ABSTRACT
Objective To assess the value of passive leg raising (PLR) combined with echocardiography in predicting volume responsiveness in patients with septic shock. Methods Thirty septic shock patients with spontaneous respiration admitted to intensive care unit (ICU) of Tianjin First Center Hospital from July 2016 to August 2018 were enrolled. PLR and volume expansion (VE) were performed successively. The hemodynamic parameters including left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), stroke volume (SV) and left ventricular ejection fraction (LVEF) before PLR (baseline level), after PLR, immediately after VE were examined by echocardiography, and the central venous pressure (CVP) was monitored. The patients with increase in SV after VE (ΔSV) ≥ 15% were served as reaction group, while ΔSV < 15% were served as non-reaction group. The changes in LVEDV, LVESV, SV, LVEF and CVP at baseline level, after PLR and after VE were compared between the two groups. Pearson correlation method was used to analyze the correlation between ΔSV, increase in LVEF (ΔLVEF) after PLR and ΔSV, and ΔLVEF after VE. Receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of ΔSV and ΔLVEF after PLR for volume responsiveness. Results PLR and VE were successfully performed in 30 patients, of which 23 patients (76.7%) were enrolled in the reaction group, and 7 patients (23.3%) in the non-reaction group. Compared with baseline levels, LVEDV, SV, and LVEF in the reaction group were significantly increased after PLR [LVEDV (mL): 83.5±9.6 vs. 77.1±6.2, SV (mL): 48.5±5.6 vs. 43.2±4.9, LVEF: 0.58±0.04 vs. 0.56±0.06, all P < 0.05], and CVP was significantly increased after VE [cmH2O (1 cmH2O = 0.098 kPa): 7.4±3.3 vs. 4.6±0.7, P < 0.01], however, there was no significant change in LVESV. In the non-reaction group, SV and LVEF were significantly increased after PLR as compared with those at baseline levels [SV (mL): 42.7±3.7 vs. 40.6±3.1, LVEF: 0.52±0.05 vs. 0.50±0.05, both P < 0.05], while LVEDV and CVP were significantly increased after VE as compared with those at baseline levels [LVEDV (mL): 84.4±4.1 vs. 80.6±5.9, CVP (cmH2O): 10.6±3.5 vs. 7.6±0.5, both P < 0.05], however, there was no significant change in LVESV. Pearson correlation analysis showed that ΔSV and ΔLVEF after PLR were positively correlated with ΔSV and ΔLVEF after VE (r1 = 0.86, r2 = 0.65, both P < 0.01). ROC curve analysis showed that the area under ROC curve (AUC) of PLR-induced ΔSV and ΔLVEF for predicting volume responsiveness was 0.85 and 0.66 respectively. When the cut-off value of ΔSV after PLR was 10.6%, the sensitivity was 78.2%, the specificity was 82.3%; when the cut-off value of ΔLVEF after PLR was 3.6%, the sensitivity was 78.2%, and the specificity was 73.2%. Conclusion ΔSV and ΔLVEF measured by PLR combined with echocardiography can be used to evaluate the volume responsiveness in patients with septic shock and can guide fluid therapy.