Impact of Positive End-Expiratory Pressure on Thermodilution-Derived Right Ventricular Parameters in Mechanically Ventilated Critically Ill Patients

• Published in: Journal of cardiothoracic and vascular anesthesia 2016-06, Vol.30 (3), p.632-638
• Main Authors: Cherpanath, Thomas G.V., MD, Lagrand, Wim K., MD, PhD, Binnekade, Jan M., PhD, Schneider, Anton J., MD, Schultz, Marcus J., MD, PhD, Groeneveld, Johan A.B., MD, PhD
• Format: Article
• Language: English
• Subjects: Aged; Anesthesia & Perioperative Care; cardiac output; Cardiac Output - physiology; Catheterization, Swan-Ganz - methods; Critical Care; Critical Illness - therapy; Female; Humans; Male; Middle Aged; Monitoring, Physiologic - methods; Pilot Projects; positive end-expiratory pressure; Positive-Pressure Respiration - methods; Prospective Studies; pulmonary artery catheter; right ventricle; Stroke Volume - physiology; stroke volume variation; thermodilution; Thermodilution - methods; Ventricular Function, Right - physiology
• ISSN: 1053-0770; 1532-8422
• DOI: 10.1053/j.jvca.2015.09.010

Objectives To examine the effect of positive end-expiratory pressure (PEEP) on right ventricular stroke volume variation (SVV), with possible implications for the number and timing of pulmonary artery catheter thermodilution measurements. Design Prospective, clinical pilot study. Setting Academic medical center. Participants Patients who underwent volume-controlled mechanical ventilation and had a pulmonary artery catheter. Intervention PEEP was increased from 5-to-10 cmH2 O and from 10-to-15 cmH2 O with 10-minute intervals, with similar decreases in PEEP, from 15-to-10 cmH2 O and 10-to-5 cmH2 O. Measurements and Main Results In 15 patients, right ventricular parameters were measured using thermodilution at 10% intervals of the ventilatory cycle at each PEEP level with a rapid-response thermistor. Mean right ventricular stroke volume and end-diastolic volume declined during incremental PEEP and normalized on return to 5 cmH2 O PEEP (p = 0.01 and p = 0.001, respectively). Right ventricular SVV remained unaltered by changes in PEEP (p = 0.26), regardless of incremental PEEP (p = 0.15) or decreased PEEP (p = 0.12). The coefficients of variation in the ventilatory cycle of all other thermodilution-derived right ventricular parameters also were unaffected by changes in PEEP. Conclusions This study showed that increases in PEEP did not affect right ventricular SVV in critically ill patients undergoing mechanical ventilation despite reductions in mean right ventricular stroke volume and end-diastolic volume. This could be explained by cyclic counteracting changes in right ventricular preloading and afterloading during the ventilatory cycle, independent of PEEP. Changes in PEEP did not affect the number and timing of pulmonary artery catheter thermodilution measurements.