Ultrasound-guided inferior vena cava collapsibility index as a predictor of fluid responsiveness in septic cancer patients

Abstract

Background & objective: Intravenous fluid therapy is a critical step in the resuscitation of patients suffering from sepsis and septic shock. Meticulous hemodynamic monitoring is necessary before as well as during the fluid therapy to avoid under- as well as over-loading the patient. An evaluation of fluid status has been suggested to be done non-invasively using the inferior vena cava collapsibility index (IVC-CI). We assessed the effectiveness of IVC-CI in evaluating septic patients' responses to fluid therapy at our institution. Methodology: Forty cancer patients with spontaneous breathing, who met sepsis criteria and were admitted to the intensive care unit, were included in this cross-sectional study. Over the course of three hours, the patients received crystalloids intravenously at a rate of 30 ml/kg, while CVP, ultrasonography guided IVC-CI measurement, and the vital sign monitoring was done every 30 min. Patients were divided into a responder group and a non-responder group based on a 10% change in cardiac output (CO) one hour later. IVC-CI variations in the volume responsiveness prediction served as the main outcome measure. Results: According to the change in CO one hour after starting fluid treatment, 29 patients (72.5%) were classified as fluid responsive and the remaining 11 (27.5%) as fluid non-responsive. In the two groups, HR and IVC-CI decreased significantly; whereas MAP, CVP, and CO increased significantly. ROC-curve analysis showed a percent change ≥ 3.4% of IVC-CI predicted positive responsiveness with a sensitivity of 72.4% and a specificity of 63.6%. These values were 79.3% and 72.7%, respectively, for a change ≥ 6.3% after one hour. The baseline value of IVC-CI was not predictive of responsiveness. Conclusion: In cancer patients with sepsis or septic shock, the change in inferior vena cava collapsibility index during the first hour of fluid therapy can predict fluid responsiveness with a moderate degree of accuracy.