Study background and aims: Laparoscopic cholecystectomy is one of the most frequently performed interventions in departments of general surgery. One of the most important aims in achieving perioperative stability of these patients is diminishing the impact of general anesthesia on the hemodynamic stability and the optimization of anesthetic drug doses based on the individual clinical profile of each patient. The objective of this study is the evaluation of the impact monitoring the depth of anesthesia through Entropy (state entropy – SE and response entropy -RE) has on the hemodynamic stability and on the doses of volatile anesthetic. Material and Methods: This is a prospective, observational, randomized, monocentric study carried out between January 2019 and December 2019 in the Clinic of Anesthesia and Intensive Care from the “Pius Brînzeu” Emergency County Hospital in Timișoara, Romania. The patients included in the study were divided in two study groups; patients in Group A (target group) received multimodal monitoring that included monitoring of standard parameters and of Entropy (SE and RE), while patients in Group B (control group) only received standard monitoring. Anesthetic dose in group A were optimized to achieve a target entropy of 40-60. Results: 68 patients met the inclusion criteria and were allocated to one of the two study groups, Group A (N=43) and Group B (N=25). There were no statistically significant differences identified between the two groups for both demographical and clinical data (p>0.05). Statistically significant differences have been identified for the number of hypotensive episodes (p = 0.011, 95% CI 0.1851 to 0.7042) and for the number of episodes of bradycardia (p < 0.0001, 95% CI 0.3296 to 0.7923). Moreover, there was a significant difference in the Sevoflurane consumption between the two study groups (p = 0.0498, 95% CI -0.3942 to 0.9047). Conclusions: The implementation of the multimodal monitoring protocol that includes the standard parameters and the measurement of Entropy for determining the depth of anesthesia (SE and RE) lead to a considerable improvement in perioperative hemodynamic stability. Optimizing the doses of anesthetic drugs based on the individual clinical profile of each patient leads to a considerable decrease in drug consumption as well as to a lower incidence of hemodynamic side-effects.

Worldwide, the prevalence of surgery under general anaesthesia has increased significantly, on one hand because of modern anaesthetic and pain control techniques, and on the other hand because of better diagnosis and increased complexity of surgical technique. Together with the development of new concepts in the surgical field, the attention of researchers and clinicians turned to minimizing the impact of surgical trauma and offering minimal invasive procedures. This fact is due to the recent discoveries in the field of cellular and molecular mechanisms, that have revealed a systemic inflammatory and pro-oxidative impact that not only lasts in the perioperative period, but also impacts the long term, contributing to more difficult recovery, increased morbidity, and mortality, and finally a negative financial impact. Detailed molecular and cellular analysis have shown an overproduction of inflammatory and pro-oxidative species, that are responsible for an augmentation of the systemic inflammatory status and more difficult postoperative recovery. Moreover, it was shown that there are a series of changes in certain epigenetic structures, the most important being the microRNAs. Based on these findings, a series of modern, targeted therapeutic approaches have been proposed, with the final goal of blocking these mechanisms and reducing the redox state. Recent studies carried out had a positive clinical impact regarding antioxidant therapy and have shown that it can be used in the perioperative period with beneficial clinical impact. This review describes and details the most important molecular and cellular mechanisms that impact the surgical patient undergoing general anaesthesia, and it presents a series of antioxidant therapies that can reduce systemic inflammation.