Association between Preoperative Retrograde Hepatic Vein Flow and Acute Kidney Injury after Cardiac Surgery

EARLY TRAJECTORY OF VENOUS EXCESS ULTRASOUND SCORE IS ASSOCIATED WITH CLINICAL OUTCOMES OF GENERAL ICU PATIENTS

ABSTRACT

Background: Systemic venous congestion, assessed by the venous excess ultrasound (VExUS) score, has been associated with adverse effects, including acute kidney injury (AKI), in patients with cardiac disease. In general intensive care unit (ICU) patients, the association between VExUS score and outcomes is understudied. We aimed to investigate the association between the trajectory of VExUS score within the first 3 days of ICU admission and the composite clinical outcome of major adverse kidney events within 30 days (MAKE30). Methods: In this prospective observational study, including patients consecutively admitted to the ICU, VExUS score was calculated within 24 h after ICU admission (day 1) and at 48 to 72 h (day 3). D-VExUS was calculated as the difference between the VExUS score on day 3 minus that on day 1. Development of AKI within 7 days and all-cause mortality within 30 days were recorded. Results: A total of 89 patients (62% men; median age, 62 years; median Acute Physiology and Chronic Health Evaluation II score, 24) were included. Sixty (67%) patients developed AKI within 7 days, and 17 (19%) patients died within 30 days after ICU admission. D-VExUS was associated with MAKE30, even after adjustment for confounders (hazard ratio, 2.07; 95% confidence interval, 1.17-3.66; P = 0.01). VExUS scores on days 1 or 3 were not associated with MAKE30. Also, VExUS scores on day 1 or on day 3 and D-VExUS were not associated with development of AKI or mortality. Conclusions: In a general ICU cohort, early trajectory of VExUS score, but not individual VExUS scores at different time points, was associated with the patient-centered MAKE30 outcome. Dynamic changes rather than snapshot measurements may unmask the adverse effects of systemic venous congestion on important clinical outcomes.

Development and validation of a nomogram for predicting intraoperative hypotension in cardiac valve replacement

Background: Cardiac valve replacement risks include intraoperative hypotension, endangering organ perfusion. Our nomogram predicted hypotension risk in valve surgery, guiding early intervention. Methods: Analyzing 561 patients from July to November 2022, we developed a nomogram to predict hypotension in valve replacement patients, validated using data from December 2022 to January 2023 on 241 patients, with robust statistical confirmation. Results: Our study identified age, hypertension, left ventricular ejection fraction and serum creatinine as hypotension predictors. The resulting nomogram, validated with high concordance index and area under the curve scores, provided a clinically useful tool for managing intraoperative risk. Conclusion: For valve replacement patients, factors like age, hypertension, low left ventricular ejection fraction and high serum creatinine predicted hypotension risk. Our nomogram enabled clinicians to quantify this risk and proactively manage it.

Diagnosis, pathophysiology and preventive strategies for cardiac surgery-associated acute kidney injury: a narrative review

Acute kidney injury (AKI) is a common and serious complication of cardiac surgery and is associated with increased mortality and morbidity, accompanied by a substantial economic burden. The pathogenesis of cardiac surgery-associated acute kidney injury (CSA-AKI) is multifactorial and complex, with a variety of pathophysiological theories. In addition to the existing diagnostic criteria, the exploration and validation of biomarkers is the focus of research in the field of CSA-AKI diagnosis. Prevention remains the key to the management of CSA-AKI, and common strategies include maintenance of renal perfusion, individualized blood pressure targets, balanced fluid management, goal-directed oxygen delivery, and avoidance of nephrotoxins. This article reviews the pathogenesis, definition and diagnosis, and pharmacological and nonpharmacological prevention strategies of AKI in cardiac surgical patients.

Special Issue on "Advances in Image-Guided Diagnosis and Treatment of Abdominal Diseases"

This Special Issue is a collection of five scientific papers and five reviews concerning current topics in abdominal imaging with attention on the diagnosis and interventional management of specific diseases [...].

Association between Hepatic Venous Congestion and Adverse Outcomes after Cardiac Surgery

INTRODUCTION

Hepatic venous flow patterns reflect pressure changes in the right ventricle and are also markers of systemic venous congestion. Fluid management is crucial in patients undergoing cardiac surgery.

METHODS

Our goal was to determine which factors are associated with the increased congestion of the liver as measured by Doppler ultrasound in patients undergoing cardiac surgery. This prospective, observational study included 41 patients without preexisting liver disease who underwent cardiac surgery between 1 January 2021 and 30 September 2021 at a tertiary heart center. In addition to routine echocardiographic examination, we recorded the maximal velocity and velocity time integral (VTI) of the standard four waves seen in the common hepatic vein (flow profile) using Doppler ultrasound preoperatively and at the 20-24th hour of the postoperative period. The ratios of the retrograde and anterograde hepatic venous waves were calculated, and the waveforms were compared to the baseline value and expressed as a delta ratio. Demographic data, pre- and postoperative echocardiographic parameters, intraoperative variables (procedure, cardiopulmonary bypass time), postoperative factors (fluid balance, vasoactive medication requirement, ventilation time and parameters) and perioperative laboratory parameters (liver and kidney function tests, albumin) were used in the analysis.

RESULTS

Of the 41 patients, 20 (48.7%) were males, and the median age of the patients was 65.9 years (IQR: 59.8-69.9 years). Retrograde VTI growth showed a correlation with positive fluid balance (0.89 (95% CI 0.785-0.995) c-index. After comparing the postoperative echocardiographic parameters of the two subgroups, right ventricular and atrial diameters were significantly greater in the "retrograde VTI growth" group. The ejection fraction and decrement in ejection fraction to preoperative parameters were significantly different between the two groups. (p = 0.001 and 0.003). Ventilation times were longer in the retrograde VTI group. The postoperative vs. baseline delta VTI ratio of the hepatic vein correlated with positive fluid balance, maximum central venous pressure, and ejection fraction. (B = -0.099, 95% CI = -0.022-0.002, p = 0.022, B = 0.011, 95% CI = 0.001-0.021, p = 0.022, B = 0.091, 95% CI = 0.052-0.213, p = 0.002, respectively.) Conclusion: The increase of the retrograde hepatic flow during the first 24 h following cardiac surgery was associated with positive fluid balance and the decrease of the right ventricular function. Measurement of venous congestion or venous abdominal insufficiency seems to be a useful tool in guiding fluid therapy and hemodynamic management.