The value of a superior vena cava collapsibility index measured with a miniaturized transoesophageal monoplane continuous echocardiography probe to predict fluid responsiveness compared to stroke volume variations in open major vascular surgery: a prospective cohort study.

Superior vena cava collapsibility index (SVC-CI) and stroke volume variation (SVV) have been shown to predict fluid responsiveness. SVC-CI has been validated only with conventional transoesophageal echocardiography (TEE) in the SVC long axis, on the basis of SVC diameter variations, but not in the SVC short axis or by SVC area variations. SVV was not previously tested in vascular surgery patients. Forty consecutive adult patients undergoing open major vascular surgical procedures received 266 intraoperative volume loading tests (VLTs), with 500 ml of gelatine over 10 min. The hSVC-CI was measured using a miniaturized transoesophageal echocardiography probe (hTEE). The SVV and cardiac index (CI) were measured using Vigileo-FloTrac technology. VLTs were considered 'positive' (≥ 11% increase in CI) or 'negative' (< 11% increase in CI). We compared SVV and hSVC-CI measurements in the SVC short axis to predict fluid responsiveness. Areas under the receiver operating characteristic curves for hSVC-CI and SVV were not significantly different (P = 0.56), and both showed good predictivity at values of 0.92 (P < 0.001) and 0.89 (P < 0.001), respectively. The cutoff values for hSVC-CI and SVV were 37% (sensitivity 90%, specificity of 83%) and 15% (sensitivity 78%, specificity of 100%), respectively. Our study validated the value of the SVC-CI measured as area variations in the SVC short axis to predict fluid responsiveness in anesthetized patients. An hTEE probe was used to monitor and measure the hSVC-CI but conventional TEE may also offer this new dynamic parameter. In our cohort of significant preoperative hypovolemic patients undergoing major open vascular surgery, hSVC-CI and SVV cutoff values of 37% and 15%, respectively, predicted fluid responsiveness with good accuracy.

The Diagnosis and Hemodynamic Monitoring of Circulatory Shock: Current and Future Trends.

Circulatory shock is a complex clinical syndrome encompassing a group of conditions that can arise from different etiologies and presented by several different hemodynamic patterns. If not corrected, cell dysfunction, irreversible multiple organ insufficiency, and death may occur. The four basic types of shock, hypovolemic, cardiogenic, obstructive and distributive, have features similar to that of hemodynamic shock. It is therefore essential, when monitoring hemodynamic shock, to making accurate clinical assessments which will guide and dictate appropriate management therapy. The European Society of Intensive Care has recently made recommendations for monitoring hemodynamic shock. The present paper discusses the issues raised in the new statements, including individualization of blood pressure targets, prediction of fluid responsiveness, and the use of echocardiography as the first means during the initial evaluation of circulatory shock. Also, the place of more invasive hemodynamic monitoring techniques and future trends in hemodynamic and metabolic monitoring in circulatory shock, will be debated.

Pulse waveform hemodynamic monitoring devices: recent advances and the place in goal-directed therapy in cardiac surgical patients.

Hemodynamic monitoring has evolved and improved greatly during the past decades as the medical approach has shifted from a static to a functional approach. The technological advances have led to innovating calibrated or not, but minimally invasive and noninvasive devices based on arterial pressure waveform (APW) analysis. This systematic clinical review outlines the physiologic rationale behind these recent technologies. We describe the strengths and the limitations of each method in terms of accuracy and precision of measuring the flow parameters (stroke volume, cardiac output) and dynamic parameters which predict the fluid responsiveness. We also analyzed the place of the APW monitoring devices in goal-directed therapy (GDT) protocols in cardiac surgical patients. According to the data from the three GDT-randomized control trials performed in cardiac surgery (using two types of APW techniques PiCCO and FloTrac/Vigileo), these devices did not demonstrate that they played a role in decreasing mortality, but only decreasing the ventilation time and the ICU and hospital length of stay.