Study of Preoperative Blood Volume Optimization Using Echocardiography to Reduce Low Blood Pressure After Anesthesia Induction in Adults Undergoing Surgery

What this Trial Is About

Researchers are evaluating whether optimizing blood volume before surgery using transthoracic echocardiography TTE can reduce the incidence and severity of low blood pressure arterial hypotension following the start of general anesthesia. The study focuses on adult patients classified as ASA 3 or 4 who are undergoing intermediate or high-risk surgery. It is a prospective, randomized, controlled, double-blinded study comparing two approaches to stroke volume optimization during anesthesia induction. Participants are randomly assigned to either a standard care group, where stroke volume is optimized after anesthesia induction using an esophageal Doppler, or an experimental group receiving preoperative stroke volume optimization guided by TTE measuring the subaortic velocity time integral. Both groups undergo total intravenous anesthesia with drugs including propofol and remifentanil. Monitoring includes electrocardiogram, pulse oximetry, blood pressure via radial artery catheter, bispectral index for anesthesia depth, and neuromuscular blockade effects. Volume optimization involves guided administration of crystalloid fluids. During the study, patients undergo preoperative evaluation, including medical history and clinical exam, and a TTE either with or without volume optimization depending on their group. Data collected cover vital signs, stroke volume measurements, anesthesia drug dosing, blood pressure values, oxygen saturation, heart rate, and vasoactive drug use during anesthesia induction and 15 minutes afterward. The study ends shortly after this period and does not include long-term follow-up. The primary outcome is the occurrence of arterial hypotension mean arterial pressure below 65 mmHg within 15 minutes after intubation.

Preoperative Blood Volume Optimization Using Transthoracic Echocardiography