Comparison of the Effects of Normocapnia and Mild Hypercapnia on the Optic Nerve Sheath Diameter and Regional Cerebral Oxygen Saturation in Patients Undergoing Gynecological Laparoscopy with Total Intravenous Anesthesia

Cerebral hemodynamics may be altered by hypercapnia during a lung-protective ventilation (LPV), CO2 pneumoperitoneum, and Trendelenburg position during general anesthesia. The purpose of this study was to compare the effects of normocapnia and mild hypercapnia on the optic nerve sheath diameter (ONSD), regional cerebral oxygen saturation (rSO2), and intraoperative respiratory mechanics in patients undergoing gynecological laparoscopy under total intravenous anesthesia (TIVA). Sixty patients (aged between 19 and 65 years) scheduled for laparoscopic gynecological surgery in the Trendelenburg position. Patients under propofol/remifentanil total intravenous anesthesia were randomly assigned to either the normocapnia group (target PaCO2 = 35 mmHg, n = 30) or the hypercapnia group (target PaCO2 = 50 mmHg, n = 30). The ONSD, rSO2, and respiratory and hemodynamic parameters were measured at 5 min after anesthetic induction (Tind) in the supine position, and at 10 min and 40 min after pneumoperitoneum (Tpp10 and Tpp40, respectively) in the Trendelenburg position. There was no significant intergroup difference in change over time in the ONSD (p = 0.318). The ONSD increased significantly at Tpp40 when compared to Tind in both normocapnia and hypercapnia groups (p = 0.02 and 0.002, respectively). There was a significant intergroup difference in changes over time in the rSO2 (p < 0.001). The rSO2 decreased significantly in the normocapnia group (p = 0.01), whereas it increased significantly in the hypercapnia group at Tpp40 compared with Tind (p = 0.002). Alveolar dead space was significantly higher in the normocapnia group than in the hypercapnia group at Tpp40 (p = 0.001). In conclusion, mild hypercapnia during the LPV might not aggravate the increase in the ONSD during CO2 pneumoperitoneum in the Trendelenburg position and could improve rSO2 compared to normocapnia in patients undergoing gynecological laparoscopy with TIVA.

Hydromorphone Protects against CO2 Pneumoperitoneum-Induced Lung Injury via Heme Oxygenase-1-Regulated Mitochondrial Dynamics

Various pharmacological agents and protective methods have been shown to reverse pneumoperitoneum-related lung injury, but identifying the best strategy is challenging. Herein, we employed lung tissues and blood samples from C57BL/6 mice with pneumoperitoneum-induced lung injury and blood samples from patients who received laparoscopic gynecological surgery to investigate the therapeutic role of hydromorphone in pneumoperitoneum-induced lung injury along with the underlying mechanism. We found that pretreatment with hydromorphone alleviated lung injury in mice that underwent CO2 insufflation, decreased the levels of myeloperoxidase (MPO), total oxidant status (TOS), and oxidative stress index (OSI), and increased total antioxidant status (TAS). In addition, after pretreatment with hydromorphone, upregulated HO-1 protein expression, reduced mitochondrial DNA content, and improved mitochondrial morphology and dynamics were observed in mice subjected to pneumoperitoneum. Immunohistochemical staining also verified that hydromorphone could increase the expression of HO-1 in lung tissues in mice subjected to CO2 pneumoperitoneum. Notably, in mice treated with HO-1-siRNA, the protective effects of hydromorphone against pneumoperitoneum-induced lung injury were abolished, and hydromorphone did not have additional protective effects on mitochondria. Additionally, in clinical patients who received laparoscopic gynecological surgery, pretreatment with hydromorphone resulted in lower serum levels of club cell secretory protein-16 (CC-16) and intercellular adhesion molecule-1 (ICAM-1), a lower prooxidant-antioxidant balance (PAB), and higher heme oxygenase-1 (HO-1) activity than morphine pretreatment. Collectively, our results suggest that hydromorphone protects against CO2 pneumoperitoneum-induced lung injury via HO-1-regulated mitochondrial dynamics and may be a promising strategy to treat CO2 pneumoperitoneum-induced lung injury.

Effect of CO2 Pneumoperitoneum on Liver Function Following Laparoscopic Cholecystectomy

Background: Laparoscopic provides access to abdominal cavity for both diagnostic and therapeutic surgical interventions which were previously only possible through laparotomy. Recent studies have shown marked rise in serum liver enzymes after laparoscopic surgeries which is considered to be related to the impaired liver and splanchnic perfusion. The present study has been carried out with the aim to comprehend changes in liver enzymes after laparoscopic vs conventional cholecystectomy and the effects of these on outcomes of surgery. Subjects and Methods: Between January 2018 and June 2019, 100 patients with symptomatic gall stones which were eligible for cholecystectomy were enrolled in this prospective clinical observational trial. Randomisation to laparoscopic or open cholecystectomy was performed by using a sealed envelope technique just before surgery. All cases were operated by the same consultant surgeon with a standard anaesthetic protocol. Liver function tests were performed before surgery, at 24 hours and day seven postoperatively. Results: In the laparoscopic group, a statistically significant rise in liver enzymes both aspartate aminotransferase and alanine aminotransferase was observed after 24 hrs of surgery as compared to preoperative values (p<.001) and then again touching normal serum level on 7th day postoperatively. Whereas in open cholecystectomy patients, only a slight variation in the liver enzymes was observed, which was not significant compared to preoperative level (p>.05). No statistically significant changes in serum level of GGT, ALP and bilirubin was seen in either group. No mortality or bile duct injury was observed in this study. Conclusion: Transient elevation in level of liver enzymes occurs after cholecystectomy in both open and laparoscopy group but more in laparoscopic arm attributed to CO2 pneumoperitoneum with possibly some other factors contributing to this. These changes return to normal in a week time after the procedure, and no major complication is generally seen in these patients with normal preoperative liver function, but these temporary derangements at times may be of concern to surgeons for its implication to the integrity of biliary tract.