[The evaluation of incremental positive end-expiratory pressure on right ventricular hemodynamics as determined by...

Effects of incremental positive end-expiratory pressure (PEEP) on right ventricular (RV) hemodynamics were studied in 10 patients undergoing coronary artery bypass grafting, abdominal aneurysmectomy and partial hepatectomy, using Swan-Ganz catheter mounted with the rapid response thermistor. PEEP was increased from 0 (baseline) to 15 cmH2O with increment of 5 cmH2O, and right ventricular ejection fraction (RVEF), RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), and cardiac output (CO) were computed with a thermodilution technique at each PEEP. At 15 cmH2O PEEP, RVEF, RVEDVI and RVESVI were comparable with the baseline, while right arterial pressure, RV peak systolic pressure and mean pulmonary arterial pressure increased significantly compared with the baseline. Increased afterload of RN caused by PEEP did not affect RV contractility. Decreased cardiac and stroke volume indices were attributed to the decrease of preload caused by the increase of intrathoracic pressure. We conclude that PEEP at 5 to 15 cmH2O does not influence right ventricular hemodynamics, and RVEDV is a reliable index to monitor RV hemodynamics instead of right arterial pressure to determine optimal PEEP.