Assessment of intravascular volume

Volume status and fluid responsiveness remain controversial topics in emergency and critical care (ECC). The concept of early stabilization using large volumes of isotonic crystalloid fluid boluses and/or colloids to improve tissue perfusion and oxygenation is common practice. However, not all hypovolemic patients will benefit from these large fluid volumes, particularly those with vasodilatory conditions or cardiac dysfunction. Furthermore, even in patients that demonstrate some improvement in cardiac output and tissue perfusion following fluid boluses, the deescalation and avoidance of overzealous crystalloid administration avoids destruction of the glycocalyx and helps to preserve the microcirculation. Therefore, the proper evaluation of fluid responsiveness is essential to help improve patient outcome even further. Monitoring of fluid status and fluid responsiveness is key to the management of all ECC patients requiring fluid therapy.