Changes of the functional residual capacity due to application of positive end expiratory pressure and of continuous positive airway pressure ; Modificazioni della capacita funzionale residua (FRC) conseguenti all'applicazione di pressione positiva di fine espirazione (EPAP) e di pressione positiva continua (CPAP)

In 12 healthy subjects aged 25-33 years we measured FRC in spontaneous breathing after application of 5, 10, 15 cmH2O Positive End Expiratory Pressure (PEEP). The mean percent increase of FRC compared to basal levels was 19, 36, 39%. However, 3 subjects out of 12 did not modify FRC despite PEEP. In 12 subjects FRC was measured after 5, 10, 15 cmH2O PEEP and 5, 10, 15 cmH2O of Continuous Positive Airways Pressure (CPAP). The mean increase of FRC during PEEP was 13% for each 5 cmH2O, while during CPAP it was 18%. The CPAP appears to be more tolerated and effective than PEEP in increasing FRC.