[Oral steroids effects on the respiratory muscles function in severe asthmatic patients]. / Efeito da corticoterapia oral na função dos músculos respiratórios dos doentes com asma brônquica grave.

INTRODUCTION: Several studies suggest that severe asthmatic patients under oral steroids show higher risk of myopathy induced by steroids. Nevertheless, no conclusive data exist about the prolonged oral steroid therapy effects on the res- piratory muscles function. We didn't found correlation between the severity of obs- truction (evaluated by FEV1), hyperinflation (residual volu- me- RV) and the muscle pressures in both groups. Also, there were no significant correlation between the G1 PImax and oral steroid accumulated dose. CONCLUSION: We found a significant compromise of the res- piratory muscle function in the both studied groups with severe asthma. The oral steroid therapy caused no additional adverse effect in muscle respiratory function even after a prolon- ged treatment. The compromise of the muscle respiratory function foun- ded can be justified by the prolonged exposition to inhaled steroids. Key-words: Asthma, respiratory muscles, oral steroids.