[Lung volumes in non-smoking healthy men in Maracaibo, Venezuela]

The significant applicability of the tests to measure lung volumes makes it necessary to handle them frequently and this implies the comparison of the registered values for lung function parameters with predicted or referential values which are obtained via derivate equations of healthy population studies. The Slow Vital Capacity (SVC), Inspiratory Capacity (IC), Functional Residual Capacity (FRC), Residual Volume (RV), Total Lung Capacity (TLC) and the physical characteristics, were measured in 50 healthy men, non smokers, with ages between 17 and 63 years, in order to deduce++ prediction equations. The functional tests were performed by means of the multiple respiratory technique and Helium Dilution, using a Spinnaker TL Lung Functions Analyzer. Stepwise multiple regression analyses were used to derive equations for predicting lung volumes, that allowed the inclusion of the variables that add prediction with statistical significance (95% of confidence), and obtaining for SVC: R = 0.853, SEE = 0.350 lts; IC: R = 0.822, SEE = 0.296 lts; FRC: R = 0.843, SEE = 0.326 lts; RV: R = 0.891, SEE = 0.153 lts y TLC: R = 0.883, SEE = 0.458 lts. The analysis of variance (ANOVA) was highly significant (p < 0.00001) for each one of the models of regression of the estimated parameters. The fifth percentile was considered as the lower limit of the established volume as the normal value. The calculation of fifth percentiles determined were SVC = 3.59 lts, IC = 2.47 lts, FRC = 2.14 lts, RV = 1.26 lts, and TLC = 4.88 lts. Those values can represent the levels under which the test are considered as reduced. Values which are equal o greater can be considered as "normal" for each one of the parameters studied. The equations of prediction for the SVC, IC, FRC, RV and TLC can be utilized with validity and high confidence to calculate reference static lung volumes in our population (p < 0.00001).