This prospective observational study aims to evaluate the ability of transthoracic echocardiographic and bedside ultrasonographic parameters to predict intradialytic hypotension and hemodynamic instability at the initiation of continuous venovenous hemodiafiltration (CVVHDF) in adult intensive care unit patients.
In critically ill patients requiring renal replacement therapy, continuous venovenous hemodiafiltration (CVVHDF) is frequently preferred due to better hemodynamic tolerance. However, initiation of CVVHDF may still lead to unpredictable intradialytic hypotension, fluid requirement, or vasopressor/inotrope support. Bedside transthoracic echocardiography and ultrasonography provide non-invasive assessment of cardiac function, preload responsiveness, and venous congestion. Parameters such as left ventricular outflow tract velocity time integral (LVOT VTI), mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE), pulse pressure variation (PPV), renal resistive index (RRI), inferior vena cava (IVC) diameter, and venous excess ultrasound score (VExUS) may help predict hemodynamic tolerance to dialysis. This study aims to evaluate the predictive value of these multimodal ultrasonographic and hemodynamic parameters for intradialytic hypotension and hemodynamic support requirement during the first 60 minutes of CVVHDF initiation.
Study Type
OBSERVATIONAL
Enrollment
80
Hemodynamic Instability During CVVHDF Initiation
Occurrence of hypotension (mean arterial pressure \<65 mmHg), requirement for fluid bolus (≥500 mL), or initiation/increase of vasopressor or inotrope support within the first 60 minutes after CVVHDF initiation.
Time frame: First 60 minutes after CVVHDF initiation
LVOT Velocity Time Integral
Measurement of left ventricular outflow tract velocity time integral obtained by transthoracic echocardiography before dialysis initiation.
Time frame: Before CVVHDF initiation
Mitral Annular Plane Systolic Excursion (MAPSE)
Measurement of mitral annular plane systolic excursion obtained by M-mode transthoracic echocardiography in the apical four-chamber view to assess left ventricular longitudinal systolic function prior to CVVHDF initiation.
Time frame: Before CVVHDF initiation
Tricuspid Annular Plane Systolic Excursion (TAPSE)
Measurement of tricuspid annular plane systolic excursion obtained by M-mode transthoracic echocardiography in the apical four-chamber view to evaluate right ventricular systolic function prior to CVVHDF initiation.
Time frame: Before CVVHDF initiation
Pulse Pressure Variation (PPV)
Calculation of pulse pressure variation derived from invasive arterial blood pressure waveform analysis in mechanically ventilated patients to assess dynamic preload responsiveness prior to CVVHDF initiation.
Time frame: Before CVVHDF initiation
Renal Resistive Index (RRI)
Measurement of the Renal Resistive Index (RRI), obtained by pulsed-wave Doppler ultrasonography of the segmental or interlobar renal arteries, to evaluate intrarenal vascular resistance and renal perfusion prior to initiation of continuous veno-venous hemodiafiltration (CVVHDF). The Renal Resistive Index is calculated as (peak systolic velocity - end diastolic velocity) / peak systolic velocity, with values ranging from 0 to 1. Values greater than 0.7 are considered indicative of increased intrarenal vascular resistance and poorer renal perfusion (worse outcome).
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Time frame: Before CVVHDF initiation
Inferior Vena Cava Diameter
Ultrasonographic measurement of inferior vena cava diameter obtained from the subcostal long-axis view to assess intravascular volume status prior to CVVHDF initiation.
Time frame: Before CVVHDF initiation
Venous Excess Ultrasound Score (VExUS)
Assessment of systemic venous congestion using the Venous Excess Ultrasound Score (VExUS) prior to initiation of continuous veno-venous hemodiafiltration (CVVHDF). The Venous Excess Ultrasound Score is a grading system ranging from 0 to 3, incorporating inferior vena cava diameter and Doppler flow patterns of the hepatic, portal, and intrarenal veins. Higher scores indicate more severe systemic venous congestion and are associated with worse clinical status.
Time frame: Before CVVHDF initiation