Figure 1From: The caval index: an adequate non-invasive ultrasound parameter to predict fluid responsiveness in the emergency department? Relationship between the caval index and the change in systolic blood pressure after a fluid challenge. The horizontal line divides the study population in a group of responders and a group of non-responders. The vertical line represents the optimal threshold value for the caval index. Test characteristics: sensitivity 83%, specificity 67%, positive predictive value 48%, negative predictive value 92%.Back to article page