Effect of Disodium Cromoglycate on Ventilation and Gas Exchange During Exercise in Asthmatic Children With a Postexertion FEVi Fall Less Than 15 Percent: Asthmatic Children
Pulmonary Function Tests: All children performed both tests without experiencing wheezing, cough, tightness of the chest or other respiratory complaints during and after the test. The results of lung function, expressed as percent of predicted, are presented in Table 1.
Exercise Testing Results: The exercise testing results are summarized in Table 2. During the run, Ve (Fig 1), V02, Vcc>2, and EC of running (Fig 2) were significantly lower in test В than in test A at comparable work rates (ANOVA, p <0.001). No differences between the two tests were found in peak V02 (test A, 40.7 ±6.7, and test B, 39.3 ±6.3 mb min • kg, p = not significant) and AT (test A, 29.4 ±4.9, and test B, 29.2 ±5.6 O2 ml • min • kg, p = not significant). The VEmax was lower under the premedicated condition (test A=46.9±14.6 and test B=43.2± 14.0 L-min, p <0.05).
The higher Ve in the test without premedication was sustained by an increase in tidal volume (ANO-VA, p <0.001), whereas respiratory rates were comparable in the two tests both at rest and during the run further buy antibiotics online.
The difference between the percentages of falls in FEVi for tests A and В was not correlated to the difference between the VEmax values of the two tests (r=0.18; p = not significant).
In both tests, pulmonary function was normal preexercise and post exercise. In test A, the values were as follows: FVC, 95.8 ±7.8 percent and 96.6 ± 7.2 percent of predicted, respectively (p = not significant); FEVi, 95.1 ±8.8 percent and 94.8±8.5 percent (p = not significant); FEF25-75%, 102.9 ± 16.4 percent and 98.3±16 percent (p = not significant). In test B, the same parameters preexercise and post exercise were: FVC,95.9±6.4 percent and 96.1 ± 6.2 percent (p = not significant); FEVi, 94.3 ±7.8 percent and 94.4 ±8.3 percent (p = not significant); FEF25-75%, 103.7 ±19.2 percent and 99.3 ±15 percent (p = not significant). The mean postexercise percentage of decrease in FEVi was 1.0 ± 2.0 percent and 1.2 ± 2.8 percent in tests A and B, respectively (p = not significant).
Table 1—Pulmonary Function Tests Before and After Treadmill Exercise Test in Asthmatic Children
|Pulmonary Function Tests||Test A (Baseline)||Test В (DSCG)||Probability Value ||
|FVC pretest||102.5± 11.9||101.9 ±12.0||NS|
|FVC posttest||102.1 ±12.1||103.4 ±12.2||NS|
|FEVi pretest||95.7 ±12.4||96.3 ±12.9||NS|
|FEVi posttestf||89.9 ±10.9||94.8 ±13.6||NS|
|FEF25-75% pretest||91.6±24.0||90.4 ±22.6||NS|
|FEF25-75% posttestf||84.6 ±22.5||92.1 ±25.8||NS|
|% FEVi fall||5.9±4.7||1.5±5.4||<0.01|
Table 2—Exercise Testing Results in Asthmatic Children
|Test A (Baseline)||Test В (DSCG)||Probability Value f|
|Resting V02, ml-min – kg||4.5 ±1.2||. 4.9± 1.5||NS|
|Resting Vco2, ml-min – kg||4.0±0.2||4.3 ±0.3||NS|
|Resting Ve, L-min||5.6± 1.7||6.0± 1.9||NS|
|AT,O2 ml-min-kg||29.4 ±4.9||29.2 ±5.6||NS|
|Peak V02,ml-min – kg||40.7 ±6.7||39.3 ±6.3||NS|
|VEmax,L-min||46.9 ±14.6||43.2 ±14.0||<0.05|
|Running time, min||8.2± 1.7||8.6± 1.6||NS|
|Maximal HR, beats per minute||195.9 ±9.1||196.9 ±8.1||NS|
Figure 1. Ventilation kinetics during incremental exercise in asthmatic children. The Ve was significantly lower in test test В (with DSCG premedication) than in test A (without premedication) at comparables work rates (p<0.001). The data are expressed as mean ± SE.
Figure 2. Energy cost of running in asthmatic children at corresponding work rates. The EC of running was higher in test A (without premedication) than in test В (with DSCG premedication) at comparable work rates (p<0.001). The data are expressed as mean ± SE.