Knowing when to give fluids to the patient is very important in fluid therapy.It is appropriate to administer it to patients whose cardiac output will increase when the fluid is administered (a patient with fluid responsiveness). Appropriate fluid administration can hemodynamically stabilize the patient's condition and reduce unnecessary fluid administration, thereby reducing complications that occur when fluid is insufficient or excessive fluid is administered.~The most commonly used dynamic variables in clinical practice are pulse pressure variation (PPV), stroke volume variation (SVV), and systolic pressure variation that can be obtained by invasive arterial tube insertion. However, recently a non-invasive monitoring method is being used in more and more areas, and in many cases it is necessary to closely monitor the patient's hemodynamic status without mounting an arterial catheter. Therefore, if the variables measured by a non-invasive method can predict fluid responsiveness at a reliable level, it will be of great help in clinical practice.~According to previous studies, dynamic variables can relatively accurately predict fluid responsiveness only in patients undergoing mechanical ventilation. However, in actual clinic, it is necessary to evaluate fluid reactivity even in patients who are not under mechanical positive pressure ventilation. Accurate fluid treatment should be performed during or after surgery under spinal anesthesia in the recovery room. In addition, there are cases in which dynamic variables must be monitored non-invasively in spontaneous breathing patients who do not undergo mechanical ventilation even in intensive care units.~It is clinically meaningful to predict fluid responsiveness in spontaneous breathing patients using such a non-invasive method of monitoring. However, there is limited data on how to evaluate fluid responsiveness in these patient groups. Therefore, the purpose of this study is to evaluate whether fluid responsiveness can be predicted in spontaneous breathing patients using non-invasive dynamic variables.
The purpose of this study is to find out if non-invasive dynamic parameters can predict fluid responsiveness in spontaneous breathing patients.