Maximal respiratory pressure reference values for Navajo children ages 6-14

Background Since anthropometric variables are critical to the creation of pulmonary nomograms for FVC, FEV1, and other volumes and capacities, it is logical that anthropometric variables also influence the values of the maximal respiratory pressures (MRPs). Since nomograms are race-specific, it is important that tribe-specific tables of normal maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) be developed. To date normal tables for MRPs do not exist for Navajo children. Objective Therefore the purpose of this study was to derive MRP normative reference values for Navajo children in the age range of 6-14 years. Methods - Participants and Measurements A cross-sectional study was undertaken with a representative sample of 534 healthy children, ages 6-14 years, attending Navajo Nation elementary schools in Arizona. MIP and MEP were measured. Results Test results from 275 girls and 259 boys met American Thoracic Society quality control standards and showed that MRPs all increased with height. Mean MIP in cm H₂O was 77 for boys and 67 for girls with lower limits of 44 and 40, respectively. Mean MEP in cm H₂O was 75 for boys and 66 for girls with the lower limits of 42 and 38, respectively. Conclusion Since the data were collected from the population of interest, the resulting MIP and MEP reference equations should be used when testing Navajo children ages 6-14 years.