Intestinal perfusion during pneumoperitoneum with carbon dioxide, nitrogen, and nitric oxide during laparoscopic surgery

Objective: To find out what effect insufflation pressure and type of gas have on intestinal perfusion during pneumoperitoneum. Design: Randomized, controlled, prospective, experimental study. Setting. University affiliated animal experimental laboratory, Sweden. Animals: Fasted, anaesthetised, domestic pigs of both sexes operated on laparoscopically (n= 7, weight 26-31 kg). Interventions: Insufflation of carbon dioxide (CO 2 ), nitric oxide (NO), or nitrogen (N 2 ) at intra-abdominal pressures of 0, 5, 10, 15 and 20 mm Hg. Main outcome measures: Cardiac output, portal blood flow, and jejunal mucosal perfusion. Results. Cardiac output decreased during N 2 and NO (15, 20 mm Hg) but not during CO 2 insufflation because of an accompanying tachycardia. Portal flow decreased during insufflation with N 2 and NO (15, 20 mm Hg) and CO 2 (20 mm Hg). Jejunal perfusion was reduced during N 2 and NO insufflation (5-20 mm Hg) but remained unchanged during CO 2 insufflation (5-20 mm Hg). Conclusions: Insufflation with CO 2 maintained jejunal mucosal perfusion, probably as a result of hypercarbia as N 2 at equal pressures reduced mesenteric flow. The vasodilator NO provided no haemodynamic benefit.