lung ultrasound versus transpulmonary thermodilution in assessing extravascular lung water in septic shock after initial resuscitation

Abstract

Background: The prognostic value of extravascular lung water index (EVLWI) which is determined by transpulmonary thermodilution has been widely investigated. The aim of this study is to assess the prognostic value of lung ultrasound compared to transpulmonary thermodilution in assessing EVLW in septic shock. Materials & Methods: This is a prospective observational study where fifty adult patients of both genders with septic shock received initial fluid resuscitation and underwent continuous hemodynamic monitoring using pulse index continuous cardiac output (PiCCO) and simplified lung ultrasound protocol, analyzing the prognostic value of lung ultrasound score (LUS) compared to EVLWI in 48 hours after initial resuscitation. Results: With ICU mortality as the end point, 50 patients were divided into a survivor group (30 patients) and a non-survivor group (20 patients). LUS showed significant linear correlation with EVLWI (Spearman’s r=0.848, P=<0.001^* at T48). LUS and EVLWI were significantly higher in non-survivors than in survivors (P =<0.001^*at T48). The areas under the receiver operating characteristic curves of LUS and EVLWI measured by PiCCO were 0.843 and 0.921 at T48, respectively. The cut-off of LUS and EVLWI for prognosis prediction were 12 and 12.7, respectively. Pairwise comparison of both ROC curves showed no significant difference between LUS and EVLWI as predictors of mortality at T48, p =0.125. Conclusion: Lung ultrasound is a useful, simple, non-invasive tool for predicting the prognosis of septic shock patients compared to EVLWI measured by PiCCO.