Inferior vena cava collapsibility detects fluid responsiveness among spontaneously breathing critically-ill patients

J Crit Care. 2017 Oct:41:130-137. doi: 10.1016/j.jcrc.2017.05.008. Epub 2017 May 12.


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.

Keywords: Fluid responsiveness; Inferior vena cava collapsibility; Point-of-care ultrasound; Spontaneously breathing.

Publication types

  • Observational Study

MeSH terms

  • Administration, Intravenous
  • Adult
  • Aged
  • Critical Illness / therapy*
  • Female
  • Fluid Therapy / methods*
  • Humans
  • Male
  • Middle Aged
  • Point-of-Care Systems
  • Prospective Studies
  • Resuscitation / methods*
  • Ultrasonography / methods*
  • Vena Cava, Inferior / diagnostic imaging*
  • Vena Cava, Inferior / physiopathology