Lactate metabolism during laparoscopic cholecystectomy: Comparison betweenCO2 pneumoperitoneum and abdominal wall retraction

Recent reports have implicated CO2 pneumoperitoneum for laparoscopic surger y in the occurrence of postoperative mesenteric ischemia. With this kind of surgery, the increase in blood lactate levels has been attributed to anaer obic metabolism, probably due to tissue ischemia induced by high intraabdom inal pressure (LAP). The aim of this study was to evaluate the metabolic re percussion of CO2 pneumoperitoneum during laparoscopic cholecystectomy (LC) . This was a prospective randomized study of CO2 pneumoperitoneum (PP group , n = 19) versus abdominal wall retraction (AWR group, n = 15). Demographic data were collected preoperatively. Four-trocar LC was performed with eith er a CO2 pneumoperitoneum (IAP of 12 mmHg) or abdominal wall retraction (ab dominal wall pressure 6-10 kp). Intraoperative and postoperative blood samp les were collected and lactate levels determined by enzymatic analysis. Rep eated measures analysis of variance (MANOVA) was used for statistical analy sis. Significance was evaluated at p < 0.05. The groups were shown to be ho mogeneous. Lactate concentration, expressed as mean (SD), went from 25.4 (1 4.4) mg/dl at baseline to 18.9 (13.6) mg/dl 4 hours after surgery in the PP group and from 19.4 (6.1) mg/dl at baseline to 17.8 (14.7) mg/dl in the AW R group. No significant differences were found between groups intraoperativ ely (p = 0.116) or postoperatively (P = 0.99). Our study did not show signi ficant differences in blood lactate levels during LC with CO2 pneumoperiton eum compared to the same procedure with abdominal wall retraction.