Measurement of Hemodynamic Variables Under Spinal Anesthesia With Varied Positioning

Multiple studies have compared spinal anesthetic performed supine versus lateral, with varying results, in parturients having elective cesarean section. Needle positioning during spinal placement has also been examined. No positioning techniques have demonstrated definitive superiority for hemodynamic stability. Investigators propose that following spinal placement in the sitting position if the patient is placed in a lateral position for 90 seconds prior to turning them supine, hemodynamic changes caused by sympathectomy related to the subarachnoid block can be avoided. This is the first study to examining the influence of position changes after spinal anesthetic placement in the sitting position, which includes hemodynamic variables not previously studied including cardiac output, TPR (total peripheral resistance) and pulse pressure variation (PPV).