Clinical Research Directory

Venous Excess and Lung Ultrasound During Continuous Kidney Replacement Therapy in Critically Ill Patients

Hemodynamic management of critically ill patients has long been focused on the arterial side of the vasculature by assessing adequate perfusion pressure. However, the venous pressure is also of critical importance. Venous congestion can occur in patients with right ventricular failure, pulmonary hypertension or fluid overload. Fluid overload has harmful effects to end organs causing acute kidney injury (AKI), lung edema, multiorgan dysfunction and death. Vice versa, AKI can aggravate fluid retention and inflammation. The measurement of venous pressure usually relies on central venous pressure (CVP) and inferior vena cava diameter (IVC). However, CVP measurement has been associated with measurement errors and has low accuracy in predicting fluid responsiveness. Moreover, IVC collapsibility or distensibility is a static parameter and is associated with subjective variability. Multiorgan Point-of-Care ultrasound (POCUS) can enhance the management of AKI by enabling the evaluation of renal structural abnormalities and hemodynamic status . POCUS allows the clinician to assess intravascular and pulmonary fluid overload. It has been shown that POCUS is a good parameter to predict global fluid status of the patient . Venous Excess Ultrasound (VEXUS) consists of the evaluation of IVC, hepatic vein, portal vein and intrarenal vein flow pattern. Previous studies showed significant correlation between VExUS score with RRT-free days and guide fluid management in critically ill patients with AKI . VExUS is useful in predicting patients at risk to develop AKI post cardiac surgery . Adding modified lung ultrasound score to the VExUS protocol could help clinician to adjust fluid administration and achieve proper fluid balance during continuous kidney replacement therapy (CKRT). However, the role of using combined VExUS and lung ultrasound in the assessment and guidance of fluid management during CKRT is unknown.