Ventilated patients
IVC diameter predicts response to fluid therapy best in ventilated patients without spontaneous inspiratory effort.
distensibility index
(dIVC) = [(Dmax—Dmin) / Dmin] × 100
dIVC over 18% detects fluid respoders with a sensitivity and specificity of 90%.
respiratory variation on IVC diameter
ΔDIVC = [ (Dmax − Dmin) / [(Dmax + Dmin) / 2] × 100.
ΔDIVC of 12% distinguishes volume responders and non-responders with a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 92%
spontaneously breathing patients
(cIVC) = [(Dmax—Dmin) / Dmax] × 100
In this group a “collapsibility index” greater than 40–50% is suggests hypovolemia.
PMID: 40178737