Assessment of Fluid Responsiveness by Elevation of PEEP in Patients With Septic Shock

The aim of the study is to evaluate whether fluid responsiveness of the critically ill patient can be assessed by analysing the PEEP-induced hemodynamic effects to systolic blood pressure, pulse pressure, aortic blood flow, aortic time-velocity integral and left ventricular end diastolic area measured with transesophageal echocardiography (PEEP-test). The chances are compared to increase of CI after volume expansion (gold standard). In clinical practise, it would be especially relevant if PEEP-induced changes in arterial pressure variations could be used in evaluation of volume status and fluid responsiveness. However, as ECHO-derived variables are used in greater extent to guide the treatment with inappropriate evidence, the simultaneous registration of ECHO-derived hemodynamic measurements is essential in the study design.