Assessing the venous system: Correlation of mean systemic filling pressure with the venous excess ultrasound grading system in cardiac surgery.

Abstract

Evaluation of the venous system has long been underestimated as an important component of the circulatory system. As systemic venous pressure increases, the perfusion pressure to the tissues is compromised. During initial resuscitation in cardiac surgery, excessive fluid administration is associated with increased morbidity and mortality. We conducted a cross-sectional study of 60 consecutive adult patients who underwent cardiac surgery and in whom it was possible to obtain the venous excess ultrasound (VExUS) grading system and mean systemic filling pressure (Pmsf) in the postoperative period upon admission, at 24 and 48h. We then determined the correlation between VExUS grading and Pmsf. On admission, patients with VExUS grading 0 predominated, with a progressive increase in venous congestion and an increase in Pmsf over the course of the first 48h. There was a strong positive correlation between VExUS grading and the invasive measurement of Pmsf at 24 and 48h after arrival. The presence of grade 2 or grade 3 venous congestion in the postoperative period poses an increased risk of developing acute kidney injury. The VExUS grading system indicates a high degree of systemic venous congestion in the first 48h of the postoperative period after cardiac surgery and correlates with the Pmsf, which is the best surrogate of stressed circulatory volume.