The role of ultrasonic cardiac output monitor in evaluating stroke volume variation to determine fluid responsiveness in patients with shock

Abstract

Background: Dynamic assessment of cardiac output (CO) with passive leg raise (PLR), stroke volume variation (SVV), and pulse pressure variation (PPV) offer effective and safe methods to predict fluid responsiveness in patients with shock. The primary aim of this study was to evaluate the reliability of CO and SVV readings with the ultrasonic cardiac output monitor (USCOM) 1A device compared to PPV measurements in determining fluid responsiveness of patients in shock. Materials and Method: Intubated and mechanically ventilated patients aged 18-95 with shock admitted to the medical intensive care unit from June 2019 to December 2020 were included in the study. Fluid responsiveness was assessed using PPV from arterial monitoring and CO/SVV using the USCOM 1A device. CO, PPV, and SVV data were recorded before and after PLR. Results: Out of 145 shock patients, 92 were included. Before the PLR maneuver, 67 patients had PPV values above 12% and were stated as fluid responsive. The SVV index measured by the USCOM device demonstrated good sensitivity (85%) and specificity (96%) in identifying fluid responsiveness. The agreement with PPV was substantial (Cronbach's alpha reliability: 0.718 [P < 0.001]), and the index was internally consistent (kappa agreement: 0.707 [P < 0.001]). The SVV index moderately correlated with PPV (R: 0.588 [P = 0.001]). Regarding fluid responsiveness determined by PPV, the AUC value of SVV was 0.797 (0.701-0.894) (p: 0.001). Conclusion: SVV measured by the USCOM device is a reliable and practical tool for hemodynamic assessment in clinical practice, particularly when invasive methods are unsuitable.