The effect of the prone position on venous pressure and blood loss during lumbar laminectomy

Study Objective: To determine the effects of three different prone support systems (Andrews spinal surgery frame, Cloward surgical saddle, and longitudinal bolsters) on inferior vena cava (IVC) and superior vena cava (SVC) pressures; the validity of measuring central venous pressure (CVP) for the determination of ideal positioning of the patient; and the relationship among frame type, blood loss, and hemodynamic measurements.