The OPVI trial – perioperative hemodynamic optimization using the plethysmographic variability index in orthopedic surgery: study protocol for a multicenter randomized controlled trial

Background Hemodynamic optimization during surgery is of major importance to decrease postoperative morbidity and length of hospital stay. However, conventional cardiac outputmonitoring is rarely used at the bedside. Recently, the plethysmographicvariability index (PVI) was described as a simplified alternative, using plug-and- playnoninvasive technology, but its clinical utility remains to be established.