Evaluation of perioperative vascular volume with diameter and variation of the vein measured with ultrasound

Background Intravascular volume status is an essential parameter to evaluate quality of perioperative management and to prevent perioperative hemodynamic dysfunction. However, the accurate and reproducible estimation of this parameter is challenging. Ultrasound as a noninvasive examination technique can provide fast and objective assessment of the vascular volume status of patients. Because of its recognized advantages over invasive techniques, ultrasound has been widely used in perioperative surveillance. Objective This article reviews the application of ultrasound in perioperative monitoring of vascular volume status. Content In clinical investigation, ultrasound has been used to measure the diameter and collapse index of several veins, including inferior vena cava (IVC), subclavian vein (SCV), superior vena cava (SVC), internal jugular vein (IJV), and femoral vein (FV), and these parameters can often provide accurate estimation of volume status and volume resuscitation reaction. However, mechanical ventilation, obese, accumulation of gas in gastrointestine tract, abdominal injury, edema, etc, may incur difficulties in accurately measuring the diameter of IVC. In patients with pneumothorax and emphysema, SCV may not be clearly imaged. As IJV and FV are superficial, their shapes can be variable upon compression. Trend Ultrasound allows non-invasive perioperative monitoring of hemodynamics. To obtain reliable estimation of vascular volume, one should integrate information acquired from several veins. Key words: Ultrasound; Perioperative; Volume status