532 Maximum Expiratory Flow in Health Children from the Metropolitan Area of Monterrey Mexico

BACKGROUND: Studies have been conducted to obtain MEF (maximum expiratory flow) reference values in healthy children. Factors such as the region´s altitude, humidity, local temperature, and the characteristics of the study population cause changes in airway resistance that produce different MEF values. The objetive of this study is to establish normal reference values for MEF in healthy children from the metropolitan area of Monterrey, Nuevo Leon, Mexico and compare them with established reference values from other states of Mexico and the United States. METHODS: We carried out an observational, cross-sectional, descriptive, comparative study in healthy 6 to 8 year old children, both gender. A questionnaire that included information about age, weight, and height was applied. Flowmetry was performed with a Truzone portable peak flow meter and the highest of 3 values was recorded. RESULTS: We included 2282 children (1085 boys and 1197 girls) from 19 randomly selected elementary schools. The MEF values obtained were plotted on graphs in MEF percentiles according to gender and height. When compared with MEF reference values for authors from different locations, differences were found. CONCLUSIONS: The variation observed in MEF values in our population compared with studies performed in other populations shows the need for clinical demographic data from each region to establish and use characteristic reference values.