Evaluation Of Volume Response Value In Patients With Septic Shock By Mechanical Ventilation Combined With Ultrasound

Objective:To evaluate the value of mechanical ventilation combined with ultrasound in evaluating the volume reactivity of patients with septic shock.Methods:A prospective cohort study was performed in 59 patients with septic shock who were admitted to the emergency intensive care unit of the First Affiliated Hospital of Xinjiang Medical University from October 2016 to February 2018.First,end-expiratory block test（EEO）and end-inhalation block test（EIO）were performed,followed by volume load test（VE）（intravenous infusion of 250 mL saline for 10 mins）,with CI increase after VE（ΔCI）≥15%divided into volume-responsive group（37 cases）and volume-free group（22 cases）,Vigileo-FloTrac system is used to continuously monitor EEO,EIO,and VE before and after changes in hemodynamic parameters,such as central venous pressure（CVP）,mean arterial pressure（MAP）,stroke volume variation（SVV）,and cardiac index（CI）,and improved inferior vena cava diameter（IVCD）and respiratory variability index（RVI）.The values of predicted capacity reactivity such as changes in CVP,MAP,SVV,CI,and RVI before and after EIO were evaluated,and the relationship between EEO,EIO,and capacity reactivity was analyzed by ROC curve.Results:There was no significant difference between MAP and CI in the response group and non-response group after EEO,EIO and VE intervention（P>0.05）.EEO-ΔSVV,EEO-ΔRVI,EEO-ΔCVP,EIO-ΔSVV and EIO-ΔRVI were compared between the reaction group and the non-reaction group,and the difference was statistically significant（P<0.05）;EEO-ΔRVI,EIO-ΔRVI and VE-ΔRVI was correlated（r=0.667,P<0.001;r=-0.442,P=0.001）;EEO-ΔCVP and VE-ΔCVP were correlated（r=0.391,P=0.002）;EEO-ΔSVV,EIO-ΔSVV and VE-ΔSVV have correlation（r=0.772,P<0.001;r=-0.604,P<0.001）;ROC curve shows EEO-ΔSVV,EEO-ΔRVI,EEO-ΔCVP,EIO-ΔSVV,EIO-ΔRVI The area under the ROC curve for in predicting volume responsiveness in patients with septic shock[AUC_EEO-ΔSVV=0.890,95%CI（0.792,0.988）],[AUC_EEO-ΔRVI=0.826,95%CI（0.712,0.939）],AUC_EEO-ΔCVP=0.738,95%CI（0.603,0.873）],[AUC_EIO-ΔSVV=0.800,95%CI（0.657,0.943）],[AUC_EIO-ΔRVI=0.767,95%CI（0.624,0.910）];There was no significant difference in the area under the curve of EEO-ΔSVV,EEO-ΔRVI,EEO-ΔCVP,EIO-ΔSVV,and EIO-ΔRVI（P>0.05）.Conclusion:EEO and EIO combined with ultrasound have certain clinical value in the evaluation of volume responsiveness in patients with septic shock,and the evaluation value of SVV and RVI is superior to other hemodynamic indicators.