Accuracy of different indicators in predicting volume responsiveness in septic shock patients with myocardial depression: a comparison between lung ultrasound and PiCCO / 中华麻醉学杂志

ABSTRACT

Objective To compare the accuracy of the lung ultrasound and pulse indicator continuous cardiac output (PiCCO) in predicting volume responsiveness in septic shock patients with myocardial suppression.Methods Fifty patients of both sexes 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 injection or lactated Ringer's solution 500 ml was rapidly infused intravenously.PiCCO was used to monitor cardiac output,stroke volume,extravascular lung water index (EVLWI),pulmonary vascular penetration index (PVPI),intra-thoracic blood volume index and global end-diastolic volume index.The chest wall was scanned by ultrasound and the lung ultrasound score (LUS) was assessed.Positive fluid responsiveness was defined as an increase in PiCCO-monitored cardiac output＞ 10％ after fluid replacement.Patients were divided into positive fluid responsiveness group and negative fluid responsiveness group according to the results of fluid resuscitation test.The receiver operating characteristic (ROC) curve was drawn to evaluate the accuracy of each index in predicting fluid responsiveness.Results Compared with negative fluid responsiveness group,EVLWI,PVPI and LUS were significantly decreased,the number of patients in whom the bilateral anterior chest wall presented as B-line was increased in positive fluid responsiveness group (P＜0.01).The area under the ROC curve and 95％ confidence interval of LUS in predicting volume responsiveness was 0.836 (0.720-0.952),the cutoff value was 14.5 points,sensitivity 88％,and specificity 72％.The area under the ROC curve and 95％ confidence interval of EVLWI in predicting volume responsiveness was 0.818 (0.701-0.936),the cutoff value was 9.6 ml/kg,sensitivity 84％,and specificity 72％.The area under the ROC curve and 95％ confidence interval of PVPI in predicting volume responsiveness was 0.720 (0.575-0.865),the cutoff value was 1.55,sensitivity 92％,and specificity 52％.Conclusion The lung ultrasound and PiCCO produce higher accuracy in predicting volume responsiveness in septic shock patients with myocardial suppression;LUS has more advantages due to non-invasive examination.