OBJECTIVE: To investigate predictive equations and normal values for maximal respiratory pressures available in the literature for children and adolescents. DATA SOURCES: Studies in English and Portuguese published from 1980 to 2009. Lilacs and Medline databases were consulted using the key-words "reference values", "respiratory muscles", "maximal respiratory capacity", "adolescent" and "child". DATA SYNTHESIS: Eight articles with a total of 1,463 adolescents and children were included in the review. The age of the studied population ranged from seven to 18 years old. The evaluations were usually performed with the patients in the sitting position with a nose clip. The variables were measured from residual volume and from total lung capacity and they were sustained for 1-3 seconds. Normal values and predictive equations were proposed in eight and two studies, respectively. These studies showed an increase in maximal respiratory pressures from childhood to adolescence and higher values of maximal expiratory pressure compared with maximal inspiratory pressure in children and adolescents of both genders. CONCLUSIONS: Maximal respiratory pressures are an effective way to assess respiratory muscle strength and several factors contribute to the wide variety of predictive equations and normal values available. Consensus to standardize the methods required to assess respiratory muscle strength in children and adolescents is needed.
muscle strength; respiratory muscles; reference values; adolescent; child
