Predicting and measuring fluid responsiveness with echocardiography

Abstract

Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart–lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid resuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Establishment of reference values of the caudal vena cava by fast‐ultrasonography through different views in healthy dogs

“…In human medicine, evaluation of inferior vena cava diameter (IVC D ) and collapsibility index (IVC CI ) as well as the ratio of IVC compared with the aortic diameter (IVC/Ao) all have been evaluated to assess intravascular volume status. Studies suggest they correlate well with dynamic variables of intravascular volume assessment and can predict fluid responsiveness in intensive care unit patients . The IVC D predicts volume status in spontaneously breathing healthy volunteers, in patients with severe sepsis, acute circulatory failure, and heart failure, in patients undergoing hemodialysis, and even in patients receiving positive pressure mechanical ventilation …”

Reference intervals and percentile curve for left ventricular outflow tract (LVOT), velocity time integral (VTI), and LVOT‐VTI‐derived hemodynamic parameters in healthy children and adolescents: Analysis of echocardiographic methods association and agreement

“…Available reports suggested that LVOT‐VTI assessment could be considered enough to monitor short‐term changes in SV. Furthermore, LVOT‐VTI would be an appropriate and dynamic indicator of fluid responsiveness …”

“…Furthermore, LVOT-VTI would be an appropriate and dynamic indicator of fluid responsiveness. 1,11 The measurements of LVOT and VTI-derived parameters have some advantages: (a) providing a CO surrogate that can be obtained easily and quickly with standard equipment widely available in health centers; (b) a good intra-and interobserver repeatability; 54…”

“…Changes in CO and left ventricle (LV) stroke volume (SV) could be quantified through PWD determinations using the velocity time integral (VTI) and the LV outflow tract (LVOT) diameter. LVOT‐VTI provides adequate information to follow changes in SV, and it has been proposed to be included in the Rapid Ultrasound in Shock protocol …”

“…1Changes in CO and left ventricle (LV) stroke volume (SV) could be quantified through PWD determinations using the velocity time integral (VTI) and the LV outflow tract (LVOT) diameter. LVOT-VTI provides adequate information to follow changes in SV, 1,9,[11][12][13] and it has been proposed to be included in the Rapid Ultrasound in Shock protocol. 9Despite the proven clinical usefulness of ultrasonic-derived CO indexes, there is lack of data regarding LVOT-VTI reference intervals (RIs), obtained from population-based studies in healthy people.…”