Figure 57-6 Changes in the cardiac index and systemic vascular resistance during laparoscopy in two groups of patients. For group 1 (controls, n = 10, filled bars), pneumoperitoneum was induced with patients in a 10-degree head-up position. Group 2 (volume loaded, n = 10, open bars) patients received 500 mL of lactated Ringer's solution before anesthesia induction and were insufflated in the supine position. Data are presented as the mean ± SEM.