Effect of Cromoglycate on Gas Changes, During Bronchial Challenge by UNCDW in Children with Asthma

[摘要] Eighteen asthmatic children were challenged with ultrasonicallynebulized cold distilled water (UNCDW). Blood gas composition wasmonitored transcutaneously (tcpO2and tcpCO2)during and after the challenge. Assuming as basal the response tothis UNCDW test, nine children (Group A) were then chosen at randomto inhale cromoglycate by aerosol delivery for 8 days. Nine children(Group B), acting as a control, inhaled saline for 8 days. At theend of this therapy, each child repeated the UNCDW test. Statisticalanalysis witht-test for paired data was used to compare the resultsof each child to both tests. Mean basal tcpO2andtcpCO2were all within the expected normal range. In allchildren, both mean tcpO2and tcpCO2werereduced during and after UNCDW inhalation. Mean tcpCO2values during the challenge were significantly (p<0.001) lower than the corresponding steady state 2 rain after the UNCDWchallenge, with a mean drop of −7% (2.1 S.D.). MeantcpO2values remained significantly decreased(p<0.001) from the fifth mitt of the UNCDW challenge to the end of theobservation period, with a mean drop of −20% (15.5S.D.). After treatment with cromoglycate (Group A), the meantcpCO2values during UNCDW did not change significantlyfrom those ofsteady state conditions: −0.8% (0.5 S.D.);whereas mean tcpO2values decreased by −4%(4.9 S.D.). The control children treated with saline (Group B)showed mean tcpCO2and tcpO2values which weresignificantly different (p<0.001) from those of the steadystate conditions: mean drop of tcpCO2, −6%(4.2 S.D.); mean drop of tcpO2, −20% (4.7S.D.). In conclusion, it emerges that: UNCDW induces nonspecificbroncho-constriction in asthmatic children with a typical drop oftcpCO2and tcpO2; the treatment withcromoglycate normalizes the time course of tcpCO2(hyper-reactivity) and reduces dramatically the drop oftcpO2time course (hyper-responsivity) during and afterthe UNCDW test.

[学科分类] 生理学与病理学