Renal resistive index assessment by intraoperative transesophageal echocardiography is associated with acute kidney injury after cardiac surgery: a prospective observational study

Acute kidney injury (AKI) is a major health burden after cardiac surgery. Renal vasoconstriction and venous congestion can be assessed via transesophageal echocardiography (TEE). The primary objective is to determine feasibility of measuring intraoperative Renal resistive index (RRI) and portal vein pulsatility fraction (PF) by TEE. The secondary objectives are to determine the association between RRI and/or PF and postoperative AKI, Intensive Care Unit (ICU) length of stay, hospital length of stay, and 30-day mortality.