Impact of the patient's body position on the intraabdominal workspace during laparoscopic surgery

The effects of the patient's body position on the intraabdominal workspace in laparoscopic surgery were analyzed. The inflated volume of carbon dioxide was measured after insufflation to a preset pressure of 15 mmHg for 20 patients with a body mass index (BMI) greater than 35 kg/m(2). The patients were anesthetized with full muscle relaxation. The five positions were (1) table horizontal with the legs flat (supine position), (2) table in 20A degrees reverse Trendelenburg with the legs flat, (3) table in 20A degrees reverse Trendelenburg with the legs flexed 45A degrees upward at the hips (beach chair position), (4) table horizontal with the legs flexed 45A degrees upward at the hips, and (5) table in 20A degrees Trendelenburg with the legs flat. The positions were performed in a random order, and the first position was repeated after the last measurement. Repeated measure analysis of variance was used to compare inflated volumes among the five positions. A significant difference in inflated volume was found between the five body positions (P = 0.042). Compared with the mean inflated volume for the supine position (3.22 +/- A 0.78 l), the mean inflated volume increased by 900 ml for the Trendelenburg position or when the legs were flexed at the hips, and decreased by 230 ml for the reverse Trendelenburg position. The Trendelenburg position for lower abdominal surgery and reverse Trendelenburg with flexing of the legs at the hips for upper abdominal surgery effectively improved the workspace in obese patients, even with full muscle relaxation.