Is There Any Correlation Between Respiratory Variation Ratios of Internal Jugular Vein and Inferior Vena Cava?

IVC was visualized in the subxiphoid long axis by using convex probe (5-1 MHz). Diameters of IVC was measured 2 cm caudally to the junction of hepatic vein in M-mode. IJV diameter was measured in the short axis by using linear probe (12-5 MHz) and M-mode. IJV visualized in the junction of cricothyroid membrane level and midclavicular line. Maximum and minimum diameter values were measured in the M mode. Distensibility (maximum diameter - minimum diameter / minimum diameter) and collapsibility (maximum diameter - minimum diameter / maximum diameter) indices were calculated after USG measurements were done.