The association between pulsatile portal flow and acute kidney injury after cardiac surgery : a retrospective cohort study

Abstract

Objective:Venous congestion is a possible mechanism leading to acute kidney injury (AKI) following cardiac surgery. Portal veinflowpulsatility is an echographic marker of cardiogenic portal hypertension and might identify clinically significant organ congestion. Thisexploratory study aims to assess if the presence of portalflow pulsatility measured by transthoracic echography in the postsurgical intensive careunit is associated with AKI after cardiac surgery.Design:Retrospective cohort study.Setting:Specialized care university hospital.Participants:Patients who underwent cardiac surgery between May 2015 and February 2016 and had at least 1 Doppler assessment of portalflow performed by the attending critical care physician during the week following cardiac surgery.Interventions:The association between portalflow pulsatility defined as a pulsatility fractionZ50% and the risk of subsequent AKI wasassessed using univariate and multivariate logistic regression analysis.Measurements and Main Results:Thefiles of 132 consecutive patients were reviewed and 102 patients were included in the analysis. Significant portalflow pulsatility was detected in 38 patients (37.3%) in the week followingsurgery. During this period, 60.8% developed AKI and 13.7% progressed tosevere AKI. The detection of portalflow pulsatility was associated with an increased risk for the development of AKI (odds ration [OR] 4.31, confidenceinterval [CI] 1.50-12.35, p¼0.007). After adjustment, portalflow pulsatility and AKI were independently associated (OR 4.88, CI 1.54-15.47, p¼0.007).Conclusions:Assessment of portalflow using Doppler ultrasound at the bedside might be a promising tool to detect patients at risk for AKI dueto cardiogenic venous congestion.