OBJECTIVE: To verify the influence of crying and breathing patterns in the effectiveness of inhalatory therapy in children. DATA SOURCES: Systematic search of scientific studies on the subject in the Cochrane Controlled Trials Database, MedLine and Science Direct, published from 1994 to 2009. The descriptors "crying", "inhalation", "aerosol", "work of breathing" and "child", in Portuguese and in English, were applied. DATA SYNTHESIS: 13 studies were selected, 12 in English and one in Portuguese. Most studies reported the effects of inhalation therapy in children, without discussing the influence of crying and breathing patterns on the deposition of the medication. Studies related to this subject found that the respiratory pattern, especially the cry, reduces the amount of drug that reaches the peripheral airways. Authors discuss the anatomical and physiological differences between adults' and children's respiratory system that may interfere with the effectiveness of inhalation. However, most of them do not examine the qualitative and quantitative influence of the breathing patterns and crying on pulmonary mechanics. CONCLUSIONS: Crying and breathing patterns influence the inhalation therapy. The presence of cry significantly reduces the amount of drug deposition in the airways. There is insufficient evidence about the possible mechanisms that explain potential changes of inhalatory drugs deposition in children, despite its relevance to the management of pediatric pulmonary disorders.
inhalation; crying; work of breathing