The use of venous Doppler to predict adverse kidney events in a general ICU cohort

Abstract

Background Changes in Doppler flow patterns of hepatic veins (HV), portal vein (PV) and intra-renal veins (RV) reflect right atrial pressure and venous congestion; the feasibility of obtaining these assessments and the clinical relevance of the findings is unknown in a general ICU population. This study compares the morphology of HV, PV and RV waveform abnormalities in prediction of major adverse kidney events at 30 days (MAKE30) in critically ill patients. Study design and methods We conducted a prospective observational study enrolling adult patients within 24 h of admission to the ICU. Patients underwent an ultrasound evaluation of the HV, PV and RV. We compared the rate of MAKE-30 events in patients with and without venous flow abnormalities in the hepatic, portal and intra-renal veins. The HV was considered abnormal if S to D wave reversal was present. The PV was considered abnormal if the portal pulsatility index (PPI) was greater than 30%. We also examined PPI as a continuous variable to assess whether small changes in portal vein flow was a clinically important marker of venous congestion. Results From January 2019 to June 2019, we enrolled 114 patients. HV abnormalities demonstrate an odds ratio of 4.0 (95% CI 1.4–11.2). PV as a dichotomous outcome is associated with an increased odds ratio of MAKE-30 but fails to reach statistical significance (OR 2.3 95% CI 0.87–5.96), but when examined as a continuous variable it demonstrates an odds ratio of 1.03 (95% CI 1.00–1.06). RV Doppler flow abnormalities are not associated with an increase in the rate of MAKE-30 Interpretation Obtaining hepatic, portal and renal venous Doppler assessments in critically ill ICU patients are feasible. Abnormalities in hepatic and portal venous Doppler are associated with an increase in MAKE-30. Further research is needed to determine if venous Doppler assessments can be useful measures in assessing right-sided venous congestion in critically ill patients.

Clinical applications of the venous excess ultrasound (VExUS) score: conceptual review and case series

“…While VExUS will not likely provide much information on the need for fluid, it may provide stop points to fluid resuscitation and identify patients who are likely to tolerate and benefit from fluid removal. While the focus in fluid resuscitation has long been cardiac output or forward flow, the literature suggests strongly that venous congestion, as determined by CVP or by venous Doppler indices, will at a certain point offset the benefits of increasing said forward flow [4][5][6][7]16]. In fact, Vellinga et al, in studying the microcirculation, showed that a CVP above 12 actually resulted in a decreased tissue perfusion, and was associated with sluggish capillary flow which they termed "microcirculatory tamponade" [17].…”

FUSIC HD. Comprehensive haemodynamic assessment with ultrasound

“…The method adopted for FUSIC HD -the venous excess ultrasound (VExUS) score (see 23 High venous pressures first manifest on ultrasound as IVC dilatation, then as flow abnormalities in the great veins when assessed with PW Doppler. 24 The hepatic vein, portal vein and renal veins are key targets for assessment. Figure 2 illustrates normal and abnormal venous Doppler patterns.…”

Use of Ultrasound to Assess Hemodynamics in Acutely Ill Patients

“…Eventually, interstitial pressure exceeds arteriolar inflow. This effect is more prominent in encapsulated organs such as the kidneys (11), where increased venous pressure increases interstitial pressure leading to organ dysfunction and acute kidney injury (11,12). Patients in shock are particularly susceptible to kidney edema formation.…”

“…It often leads to pulmonary edema, which results in hypoxia and is frequently detected on plain x rays or oxygenation indicators like PaO2/FiO2. In contrast, identifying an increase in right atrial pressure is more challenging (12). Central venous pressure monitors and pulmonary artery catheters assess right atrial pressure.…”

“…Doppler flow patterns of hepatic veins (HV), portal vein (PV), and intra-kidney veins (iKV) are noninvasive and can identify early stages of right-sided venous congestion (15). Indeed, abnormal waveforms are associated with AKI in post-cardiac surgery patients (16,17) and may help predict early AKI in the general ICU population (12). In addition to Doppler flow patterns, other ultrasonography techniques are suggested to delineate the kidney hemodynamics, including contrast-enhanced ultrasonography (CEUS) (18) and ultrasound elastography (19).…”