Low and standard intra-abdominal pressure during laparoscopic cholecystectomy: An observational study based on colorimetric determination of serum concentration variation of the radical cation of N,N-DIETHYL-para-PHENYLDIAMINE

Background: This prospective observational open-label cohort study on patients submitted for elective laparoscopic cholecystectomy is aimed to investigate the association of low (8-10 mm Hg) and high (11-14 mm Hg) intra-abdominal pressure with the variation of serum colorimetric determination of the radical cation of N,N-Diethyl-para-phenyldiamine (DEPPD), measured immediately before pneumoperitoneum and 10 min after deflation, and intended as a proxy of oxidative stress. Methods: In 117 patients, subdivided into low-pneumo (n. 49 pts.) and high-pneumo (n. 68 pts.) groups, biochemical analyses were performed and analyzed by T tests and a multivariable regression model. Results: The results of the biochemical analyses showed that the variation of the radical cation of DEPPD values resulted in no significant difference between low and high pneumoperitoneum. Moreover, low intra-abdominal pressure compared with high pressure was not significantly associated with age, body mass index, and previous abdominal surgery. On the contrary, both the female gender and the iatrogenic gallbladder perforation were significantly associated with a positive variation of the radical cation of DEPPD. Notably, when the operation length was longer than 45 minutes, a significant association with a negative variation was observed. Conclusions: This study on patients submitted for elective laparoscopic cholecystectomy, despite some limitations, suggested that the use of a low-pressure pneumoperitoneum is not associated with a postoperative lower production of oxidants compared with standard pressure.