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Updated: Mar 2, 2026
Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava
Published on: January 13, 2023
Inferior vena cava collapsibility detects fluid responsiveness among spontaneously breathing critically-ill patients
Keith A Corl1, Naomi R George2, Justin Romanoff3
1Department of Medicine, Division of Pulmonary Critical Care & Sleep, Alpert Medical School of Brown University, USA; Department of Emergency Medicine, Alpert Medical School of Brown University; School of Public Health of Brown University, Providence, RI, USA.
Purpose:
Measurement of inferior vena cava collapsibility (cIVC) by point-of-care ultrasound (POCUS) has been proposed as a viable, non-invasive means of assessing fluid responsiveness. We aimed to determine the ability of cIVC to identify patients who will respond to additional intravenous fluid (IVF) administration among spontaneously breathing critically-ill patients.
Methods:
Prospective observational trial of spontaneously breathing critically-ill patients. cIVC was obtained 3cm caudal from the right atrium and IVC junction using POCUS. Fluid responsiveness was defined as a≥10% increase in cardiac index following a 500ml IVF bolus; measured using bioreactance (NICOM™, Cheetah Medical). cIVC was compared with fluid responsiveness and a cIVC optimal value was identified.
Results:
Of the 124 participants, 49% were fluid responders. cIVC was able to detect fluid responsiveness: AUC=0.84 [0.76, 0.91]. The optimum cutoff point for cIVC was identified as 25% (LR+ 4.56 [2.72, 7.66], LR- 0.16 [0.08, 0.31]). A cIVC of 25% produced a lower misclassification rate (16.1%) for determining fluid responsiveness than the previous suggested cutoff values of 40% (34.7%).
Conclusion:
IVC collapsibility, as measured by POCUS, performs well in distinguishing fluid responders from non-responders, and may be used to guide IVF resuscitation among spontaneously breathing critically-ill patients.
