Hemodynamic variations in arterial wave reflection associated with the application of increasing levels of PEEP in healthy subjects

Abstract

Positive end-expiratory pressure (PEEP) may affect arterial wave propagation and reflection, thus influencing ventricular loading conditions. The aim of the study was to investigate the hemodynamic variations in arterial wave reflection (i.e., wave reflection time, augmentation index, left ventricular ejection time, diastolic time, SEVR) associated with the application of increasing levels of PEEP in healthy subjects. We conducted a prospective observational study. Study population was selected from students and staff. Pulse contour wave analysis was performed from the right carotid artery during stepwise increase in PEEP levels (from 0 cmH₂O, 5 cmH₂0, 10 cmH₂O) with applanation tonometry. Sixty-two healthy volunteers were recruited. There were no significant changes in heart rate, augmentation index (AIx), left ventricular ejection time, Diastolic time (DT) among all of the different steps. A significant increase of time to the inflection point (Ti) was observed during all steps of the study. Diastolic area under the curve (AUC) divided by systolic-AUC (SEVR) increased from baseline to PEEP = 5 cmH₂O, and from baseline to PEEP = 10 cmH₂O. AIx and Ti were significantly correlated (directly) at the baseline and during PEEP = 10 cmH₂O. Ti and DT were significantly correlated at the baseline and during PEEP = 5 cmH₂O. In our preliminary results, low levels of PEEP played a role in the interaction between the heart and the vascular system, apparently mediated by a prolongation of the diastolic phase and a reduction in the systolic work of the heart.

Clinical trials registration number: NCT03294928, 19/09/2017.