Cold air and exercise challenge- Influence of minute ventilation

TY - JOUR

T1 - Cold air and exercise challenge- Influence of minute ventilation

AU - Sylvester, K P

AU - O'Connor, B J

AU - Farebrother, H M

AU - Rafferty, G F

AU - Greenough, A

PY - 2007/3

Y1 - 2007/3

N2 - Exercises testing and cold air challenges are frequently used to assess airway hyperresponsiveness (AHR), but different goals are set for the two tests. We, therefore, wished to determine whether cold air and exercise challenge testing yielded similar responses and if any differences were due to differences in the maximum minute ventilation achieved. Twenty asthmatic subjects each performed a cold air (CACh) and an exercise (EXCh) challenge. Baseline forced expiratory volume in one second (FEV1) was recorded immediately pre-challenge and then serially for at least 10 minutes post-challenge. The maximum minute ventilation achieved was recorded. In the subjects who had at least a decrease in FEV1 of 15% in response to the first CACh, a second CACh was performed, but at the maximum minute ventilation achieved during EXCh. Eleven subjects after CACh and four after EXCh had a greater than 15% decrease in FEV1 (p = 0.05). The median decrease in FEV1 was greater following the CACh (16.7%[25th to 75th percentile 10.4 to 19.9]) than the EXCh (6.9%[25th to 75th percentile 4.3 to 14.6]); (p = 0.0004). The median maximum minute ventilation achieved was greater with the CACh (89[66-141] L/min) than with the EXCh (61(40 to 102)L/min); (p <0.0001). Only one of seven subjects who had previously responded to the CACh had a 15% decrease in FEV1 when the CACh was repeated at the same maximum minute ventilation achieved during EXCh (p = 0.007). In conclusion, cold air and exercise challenges do not produce the same response. Our results highlight than an explanation is the differences in the maximum-minimum ventilation achieved

AB - Exercises testing and cold air challenges are frequently used to assess airway hyperresponsiveness (AHR), but different goals are set for the two tests. We, therefore, wished to determine whether cold air and exercise challenge testing yielded similar responses and if any differences were due to differences in the maximum minute ventilation achieved. Twenty asthmatic subjects each performed a cold air (CACh) and an exercise (EXCh) challenge. Baseline forced expiratory volume in one second (FEV1) was recorded immediately pre-challenge and then serially for at least 10 minutes post-challenge. The maximum minute ventilation achieved was recorded. In the subjects who had at least a decrease in FEV1 of 15% in response to the first CACh, a second CACh was performed, but at the maximum minute ventilation achieved during EXCh. Eleven subjects after CACh and four after EXCh had a greater than 15% decrease in FEV1 (p = 0.05). The median decrease in FEV1 was greater following the CACh (16.7%[25th to 75th percentile 10.4 to 19.9]) than the EXCh (6.9%[25th to 75th percentile 4.3 to 14.6]); (p = 0.0004). The median maximum minute ventilation achieved was greater with the CACh (89[66-141] L/min) than with the EXCh (61(40 to 102)L/min); (p <0.0001). Only one of seven subjects who had previously responded to the CACh had a 15% decrease in FEV1 when the CACh was repeated at the same maximum minute ventilation achieved during EXCh (p = 0.007). In conclusion, cold air and exercise challenges do not produce the same response. Our results highlight than an explanation is the differences in the maximum-minimum ventilation achieved

U2 - 10.1080/02770900601182525

DO - 10.1080/02770900601182525

M3 - Article

VL - 44

SP - 143

EP - 147

JO - Journal of Asthma

JF - Journal of Asthma

IS - 2

ER -