RESUMO
ABSTRACT: Background : Accurate prediction of fluid responsiveness is important for postoperative critically ill elderly patients. The objective of this study was to evaluate the predictive values of peak velocity variation (ΔVpeak) and passive leg raising (PLR)-induced changes in ΔVpeak (ΔVpeak PLR ) of the left ventricular outflow tract to predict fluid responsiveness in postoperative critically ill elderly patients. Method : Seventy-two postoperative elderly patients with acute circulatory failure who were mechanically ventilated with sinus rhythm were enrolled in our study. Pulse pressure variation (PPV), ΔVpeak, and stroke volume were collected at baseline and after PLR. An increase of >10% in stroke volume after PLR defined fluid responsiveness. Receiver operating characteristic curves and gray zones were constructed to assess the ability of ΔVpeak and ΔVpeak PLR to predict fluid responsiveness. Results : Thirty-two patients were fluid responders. The area under the receiver operating characteristic curves (AUC) for baseline PPV and ΔVpeak to predict fluid responsiveness was 0.768 (95% confidence interval [CI], 0.653-0.859; P < 0.001) and 0.899 (95% CI, 0.805-0.958; P < 0.001) with gray zones of 7.63% to 12.66% that included 41 patients (56.9%) and 9.92% to 13.46% that included 28 patients (38.9%). ΔPPV PLR predicted fluid responsiveness with an AUC of 0.909 (95% CI, 0.818-0.964; P < 0.001), and the gray zone was 1.49% to 2.93% and included 20 patients (27.8%). ΔVpeak PLR predicted fluid responsiveness with an AUC of 0.944 (95% CI, 0.863-0.984; P < 0.001), and the gray zone was 1.48% to 2.46% and included six patients (8.3%). Conclusions : Passive leg raising-induced changes in peak velocity variation of blood flow in the left ventricular outflow tract accurately predicted fluid responsiveness with a small gray zone in postoperative critically ill elderly patients.