Fig. 2From: The assessment of circulating volume using inferior vena cava collapse index and carotid Doppler velocity time integral in healthy volunteers: a pilot studyRespiratory changes of IVC collapsibility and changes of stroke volume on passive leg raise. (a) Box plot illustrating change in IVC collapsibility index for quiet respiration and sniff on passive leg raise. (b) Box plot illustrating change in stroke volume on passive leg raiseBack to article page