Accuracy of different parameters in predicting fluid responsiveness in septic shock patients with myocardial depression: a comparison between inferior vena cava ultrasound, PiCCO and CVP / 中华麻醉学杂志

ABSTRACT

Objective To compare the accuracy of inferior vena cava (IVC) ultrasound,central venous pressure (CVP) and pulse indicator continuous cardiac output (PiCCO) in predicting fluid responsiveness in septic shock patients with myocardial depression.Methods Fifty patients with septic shock complicated with myocardial depression,aged ＞ 18 yr,were enrolled in the study.The method for fluid replacement test was as follows0.9％ sodium chloride injectionor lactated Ringer's solution 500 ml was intravenously infused over 20 min,and positive fluid responsiveness was defined as an increase in PiCCO-monitored CO＞ 10％ after fluid replacement.Patients were divided into positive fluid responsiveness group and negative fluid responsiveness group according to the fluid replacement test.PiCCO was used to monitor stroke volume (SV),stroke volume variation (SVV) and pulse pressure variability (PPV) before fluid replacement,CVP was measured,and the diameter of IVC (d-IVC) and variability of IVC (v-IVC) were measured by bedside ultrasound.The receiver operating characteristic curve was drawn to evaluate the accuracy of each index in predicting fluid responsiveness.Results Compared with negative fluid responsiveness group,d-IVC was significantly decreased and v-IVC,SVV and PPV were increased before fluid replacement in positive fluid responsiveness group (P＜0.01).Three point five mmHg,14.5 mm,16.5％,17.0％ and 11.5％ were selected as the cutoff value for CVP,d-IVC,v-IVC,SVV and PPV,respectively.The sensitivity of CVP,d-IVC,v-IVC,SVV and PPV in predicting fluid responsiveness was 100％,92％,80％,44％ and 68％,respectively,and the specificity was 28％,80％,72％,100％ and 72％,respectively,and the area under the receiver operating characteristic curve (95％ confidence interval) was 0.609 (0.450-0.768),0.862 (0.750-0.974),0.777 (0.642-0.911),0.734 (0.596-0.873) and 0.733 (0.594-0.872),respectively.Conclusion PiCCO and IVC ultrasound provide higher accuracy in predicting fluid responsiveness in septic shock patients with myocardial depression,and IVC ultrasound is more superior because of non-invasive examination.