Comparison between Low- and Standard Pressure Pneumoperitoneum on Optic Nerve Sheath Diameter in Patients Undergoing Laparoscopic Cholecystectomy: A Double-blind, Randomized Clinical Trial

Abstract Background: Laparoscopic cholecystectomy can be performed with low-pressure pneumoperitoneum (<10 mm Hg) or standard pressure pneumoperitoneum (12–14 mm Hg). The objective of the study is to compare the changes in the ultrasonographic measurement of optic nerve sheath diameter (ONSD) resulting from low- and standard pressure pneumoperitoneum in patients undergoing laparoscopic cholecystectomy. Patients and Methods: In this prospective double-blind randomized study, seventy patients including both men and women between 18 and 65 years of age with ASA physical status I–II scheduled for elective laparoscopic cholecystectomy under general anesthesia were included. They were randomized into two groups – Group S (standard pressure pneumoperitoneum (12 mm Hg) and Group L (low-pressure pneumoperitoneum (8 mm Hg) based on the intra-abdominal pressure (IAP) used during surgery. ONSD was measured at four different time intervals – 5 min after supraglottic airway device insertion (T0), 15 min after pneumoperitoneum (T1), 30 min after pneumoperitoneum (T2), and 10 min after deflation of pneumoperitoneum (T3). Duration of pneumoperitoneum, hemodynamic parameters, and ventilatory parameters were also recorded. Results: Demographic parameters were comparable between both groups. There was no significant change in the ONSD between the two groups at T0, T1, and T3 time points ( P = 0.480, 0.091, and 0.053, respectively). There was a significant increase in ONSD in group S in comparison to group L 30 min (T2) after pneumoperitoneum ( P < 0.001). Hemodynamic parameters were comparable between two groups at all measured time points. Conclusion: Based on our study, we thus conclude that low-pressure pneumoperitoneum is a safe approach in patients at risk of increased intracranial pressure.