Intravascular volume status assessment still among the greatest significant obstacles in critical care management. The restrictions of invasive hemodynamic monitoring are being more apparent. Inferior vena cava (IVC), left internal jugular vein (IJV) collapsibility, pulmonary artery occlusion pressure (PAOP), central venous pressure (CVP), or left ventricular end diastolic area, as well as transpulmonary thermodilution index are all ways to evaluate body volume status. In recent years, the fluid status of a cases has been determined by the ultrasound-guided measurement of the inferior vena cava diameter and its variations with respiration. It is a comparatively cheap and also safe method. It may be employed as an alternative to central venous catheterization to evaluate the volume status of cases. The IVC-collapsibility index was demonstrated to be correlated with clinical and invasive assessments of intravascular volume status and has received increasing attention. It is simple to record and requires minimal training. Nevertheless, IVC measurement isn't achievable in ten to fifteen percent of cases because of obesity, raised intra-abdominal pressure, abdominal surgical dressings, huge amounts of intra-thoracic air, excessive intra-abdominal gas, extrinsic structures compressing IVC, elevated pulmonary artery pressure, tricuspid, or pulmonary valve disease.