Lactate Levels and Acid-Base Equilibrium in High- and Low-Pressure CO2 Pneumoperitoneum for Laparoscopic Cholecystectomy

Abstract

Background: The observation of haemodynamic and metabolic impairment related to CO2 pneumoperitoneum and postoperative mesenteric ischemia reports following laparoscopic procedures have raised concern about local and systemic effects of increase intra-abdominal pressure during laparoscopic procedures. This study aimed to evaluate the metabolic and acid base responses of using high-pressure versus low-pressure pneumoperitoneum in patients undergoing laparoscopic cholecystectomy in a prospective randomized clinical trial. Methods: Twenty ASA I-II patients scheduled for elective laparoscopic cholecystectomy were randomly allocated to one of the two study groups: high pressure pneumoperitoneum (12–14 mm Hg; HPP group; n = 10) versus low-pressure pneumoperitoneum 6–8 mm Hg (LPP group; n = 10) undergoing laparoscopic cholecystectomy. Arterial blood gases and lactate Levels were determined after induction of anaesthesia (before pneumoperitoneum), then after 10 min then 30 min after insufflations and at the end of surgery and 1 hour postoperatively. Nurses in postoperative recovery unit reported pain assessment which started postoperatively until 3 hours on a 10-mm VAS (0–10). Statistical significance was established at P < 0.05. Results: Bicarbonate was significantly (P < 0.0412) lower in high-pressure group at 30 min & 60 min after insufflations. In high-pressure group lactate levels increased significantly as compared to low-pressure group at 30 minutes after the establishment of abdominal pneumatic inflation (P < 0.006) and remained significantly increased (P < 0.001) until the end of surgery and one hour thereafter (P < 0.001). The mean postoperative pain score during second hour (VAS) in HPP group was 7.4 (1.17) which was significantly (P < 0.006) higher than pain score in LPP group 5.0 (1.89). Shoulder tip pain was reported in 3 patients of high-pressure group and only one patient of lower-pressure group. Conclusion: High-pressure pneumoperitoneum caused statistically significant elevation in the arterial lactate level intraoperatively until one hour postoperatively. It also caused higher pain score and shoulder tip pain.