2.69 ±0.6||3.02 ±0.2*|
|Sequence В Baseline||98±4||94± 1||2.14 ±0.2||1.42 ±0.1||1.49±0.4||1.26 ±0.3||2.22 ±0.6||2.87 ±0.6||4.00 ±0.3|
|IB»||96±3||95±1||2.22±0.2||1.60±0.1t||1.73±0.4||1.49 ±0.4||1.98±0.5||2.65 ±0.6||2.86 ±0.3*|
|S*J0||100±3||95± 1||2.32 ±0.2||1.63 ±0. it||1.79±0.4||1.53±0.4||1.94 ±0.5||2.65 ±0.6||2.66 ±0.1*|
|S«||105 ±4||94± 1||2.36 ±0.2||1.62 ±0. It||1.73 ±0.4||1.51 ±0.3||1.97 ±0.5||2.67 ±0.6||2.68 ±0.2*|
|4 h||103 ±5||95±1||2.28±0.2||1.60±0.1t||1.72±0.4||1.47 ±0.3||1.93 ±0.5||2.63 ±0.6||2.74 ±0.2*|
|8 h||95± 1||96±3||2.34 ±0.2||1.61±0.1t||1.77±0.4||1.54±0.4||1.90±0.5||2.68 ±0.6||2.97 ±0.2*|
Figure 2. Percentage of change in FEV, from baseline value during 8-h protocol, after the inhalation of different regimens of bronchodilators (sequence A or В as in Fig 1). Mean±SE percentage of change is shown for the group of patients each day.
Figure 3. Percentage of change in airway resistance from baseline value during the 8-h protocol after the inhalation of different regimens of bronchodilators (sequence A or В as in Fig 1). Mean ± SE percentage of change is shown for the group of patients each day.