Right ventricular function during positive end-expiratory pressure. Thermodilution evaluation and clinical application.

Right ventricular (RV) function was studied in 13 patients under controlled mechanical ventilation with positive end-expiratory pressure (PEEP) for adult respiratory distress syndrome. The assessment of RV function was made by the thermodilution technique. Calculations of RV ejection fraction (RVEF) and RV end-diastolic volume (RVEDV) were performed. In 11 patients, increasing PEEP was accompanied by a progressive decrease in blood pressure (BP), stroke volume (SV), RVEDV, and no change in RVEF. Increasing PEEP further was accompanied by a further decrease in RV preload. The remaining two patients exhibited a decrease in BP, SV, RVEF and an increase in RVEDV. One of these two patients exhibited a large decrease in cardiac output (CO). Thus, measurement of RVEDV (best parameter of ventricular preload) and RVEF are easily performed at the patient's bedside using a special thermodilution technique. This allows selection of the best treatment of PEEP-induced decrease in CO.