Arterial Waveform Analysis Applying Different Positive End-Expiratory Pressure (PEEP) Levels in Healthy Volunteers

"four-step measurements of central artery blood pressure evaluating contour wave analysis during a progressive increasing of PEEP level First step (Baseline) Subjects spontaneously breathe in air at atmospheric pressure during applanation tonometry.~Second step (PEEP=5 cm H2O) Applanation tonometry was performed during the application of PEEP = 5 cmH2O (Oxygen flow = 8lt.- Air flow = 10 lt.).~Third step (PEEP= 10 cm H2O) Applanation tonometry was performed during the application of PEEP = 10 cmH2O (Oxygen flow = 15lt.- Air flow = 20 lt.).~Fourth step (Recovery) Subjects spontaneously rebreathe air at atmospheric pressure during applanation tonometry."