ObjectiveTo evaluate the value of stroke volume variation (SVV) and intrathoracic blood volume index (ITBVI) to predict fluid responsiveness in mechanically ventilated septic shock patients with spontaneous breathing. MethodsA prospective observational study was conducted in the Department of Critical Care Medicine of the First Affiliated Hospital of Guangzhou Medical University. Fluid resuscitation data was collected in septic shock patients who received PiCCO monitoring from June 2013 to June 2014. Transpulmonary thermodilution data were collected before and after fluid resuscitation, including cardiac index (CI), SVV, ITBVI, and central venous pressure (CVP). Seventeen patients were defined as responders by an observed increase of≥15% in the cardiac index (CI) after fluid resuscitation, 12 patients were defined as non-responders. Pearson correlation between changes of CI (ΔCI) and SVV, ITBVI, CVP was established. Area under the receiver operating characteristic (ROC) curve of SVV, ITBVI and CVP was calculated for predicting fluid responsiveness. ResultsBaseline CI and ITBVI were significantly lower in the responders (P < 0.05).There was no significant difference in baseline SVV between the responders and the non-responders (P > 0.05). A significant correlation was found between baseline ITBVI andΔCI (r=-0.593, P < 0.001), but no significant correlation between SVV andΔCI (r=0.037, P=0.847) or CVP andΔCI (r=0.198, P=0.302). The area under ROC curve of SVV, ITBVI and SVV for predicting fluid responsiveness was 0.640 (P=0.207), 0.865 (P=0.001), and 0.463 (P=0.565), respectively. The cut-off value of ITBVI for predicting fluid responsiveness was 784 mL/m2 with a sensitivity of 100.0% and a specificity of 70.6%. ConclusionIn mechanically ventilated septic shock patients with spontaneous breathing, ITBVI may be a valuable indicator in predicting fluid responsiveness compared with SVV.
ObjectiveTo evaluate the predictive value of mini-fluid challenge for volume responsiveness in patients under shock.MethodsSixty patients diagnosed as shock were included in the study. A 50 mL infusion of physiological saline over 10 seconds and a further 450 mL over 15 minutes were conducted through the central venous catheter. Cardiac output (CO), global end-diastolic volume index (GEDVI), central venous pressure (CVP) and extravascular pulmonary water index (EVLWI) were monitored by the pulse indicator continuous cardiac output monitoring. If the increase of CO after 500 mL volume expansion (ΔCO500) ≥10%, the patient was considered to be with volume responsiveness. The relevance between ΔCO50 and ΔCO500 was analyzed, and the sensitivity and specificity of the ΔCO50 were analyzed by receiver operating characteristic (ROC) curve.ResultsAfter 50 mL volume injection, the heart rate and systolic blood pressure of the two groups did not change obviously. The CVP of non-responders changed slightly higher than that of responders, but neither of them had obviously difference (P>0.05). The CO of responders had increased significantly (P<0.05) which was in accord with that after a further 450 mL volume injection. GEDVI and EVLWI did not change significantly (P>0.05). ΔCO50 and ΔCO500 were strongly correlated (r=0.706, 95%CI 0.677 - 0.891, P>0.05). The area under ROC curve for ΔCO50 was 0.814 (95%CI 0.707 - 0.922).ConclusionThe volume responsiveness of patients under shock can be predicted by mini-fluid challenge study which is related to normal volume expansion and it does not increase the risk of pulmonary edema.